UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 20202021

For the transition period from             to             

Commission File No. 001-37627

WAVE LIFE SCIENCES LTD.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: +65 6236 3388

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ☐    No  ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act.       Yes  ☐    No  ☒

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  ☒    No  ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).    Yes  ☒    No  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of ‘‘large accelerated filer,’’ ‘‘accelerated filer,’’ ‘‘smaller reporting company,’’ and ‘‘emerging growth company’’ in Rule 12b–212b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ☐    No  ☒

The aggregate market value of the registrant’s voting and non-voting ordinary shares held by non-affiliates of the registrant (without admitting that any person whose shares are not included in such calculation is an affiliate) computed by reference to the price at which the ordinary shares were last sold as of the last business day of the registrant’s most recently completed second fiscal quarter (June 30, 2020)2021) was $267,103,358. $269,680,028.

The number of outstanding ordinary shares of the registrant as of February 22, 202125, 2022 was 48,997,368.60,844,495.

DOCUMENTS INCORPORATED BY REFERENCE

If the Registrant’s Definitive Proxy Statement relating to the 20212022 Annual General Meeting of Shareholders (the “Proxy Statement”) is filed with the Commission within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K, then portions of the Proxy Statement will be incorporated by reference into Part III of this Annual Report on Form 10-K. If the Proxy Statement is not filed within such 120-day period, then the Registrant will file an amendment to this Annual Report within such 120-day period that will contain the information required to be included or incorporated by reference into Part III of this Annual Report.

WAVE LIFE SCIENCES LTD.

ANNUAL REPORT ON FORM 10-K

TABLE OF CONTENTS

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Special Note Regarding Forward-Looking Statements

This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that relate to future events or to our future operations or financial performance. Any forward-looking statement involves known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by such forward-looking statement. In some cases, forward-looking statements are identified by the words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “future,” “goals,” “intend,” “likely,” “may,” “might,” “ongoing,” “objective,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “strategy,” “target,” “will” and “would” or the negative of these terms, or other comparable terminology intended to identify statements about the future, although not all forward-looking statements contain these identifying words. Forward-looking statements include statements, other than statements of historical fact, about, among other things: our ability to fund our future operations; our financial position, revenues, costs, expenses, uses of cash and capital requirements; our need for additional financing or the period for which our existing cash resources will be sufficient to meet our operating requirements; the success, progress, number, scope, cost, duration, timing or results of our research and development activities, preclinical studies and clinical trials, including the timing for initiation or completion of or availability of results from any preclinical studies and clinical trials or for submission, review or approval of any regulatory filing; the timing of, and our ability to, obtain and maintain regulatory approvals for any of our product candidates; the potential benefits that may be derived from any of our product candidates; our strategies, prospects, plans, goals, expectations, forecasts or objectives; the success of our collaborations with third parties; any payment that our collaboration partners may make to us; our ability to identify and develop new product candidates; our intellectual property position; our commercialization, marketing and manufacturing capabilities and strategy; our ability to develop sales and marketing capabilities; our estimates regarding future expenses and needs for additional financing; our ability to identify, recruit and retain key personnel; our financial performance; developments and projections relating to our competitors in the industry; our liquidity and working capital requirements; the expected impact of new accounting standards; and our expectations regarding the impact of COVID-19, and variants thereof, on our business, including our research and development activities, preclinical studies and clinical trials, supply of drug product, and our workforce.

Although we believe that we have a reasonable basis for each forward-looking statement contained in this report, we caution you that these statements are based on our estimates or projections of the future that are subject to known and unknown risks and uncertainties and other important factors that may cause our actual results, level of activity, performance or achievements expressed or implied by any forward-looking statement to differ. These risks, uncertainties and other factors include, among other things, our critical accounting policies and: the ability of our preclinical studies to produce data sufficient to support the filing of global clinical trial applications and the timing thereof; our ability to continue to build and maintain the company infrastructure and personnel needed to achieve our goals; the clinical results and timing of our programs, which may not support further development of our product candidates; actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials; our effectiveness in managing current and future clinical trials and regulatory processes; the success of our platform in identifying viable candidates; the continued development and acceptance of nucleic acid therapeutics as a class of drugs; our ability to demonstrate the therapeutic benefits of our stereopure candidates in clinical trials, including our ability to develop candidates across multiple therapeutic modalities; our ability to obtain, maintain and protect intellectual property; our ability to enforce our patents against infringers and defend our patent portfolio against challenges from third parties; our ability to fund our operations and to raise additional capital as needed; competition from others developing therapies for similar uses; the severity and duration of the COVID-19 pandemic; and the COVID-19 pandemic, and variants thereof, may negatively impact the conduct of, and the timing of enrollment, completion and reporting with respect to, our clinical trials; and any other impacts on our business as a result of or related to the COVID-19 pandemic, as well as other risks and uncertainties under the “Risk Factors” section of this Annual Report on Form 10-K and in other filings we make with the Securities and Exchange Commission.

Each forward-looking statement contained in this report is based on a combination of facts and factors currently known by us and our expectations of the future, about which we cannot be certain.

As a result of these factors, we cannot assure you that the forward-looking statements in this Annual Report on Form 10-K will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, these statements should not be regarded as representations or warranties by us or any other person that we will achieve our objectives and plans in any specified timeframe, or at all. We caution you not to place undue reliance on any forward-looking statement.

In addition, any forward-looking statement in this report represents our views only as of the date of this report and should not be relied upon as representing our views as of any subsequent date. We anticipate that subsequent events and developments may cause our views to change. Although we may elect to update these forward-looking statements publicly at some point in the future, we undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make.

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As used in this Annual Report on Form 10-K, unless otherwise stated or the context otherwise indicates, references to “Wave,” the “Company,” “we,” “our,” “us” or similar terms refer to Wave Life Sciences Ltd. and our wholly-owned subsidiaries.

The Wave Life Sciences Ltd. and Wave Life Sciences Pte. Ltd. names, the Wave Life Sciences mark, PRISM and the other registered and pending trademarks, trade names and service marks of Wave Life Sciences Ltd. appearing in this Annual Report on Form 10-K are the property of Wave Life Sciences Ltd. This Annual Report on Form 10-K also contains additional trade names, trademarks and service marks belonging to Wave Life Sciences Ltd. and to other companies. We do not intend our use or display of other parties’ trademarks, trade names or service marks to imply, and such use or display should not be construed to imply, a relationship with, or endorsement or sponsorship of us by, these other parties. Solely for convenience, the trademarks and trade names in this Annual Report on Form 10-K are referred to without the ® and ™ symbols, but such reference should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.

Summary of Risk Factors

We are providing the following summary of the risk factors contained in this Annual Report on Form 10-K to enhance the readability and accessibility of our risk factor disclosures. We encourage you to carefully review the full risk factors contained in this Annual Report on Form 10-K in their entirety for additional information regarding the material factors that make an investment in our securities speculative or risky. These risks and uncertainties include, but are not limited to, the following:

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PART I

Overview

We are a clinical-stage genetic medicines company committed to delivering life-changing treatments for people battling devastating diseases. Using PRISM™, our proprietary discovery and drug development platform that enables the precise design, optimization and production of novel stereopure oligonucleotides, we aspire to develop best in classbest-in-class medicines forthat target the transcriptome to treat genetically defined diseases with a high degree of unmet need.

We are developing oligonucleotides that target ribonucleic acid (“RNA”) and harness existing cellular machinery to either reduce the expression of disease-promoting RNA or proteins, or transform the production of dysfunctional mutant proteins intorestore the production of functional proteins.proteins, or modulate protein expression. By intervening at the RNA level, we have the potential to address diseases that have historically been difficult to treat with small molecules or biologics, while retaining the ability to titrate dose, modulate duration of effect, and avoid risk of permanent off-target genetic changes and other challenges associated with DNA editing or gene therapy approaches. The mechanisms that we are currently using to target RNA with our oligonucleotides include silencing, splicing, and ADAR (adenosine deaminases acting on RNA)-mediated RNA editing (“ADAR editing”). Oligonucleotides have additional advantages as a therapeutic class, including the ability to access multiple tissue types and the ability to modulate the frequency of dosing to ensure broad distribution within tissues over time. Oligonucleotides also have well-established manufacturing processes and validated test methods based on decades of improvements.improvements, as well as established regulatory, access and reimbursement pathways.

TheOur approach is based on the scientific insight that the biological machinery necessary to address genetic diseases already exists in human cells and can be controlled with the right tools. We have built a genetic toolkit comprised of multiple therapeutic modalities, including RNase-H mediated silencing, RNAi, splicing, and RNA base editing, all of which leverage learnings and optimizations from our PRISM platform and allow us to design built-for-purpose molecules to optimally address disease biology.  

Our A-to-I RNA base editing oligonucleotides we(“AIMers”) represent our newest therapeutic modality. AIMers are developingdesigned to correct single base mutations on RNA transcript, thereby avoiding permanent changes to the genome that occur with DNA-targeting approaches. Rather than using an exogenous editing enzyme, AIMers recruit proteins that exist in the body, called ADAR (adenosine deaminases acting on RNA) enzymes, which naturally possess the ability to change an adenine (A) to an inosine (I), which cells read as guanine (G). This approach enables simplified delivery and avoids the risk of irreversible off-target effects with DNA-targeting approaches. AIMers are short in length, fully chemically modified, and use novel chemistry, including proprietary PN backbone modifications and chiral control, which make them distinct from other ADAR-mediated editing approaches.

Our PRISM platform is built on the recognition that a significant opportunity exists to tune the pharmacological properties of oligonucleotide therapeutics by leveraging three key features of these molecules: sequence, chemistry, and stereochemistry. Our unique ability to control stereochemistry, which is a reality of chemically modified oligonucleotides, provides the resolution necessary to optimize pharmacological profiles. PRISM therefore enables us to design stereopure oligonucleotides, which are stereopurecomprised of molecules with atoms precisely and purposefully arranged in three-dimensional orientations at each linkage. These differ from the mixture-based oligonucleotides currently on the market or in development by others. A stereopure oligonucleotide is comprised of molecules with atoms precisely arranged in three-dimensional orientations at each linkage. Based on our preclinical studies, we believe that controlling the stereochemistry of each backbone position will allow usAdditionally, to optimize the pharmacological profile of our oligonucleotides by maximizing the potential therapeutic benefit while minimizing the potential for side effects and safety risks. To further mitigate pharmacological risks and potential manufacturing challenges, our approach focuses on designing short, chemically modified oligonucleotides without the need for complex delivery vehicles. Through our

Our work in developing stereopure oligonucleotides we have createdhas enabled the continued evolution of PRISM and continue to evolve PRISM, our proprietarydrug discovery and drug development platform.

PRISM enables us to targetprocess of selecting genetically defined diseases with stereopure oligonucleotides across multipletargets, identifying a sequence and applying the therapeutic modalities.modality we determine is best suited for the disease biology. We use our PRISM combines our unique abilityplatform engine to construct stereopure oligonucleotides withscreen candidates and optimize the pharmacologic profile based on predefined design principles, which reflect a deep understanding of how the interplay among oligonucleotide sequence, chemistry and backbone

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stereochemistry impacts key pharmacological properties. By exploringThrough continued exploration of these interactions throughusing iterative analysis of in vitro and in vivo outcomes and machine learning-driven predictive modeling, we also continue to definerefine our design principles that we deploy across programs to rapidly develop and manufacture clinical candidates that meet pre-defined product profiles. subsequent programs.

In August 2020, we publicly introduced our novel PN backbone chemistry modifications, which were discovered through PRISM and have been shown preclinically to increase potency, tissue exposuredistribution and durability of effect across various modalities. PN chemistry has been incorporated into all of our current clinical, preclinical and discovery-stage programs.

We have a robust and diverse pipeline of PN-modified, stereopure oligonucleotides, including our clinical silencing and splicing programs, as well as our AIMers. Our lead clinical development programs are focused ondesigned to treat genetic diseases within neurology. Our first stereopure therapeutic candidates in development, WVE-120101 and WVE-120102, are designed to selectively target mutant huntingtin (“mHTT”) and spare wild-type, or healthy, huntingtin (“wtHTT”) for the treatment of Huntington’s disease (“HD”). WVE-120101 and WVE-120102 are currently being studied in two Phase 1b/2a clinical trials, PRECISION-HD1 and PRECISION-HD2, and we expect to deliver data from both trials at the end of the first quarter of 2021. We also expect to initiate dosing in three new clinical trials with compounds containing our novel PN backbone chemistry modifications in 2021. These new programs include WVE-003, our mHTT SNP3 program for the treatment of HD, WVE-004, our C9orf72 program for the treatment of amyotrophic lateral sclerosis (“ALS”) and frontotemporal dementia (“FTD”), and WVE-N531, our Exon 53 program for the treatment of Duchenne muscular dystrophy (“DMD”). We continue to advance our ATXN3 program in SCA3. We are also pursuing additional programs in disorders of the central nervous system (“CNS”), including Alzheimer’samyotrophic lateral sclerosis (“ALS”), frontotemporal dementia (“FTD”), Huntington’s disease Parkinson’s disease,(“HD”), and others, in collaboration with Takeda Pharmaceutical Company Limitedmuscular dystrophies, including Duchenne muscular dystrophy (“Takeda”DMD”). In additionThese programs include:

With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to neurology, our pipeline includes programs intreat hepatic diseases including alpha-1 antitrypsin diseaseand our lead program is designed to treat alpha-1antitrypsin deficiency (“AATD”),. We expect to select an AATD AIMer development candidate and ophthalmologic disorders, specifically inherited retinal diseases. initiate IND-enabling toxicology studies in the third quarter of 2022.

We continue to invest in PRISM to continue tofurther evolve and apply the expanding capabilities and promise of our unique platform. We have also established and continue to enhance our internal current good manufacturing practices (“cGMP”) manufacturing capabilities to increase control and visibility of our drug substance supply chain, while continuing to innovate oligonucleotide manufacturing.

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Our Current Programs

Additional details regarding our lead therapeutic programs are set forth below.

Neurology

Huntington’s Disease (“HD”)WVE-004: HDIn ALS and FTD, we are advancing WVE-004, which uses our novel PN chemistry and preferentially targets the transcripts containing the hexanucleotide G4C2 expansion in the C9orf72 gene. In C9 BAC transgenic mice, WVE-004 led to substantial reductions in repeat-containing C9orf72 transcripts and dipeptide repeat (“DPR”) proteins that are sustained for at least six months, without disrupting total C9orf72 protein expression.

The FOCUS-C9 trial is a rare hereditary neurodegenerative disease that results in early deathglobal, multicenter, randomized, double-blind, placebo-controlled Phase 1b/2a clinical trial to assess the safety and tolerability of intrathecal doses of WVE-004 for which there is no cure. HD is caused by a mutation (i.e., an expanded CAG triplet repeat)patients with C9-ALS and/or C9-FTD. Additional objectives include measurement of polyGP proteins in the HTT gene, which results in productioncerebrospinal fluid (“CSF”), plasma and CSF pharmacokinetics and exploratory biomarker and clinical endpoints. The FOCUS-C9 trial is designed to be adaptive with dose level and dosing frequency being guided by an independent committee. Preclinical models that have established pharmacologic activity have informed the starting dose for this trial.

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In July 2021, we announced the initiation of mutant HTT (“mHTT”) protein. In HD patients, there is a progressive loss of neuronsdosing in the brain leadingFOCUS-C9 clinical trial. We expect to cognitive, psychiatricshare clinical data in 2022 to provide insight into the clinical effects of PN chemistry and motor disabilities. HD patients still possess wild-type (healthy) HTT (“wtHTT”) protein, which is importantenable decision making for neuronal function, and there is increasing evidence that wtHTT may be neuroprotective in an adult brain. Additionally, a dominant gain of function in mHTT protein and a concurrent loss of function of wtHTT protein may be important components of the pathophysiology of HD. Accordingly, suppression of wtHTT may have detrimental long-term consequences. A 2020 Nature publication (Poplawski, G.H.D., et al. Injured adult neurons regress to an embryonic transcriptional growth state. Nature 581, 77–82 (2020)) described results that involved conditional knockout of huntingtin in 4-month old mice (post-neuronal development), which demonstrated that huntingtin is at the center of the regeneration transcriptome and played an essential role in neural plasticity. In October 2019, at our Analyst and Investor Research Day, key opinion leaders in HD research presented data suggesting that wtHTT is neuroprotective in an adult brain; transport of key neurotrophic factors such as brain-derived neurotrophic factor (“BDNF”) are regulated by wtHTT levels; and HD may be caused by a dominant gain of function in mHTT and a loss of function of wtHTT protein. Further, the relative proportion of wtHTT to mHTT is critical based on evidence that suggests increased amount of wtHTT relative to mHTT may result in slower disease progression (measured by age-at-onset). Also, HD patients that lack wtHTT all together have significantly more severe disease, as measured by disease progression after symptom onset.WVE-004.

Our HD PortfolioWVE-003: : In HD, we are currently advancing three clinical programs. WVE-120101 and WVE-120102 are our first clinical programs in HD, where each isWVE-003, a distinct stereopure antisense oligonucleotide designed to selectively target aan undisclosed single nucleotide polymorphism (“SNP”), “mHTT SNP3”, associated with the disease-causing mutant huntingtin (mHTT)(“mHTT”) mRNA transcript within the HTT gene: rs362307 (“mHTT SNP1”) and rs362331 (“mHTT SNP2”), respectively. Our third program in HD, WVE-003, is also a stereopure antisense oligonucleotide designed to target an undisclosed SNP3, “mHTT SNP3.”gene. WVE-003 incorporates our novel PN backbone chemistry, modifications, as well as learnings from the first twoour first-generation HD programs. We initiated clinical development of WVE-003Targeting mRNA with the submission of a clinical trial application (“CTA”) in December 2020. Approximately 50% of the HD population carries SNP1 or SNP2, and, with overlap, up to 70% of the HD population carries SNP1, SNP2 or both. Approximately 40% of the HD population carries SNP3 and, with overlap, up to 80% of the HD population carries at least one of SNP1, SNP2 and/or SNP3. Targeting mRNAs

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with these SNPs allows us to lower expression of transcript from the mutant allele, while leaving the healthy transcript relatively intact. The healthy transcript is required to produce wtHTTintact, thereby preserving wild-type (healthy) huntingtin (“wtHTT”) protein, which is important for neuronal function. We commonly refer to this method (or approach) as “allele-selective targeting.” SNPs are naturally occurring variations within a given genetic sequence and in certain instances can be used to distinguish between two related copies of a gene where only one is associated with the expression of a disease-causing protein. Our allele-selective approach may also enable us to address the pre-manifest, or asymptomatic, HD patient population in the future. We have shown that by targetingIn preclinical studies, WVE-003 showed dose-dependent and selective reduction of mHTT SNP1 and mHTT SNP2 in preclinicalmRNA in vitro studies, the production of disease-causing proteins associated with HD can be selectively reduced. In addition, we have shown that by targeting mHTT SNP3 in preclinical in vitro studies, WVE-003 selectively reduces the expression, potent and durable knockdown of mHTT mRNA and by targeting mHTT SNP3 in preclinicalprotein in vivo studies,. A pharmacokinetic-pharmacodynamic (“PK-PD”) model for WVE-003 demonstrated durablebased on preclinical data predicts that WVE-003 may attain sufficient concentrations to engage mHTT transcript in both the cortex and potent knockdownstriatum and decrease expression of the mHTT mRNA.protein.

Phase 1b/2a Clinical Trials: PRECISION-HDThe SELECT-HD trial is a global clinical program consisting of the PRECISION-HD1 and PRECISION-HD2 clinical trials. PRECISION-HD1 and PRECISION-HD2 are two parallel, multicenter, randomized, double-blind, randomized, placebo-controlled Phase 1b/2a clinical trials evaluating WVE-120101 and WVE-120102, respectively, administered intrathecally, consisting of single-ascending dose and multiple-ascending dose portions. The primary objective of these two trials istrial to assess the safety and tolerability of intrathecal doses of WVE-120101 and WVE-120102, respectively, inintrathecally administered WVE-003 for patients with early manifest HD patients.HD. Additional objectives include measurement of total HTT proteinmHTT and mHTTwtHTT protein and exploratory pharmacokinetic, pharmacodynamic, clinical and MRImagnetic resonance imaging (“MRI”) endpoints. EachThe SELECT-HD trial is designed to be adaptive, with five multi-dose cohorts (2, 4, 8, 16,dose level and 32 mg), each with 12 patientsdosing frequency being guided by an independent committee. Preclinical models that have Stage I or Stage II HD, ages 25-65, whoestablished pharmacologic activity have screened positivelyinformed the starting dose for this trial. In September 2021, we announced the presenceinitiation of SNP1 or SNP2. Outside of the United States, we are conducting both the single-ascending dose and multiple-ascending dose portions of the PRECISION-HD1 and PRECISION-HD2 trials. In the United States, we received approvals to proceed with the single-dose portions of both trials. However, the FDA indicated to us that we cannot progress to the multiple-ascending dose portions of these trialsdosing in the United States unless we conduct an additional preclinical study and present the resulting data to the FDA for its review. For the single-dose portion of the PRECISION-HD1 trial in the United States, escalation to our highest proposed doses is subject to the FDA’s review and approval of additional monitoring plans. WVE-120101 and WVE-120102 have been granted orphan drug designation for the treatment of HD by the FDA.

PRECISION-HD2 trial:In December 2019, we announced initial clinical data from the ongoing PRECISION-HD2SELECT-HD trial. In an analysis comparing all patients treated with multiple intrathecal doses of WVE-120102 to placebo, a statistically significant reduction of 12.4% (p<0.05) in mHTT protein was observed in cerebrospinal fluid (“CSF”). An analysis to assess a dose response across treatment groups (2, 4, 8, or 16 mg) suggested a statistically significant response in mHTT reduction at the highest doses tested (p=0.03). WVE-120102 was generally safe and well tolerated across all cohorts. These topline data supported the addition of higher dose cohorts, and a 32 mg cohort was initiated in January 2020, which is fully enrolled. We expect to report biomarkershare clinical data in 2022 to provide insight into the clinical effects of PN chemistry and safety data from all cohorts of the PRECISION-HD2 trial, including all patients from the 32 mg cohort, at the end of the first quarter in 2021.enable decision making for WVE-003.

PRECISION-HD1 trialWVE-N531: The PRECISION-HD1 trial is fully enrolled up to the 32 mg cohort. We expect to report biomarker and safety data from all completed cohorts up to and including the 16 mg cohort at the end of the first quarter in 2021.

Open-label Extensions of PRECISION-HD1 and PRECISION-HD2: In October 2019, we initiated an open-label extension (“OLE”) of the PRECISION-HD2 trial outside of the United States for patients who participated in that trial. In February 2020, we also initiated an OLE of the PRECISION-HD1 trial outside of the United States for patients who participated in that trial. Along with data from the PRECISION-HD1 and PRECISION-HD2 trials, we expect to report data from patients who have received multiple doses of 8 or 16 mg of WVE-120101 or WVE-120102 in the OLE portions of the trials at the end of the first quarter of 2021.

WVE-003 clinical trial: In December 2020, we initiated clinical development of WVE-003 with the submission of a CTA. We expect to initiate dosing in a Phase 1b/2a clinical trial of WVE-003 of patients with HD in 2021.

Amyotrophic lateral sclerosis (“ALS”) and frontotemporal dementia (“FTD”): In ALS and FTD, we are advancing WVE-004, which preferentially targets the transcripts containing the hexanucleotide G4C2 expansion in the C9orf72 gene. WVE-004 is designed to minimize the impact on normal C9orf72 protein in patients, thereby reducing potential on-target risk. In vitro, WVE-004 potently and selectively reduced V3 transcripts in iPSC-derived motor neurons, which were derived from a patient carrying a C9orf72-repeat expansion. In C9 BAC transgenic mice, WVE-004 led to substantial reductions in repeat-containing C9orf72 transcripts and dipeptide repeat (DPR) proteins that are sustained for at least six months, without disrupting total protein expression.

WVE-004 clinical trial: InDecember 2020, we initiated clinical development of WVE-004 with the submission of a CTA. We expect to initiate dosing in a Phase 1b/2a clinical trial of WVE-004 for both patients with C9-ALS and patients with C9-FTD in 2021.

SCA3: In spinocerebellar ataxia 3 (“SCA3”), we are continuing to advance our program targeting ATXN3. SCA3 is a rare, hereditary (autosomal dominant), progressive, neurodegenerative disorder that is caused by a CAG-repeat expansion in the ATXN3 gene.

Additional CNS Disorders: We are collaborating with Takeda to advance genetically defined targets for the treatment of other CNS disorders, including Alzheimer’s disease and Parkinson’s disease. Under the terms of the agreement, we may collaborate with Takeda

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on up to six preclinical programs at any one time, during a four-year term. Takeda is entitled to exclusively license multiple preclinical programs from us during the term.

Duchenne Muscular Dystrophy (“DMD”): In DMD, we are advancing WVE-N531, which is designed to target exon 53 within the dystrophin gene. WVE-N531 is designed to cause the cellular splicing machinery to skip over this exon during pre-mRNA processing, which restores the dystrophin mRNA reading frame and enables production of truncated, but functional dystrophin protein. Exon-skipping produces dystrophin from the endogenous dystrophin gene (not micro or mini dystrophin expressed from a vector), under the control of native gene-regulatory elements, resulting in normal temporospatial expression. WVE-N531 will beis both our first splicing candidate and our first systemically administered candidate incorporating PN backbone chemistry modifications to be assessed in the clinic.

WVE-N531In September 2021, we announced the initiation of dosing in an open-label clinical trial: evaluating WVE-N531 as a treatment for boys with DMD who are amenable to exon 53 skipping. We expect to submit a CTAshare clinical data, including muscle biopsies, in 2022 to provide insight into the clinical effects of PN chemistry and enable decision making for WVE-N531 by the end of the first quarter in 2021.WVE-N531.

Hepatic

We are initially focused on developing AIMers to address genetic hepatic diseases. Our AIMers are relatively short and stable (fully chemically modified), which enables us to leverage clinically-proven N-acetyl galactosamine (“GalNAc”)-mediated delivery to hepatocytes with subcutaneous dosing.

Alpha-1 antitrypsin deficiency (“AATD”): We are leveraging our ADAR editing platform capabilities to develop a potentially novel treatment forOur AATD which is a rare, inherited genetic disorder that is commonly caused by a G-to-A point mutation in the Z allele of the SERPINA1 gene. This mutation leads to misfolding and aggregation of alpha-1 antitrypsin (“AAT”) protein in hepatocytes and a lack of functional AAT in the lungs. People with AATD typically exhibit progressive lung damage, liver damage or both, leading to frequent hospitalizations and potentially terminal lung disease and/or liver disease. While the few approved therapies for AATD modestly increase circulating levels of AAT in those with the lung pathology, there are no approved therapies to address the liver pathology. Approximately 200,000 people in the United States and Europe are homozygous for the Z allele, whichprogram is the most common form of severe disease. In November 2020, we announced thatfirst to leverage our first ADAR editing program would be for AATD. Our novel RNA editing platform capability that uses GalNAc-conjugated AIMers (RNA base editing oligonucleotides) and endogenous ADAR enzymes of A-to-I (G) base editing oligonucleotides, making this a potentially best-in-class modality for correcting the G-to-A disease-causing mutation in mRNA coded by the SERPINA1 Z allele. By correcting the single RNA base mutation, ADAR editing may provide an ideal approach for increasing circulating levels of wild-type AAT protein and reducing aggregation in the liver, thus simultaneously addressing both the lung and liver manifestations of the disease.

In a primary hepatocyte SERPINA1 Z cell model, we demonstrated that editing the Z allele mRNA back to wild-type prevents protein misfolding and increases secretion of edited AAT protein from hepatocytes. We expect to deliver in vivo data supporting the continuedselect an AATD AIMer development of our AATD programcandidate and initiate IND-enabling toxicology studies in the first halfthird quarter of 2021.

Ophthalmology

In ophthalmology, we have generated in vitro, ex vivo 2022.and in vivo data in preclinical studies that support the potential of our stereopure oligonucleotides for the treatment of rare, inherited eye diseases. Our preclinical data demonstrate that a single intravitreal injection of stereopure oligonucleotide in the eye of non-human primates (“NHPs”) resulted in greater than 95% knockdown of a target RNA in the retina for at least four months. Based on these data, our goal is to design candidates that could achieve a therapeutic effect with only two doses per year. Our pipeline includes two preclinical programs: Usher syndrome type 2A (“USH2A”) and retinitis pigmentosa due to a P23H mutation in the RHO gene (“RhoP23H”). In September 2020, we presented in vitro,ex vivo, and in vivo preclinical data on our USH2A program, which is designed to promote USH2A exon 13 skipping, and we presented in vitro and in vivo data on our RhoP23H program, which is designed to selectively silence RhoP23H transcripts. We also presented results from our first achievement of ADAR editing in NHP retina ex vivo using stereopure oligonucleotides.

Note on the COVID-19 Global Pandemic

The ongoing COVID-19 global pandemic, and variants thereof, is havingcontinues to have widespread, rapidly-evolving,rapidly evolving, and unpredictable impacts on global societies, economies, financial markets, and business practices. We are closely monitoring the impact of the pandemic and related developments, and our focus remains on safeguarding employee and patient health, while minimizing the negative effects on our business and continuing to advance the research and development of our therapeutic candidates. For discussion regarding the impact of the COVID-19 global pandemic on our business and financial results, see “Risk Factors” in Part I, Item 1A and “Management's Discussion and Analysis of Financial Condition and Results of Operations” in Part II, Item 7 of this Annual Report on Form 10-K.

Our Strategy

We are building a fully integrated genetic medicines company by leveraging PRISM to design, develop and commercialize optimized disease-modifying medicines for indications with a high degree of unmet medical need in genetically defined diseases. Our lead clinical programs are focused in neurology and are aimed at addressing HD, ALS, FTD, HD, and DMD.DMD using silencing and splicing modalities. We are also pursuing additional CNS programs in collaborationusing our RNA base editing modality to address hepatic indications using GalNAc-conjugated AIMers, with Takeda. Beyond neurology, our pipeline includes preclinical programs in hepatic diseases, including

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AATD, and ophthalmology.lead program aimed at treating AATD. In addition to driving clinical and preclinical programs, we are continuously investing in PRISM to fully unlock the potential of our unique and expanding platform capabilities.

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The key components of our strategy are as follows:

Oligonucleotides

The majority of traditional therapeutics, such as small molecules and biologics, work by interacting with proteins that contribute to the disease. However, there are thought to be a limited number of “druggable” proteins; it is currently estimated that approximately 80% of human protein targets cannot be addressed by these conventional approaches. In contrast, we believe that directing medicines to the RNA, which is critical to the production of proteins, rather than to the proteins themselves, has the potential to significantly increase the number of druggable targets. By intervening at the RNA level, we retain the ability to titrate dose, while avoiding permanent off-target genetic changes and other challenges associated with DNA editing or gene therapy approaches. We also believe that utilizing and building upon the established scientific, regulatory, operational and commercial knowledge base with regard to genetic medicines that target RNA gives us the best chance of success to rapidly deliver therapies to the patients who need them.

Nucleic acid therapeutics, including oligonucleotides, are an innovative class of drugs that can modulate the function of target RNAs to ultimately affect the production of disease-associated proteins or prevent the accumulation of pathogenic RNA species, which are emerging as important factors in human disease. Oligonucleotides can regulate protein and RNA via several different molecular mechanisms. These mechanisms can be broadly categorized as silencing, those that promote degradation of the target RNA, including antisense and RNAi; splicing, those that involve binding to the target RNA and modulating its function by promoting exon skipping; and ADAR-mediated RNA-editing.

The unique capability of oligonucleotides to address a wide range of genomic targets that impact multiple therapeutic areas creates potentially significant market opportunities for us to develop molecules to treat a broad spectrum of human diseases, including diseases where no medicines currently exist or for which existing treatments are not optimal.

The oligonucleotides we are currently developing employ the following molecular mechanisms:

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Stereochemistry of Oligonucleotide Backbone Modifications Result in Complex Drug MixturesImpacts Pharmacology

Oligonucleotides are comprised of a sequence of nucleotides—the building blocks of RNA and DNA—that are linked together by a backbone of chemical bonds. In nucleic acid molecules that have not been modified for therapeutic use, the nucleotides are linked by phosphodiester (“PO”) bonds, as shown below.

bonds. Such unmodified nucleic acid molecules are unsuitable for use as therapeutics because they are rapidly degraded, are rapidly cleared by the kidneys and are taken up poorly by targeted cells.

Backbone chemistry modifications such as the phosphorothioate (“PS”) modification, one of the most common backbone modifications used in oligonucleotides, can improve the stability, biodistribution and cellular uptake of oligonucleotides.

A consequence of introducing backbone modifications, such as PS modifications, into an oligonucleotide is that it also introduces a chiral center at each phosphorus, creating stereoisomers designated as either an “Sp” or “Rp” isomer. As shown below, these stereoisomers have identical chemical compositions but different three-dimensional arrangements of their atoms and consequently have different chemical and biological properties.

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During traditional oligonucleotide synthesis, the isomeric configuration at each chiral backbone modification is random (either Rp or Sp). Because oligonucleotides contain a string of nucleotides with associated chiral backbone modifications, the synthesis process generates, resulting in a complex mixture containing many stereoisomers.stereoisomers (known as diastereomers). Using PS modifications as an example, each PS linkage doublesintroduces a chiral center, thereby doubling the number of stereoisomers in the product, so that a traditional preparation of a PS-containing oligonucleotide contains 2^N stereoisomers, where N represents the number of PS modifications.  As shown below, a traditional, fully PS-modified antisense oligonucleotide (20 nucleotides in length, 19 PS modifications) is a mixture of over 500,000 stereoisomers, each having the same nucleotide sequence but differing in the stereochemistry along their backbones.

Stereoisomers can possess different chemical and pharmacological properties. For example, certain stereoisomers can drive the therapeutic effects of a drug while others can be less beneficial or can even contribute to undesirable side effects. The greater the variation among a drug’s constituent stereoisomers, the greater the potential to diminish the drug’s efficacy and safety when it’sit is a complex mixture.

Prior to the development of our technology, it was not possible to create stereopure oligonucleotides, meaning molecules where the configuration of each chiral backbone linkage is precisely controlled during chemical synthesis. Moreover, because of the sheer number of stereoisomers present in a mixture, it would be impractical, if not impossible, to physically isolate the most therapeutically optimal stereoisomer from within a mixture. For these reasons, all chiral backbone-modified oligonucleotides currently on the market and in development by others are mixtures of many stereoisomers, which we believe are not optimized for stability, catalytic activity, efficacy or toxicity.

In small molecule therapeutics, U.S. regulators have long sought to eliminate the risks potentially posed by drug mixtures containing multiple stereoisomers. Since 1992, the FDA has recommended full molecular characterization of stereoisomers within small-molecule drug mixtures. Historically, it has not been possible to achieve such characterization for nucleic acid therapeutic drug mixtures, which can contain tens of thousands to millions of distinct pharmacological entities. Based on our published and ongoing preclinical studies, we believe that we can design and synthesize stereopure chemically modified oligonucleotides that demonstrate superior pharmacological properties compared with mixture-based oligonucleotides. We believe that PRISM has the potential to set a new industry standard for the molecular characterization of complex nucleic acid therapeutic drug mixtures.

We continue to develop new types of backbone modifications, other than PS modifications, that can be chirally controlled with our technology.

PRISM: Our proprietary discovery and drug development platform

Through PRISM, our proprietary discovery and drug development platform, we have discovered and expect to continuously elaborate on the relationships between the chemical makeup of an oligonucleotide, including the three-dimensional orientation or arrangement of its atoms, and its pharmacology (i.e., stability of the drug, activity against the target, specificity for the target and safety of the drug). For example, we realized the impact of our novel PN backbone chemistry in vivo in preclinical studies only because we evaluated its impact in the context of an otherwise stereopure backbone (Kandasamy et al., 2022; doi: 10.1093/nar/gkac037,

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Kandasamy et al., 2022; doi: 10.1093/nar/gkac018). In addition, we have defined relationships between various 2’-sugar modifications to the nucleotide (such as methoxy, methoxyethyl, fluoro, locked), and the chemistry and stereochemistry of the backbone that enhances oligonucleotide pharmacology, providing an enhanced therapeutic profile.

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Our rational process for designing stereopure oligonucleotides, which is based on the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry, allows us to selectively optimize for the molecular mechanismtherapeutic modality in order to generate best-in-class oligonucleotides. With PRISM, we leverage the diversity created by backbone stereochemistry to expand the parameters that we explore to optimize oligonucleotides. We are using these ongoing discoveries to guide our drug development activities, which we believe will lead to medicines that are more specific, can be dosed at lower concentrations, less frequently, or some combination of these characteristics as well as with improved therapeutic profiles.

Advantages of Our Approach

We believe that PRISM is a significant advancement in the development of oligonucleotides. The advantages of our approach include:

Our Proprietary Chemistry

Backbone Stereochemistry

In our foundational Nature Biotechnology paper (Iwamoto N, et al. Nature Biotechnol. 2017;35(9):845-851), we described our studies using our proprietary chemistry to design and synthesize stereopure oligonucleotides and oligonucleotide mixtures based on mipomersen. These and other preclinical studies have demonstrated that stereochemistry and pharmacology are directly related, and that by controlling stereochemistry, we can impact multiple aspects of pharmacology, including stability, catalytic activity, efficacy, specificity, and safety. We studied mipomersen because, at that time, it was the only systemically administered nucleic acid therapeutic approved for commercialization, and documents from the regulatory bodies that evaluated mipomersen for marketing approval were publicly available. Mipomersen (formerly marketed under the brand name Kynamro, now discontinued) received FDA approved for the treatment of homozygous familial hypercholesterolemia in 2013 and is designed to silence production of Apolipoprotein B (“APOB”) via an antisense mechanism.

Mipomersen, an oligonucleotide containing 20 nucleotides and 19 PS modifications, is synthesized by traditional oligonucleotide chemistry; thus, it is a mixture of over 500,000 different stereoisomers (2¹⁹ = 524,288). We rationally designed and synthesized individual stereoisomers of mipomersen, each having position-specific and distinct stereochemistry, and conducted studies comparing these defined stereoisomers with the mipomersen stereomixture. These and other preclinical studies have demonstrated that stereochemistry and pharmacology are directly related, and that by controlling stereochemistry, we can impact multiple aspects of pharmacology, including stability, catalytic activity, efficacy, specificity, and safety.

We have subsequently published multiple additional evidence supportingmanuscripts since the ideastart of 2021 that provide evidence that stereopure oligonucleotides can be developed to have superior pharmacology to stereorandom including in our Translational Vision Science & Technology paper (Byrne M, et al. Trans Vis Sci Tech. 2021; 10(1):23) and our Nature Communications paper (Liu Y, et al. Nature Communications. 2021; 12:847), whicholigonucleotides; These manuscripts are discussed in more depth in the “Business - Therapeutic Programs - Ophthalmology” and “Business - Therapeutic Programs - Amyotrophic Lateral Sclerosis and Frontotemporal Dementia” sections, respectively.listed below:

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PN Backbone Chemistry Modifications

Our initial investigations into backbone chemistry and stereochemistry on oligonucleotide pharmacology focused on the widely used PO and PS backbones because they are amenable to all nucleic acidoligonucleotide modalities. In August 2020, we announced the introduction of novel PN backbone chemistry modifications (“PN”) to our repertoire of backbone modifications, which involve replacing a non-bridging oxygen atom with a nitrogen-containing moiety, as shown below.

Specifically, we

We have incorporated one of these PN modifications – which containsspecifically phosphoryl guanidine – into oligonucleotide compounds. As with PS modifications, PN modifications are chiral, and we have the capacity to control PN backbone stereochemistry. Unlike PS modifications, PN modifications are neutral, meaning that the negative charge of the oligonucleotide is reduced with every PN modification added to the backbone. In preclinical experiments, we have demonstrated that judicious use of PN backbone chemistry modifications in stereopure oligonucleotides have generally increased potency, tissue exposure and durability of effect across our silencing, splicing and editing modalities.

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Applications of PRISM Across Multiple Therapeutic ModalitiesModality Types

Using PRISM, we have designed and optimized diverse sets of stereopure oligonucleotides, which allows us to characterize and compare the behavior of various stereoisomers. With each new target, we gain insight into how the interplay between sequence, chemistry, including 2’-modifications and backbone chemistry, and stereochemistry impacts activity, and we build these learnings into our future programs. Hit rates, defined as the percentage of total oligonucleotides screened that yielded activity in the screening assay, in our primary screens performed with oligonucleotides in a stereorandom format have ranged from 10% to 15%. By applying learnings from early programs to generate new screening formats, hit rates have risen, with our most productive screens reaching hit rates of up to 80%. This improving hit rate illustrates that the right combination of chemistry and stereochemistry can yield activity through sequences that would be inactive or only mildly active in a stereorandom format, supporting our belief that the activity of oligonucleotides depends on an interplay between sequence, chemistry and backbone stereochemistry.

In the next section, we describe three distinctdifferent therapeutic modalities for which we have used PRISM to optimize stereopure oligonucleotides.

Silencing -– RNase H-mediated degradation and RNAi

We have used Malat1, a long noncoding RNA that is ubiquitously expressed and enriched in the nucleus, as a proof-of-concept target for our RNase H-silencing programs. Using PRISM, we can produce stereopure PN-modified oligonucleotides that promote potent and specific RNase HRNA transcript silencing activity in preclinical experiments.

RNase H-mediated degradation: In our Nucleic Acids ResearchTranslational vision science & technology paper (Byrne M,(Kandasamy et al. Trans Vis Sci Tech. 2021;10(1):23), 2022; doi: 10.1093/nar/gkac018), we describe an optimized stereopure antisense oligonucleotide, MALAT1-200, that shows enhanced potency, efficacy, and durability of MALAT1 RNA depletion in the eye compared with its stereorandom counterpart, MALAT1-181, in mouse and NHP eyes upon IVT injection. Because MALAT1-200 shares the same sequence and chemical modification pattern as MALAT1-181, it represents one stereoisomer of the more than 65,000 stereoisomers that comprise MALAT1-181. These results provide proof of concept, consistent with our prior work, that the identification of stereoisomers with desirable activity profiles can yield benefits over mixtures of randomly generated stereoisomers.

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In the figure below on the left, the PK-PD relationship is shown for stereorandom (50 ug) and stereopure (50 ug) oligonucleotides in the posterior position of the eye at 1 week. The percentage of Malat1 remaining is plotted with respect to the concentration of oligonucleotide detected in the tissue (n=7); each point represents data from one treated eye. The stereopure oligonucleotide was more active than the stereorandom oligonucleotide, and we also observed greater tissue exposure with the stereopure oligonucleotide than the stereorandom. In the figure below on the right, the schematic representation of a longer-term study in NHPs is shown, which evaluated the durability of a single 450 ug dose of stereopure oligonucleotide. Animals were dosed with a single 450 ug IVT injection on day 0 (d0) and samples were evaluated on days 8 (d8, 1 week later, blue arrows), 56 (d56, 2 months later), and 112 (d112, 4 months later). MALAT1 expression at d8, d56, and d112 after treatment with phosphate-buffered saline (“PBS”) (beige, 0 ug) or stereopure oligonucleotide (blue, MALAT1-200) in NHP retina. At 1 week, 2 months, and 4 months post injection, MALAT1 RNA levels in the treated retina were decreased by ∼95% compared with PBS-treated control.

We have determined the X-ray crystal structure to a resolution of 1.3 Å (shown below) of RNase H1 (green) bound to a heteroduplex containing a surrogate target mRNA (red) and a stereopure oligonucleotide (blue). In our Nature Biotechnology paper, we predicted that amino acids in the RNase H1 phosphate-binding pocket would make stereochemically differentiated contacts with three consecutive phosphates in the oligonucleotide backbone. In this structure, the phosphate-binding pocket is shown to contact the 3’-SpSpRp-5’ phosphorothioate linkages in the stereopure oligonucleotide. This structure confirms our hypothesis and supports our findings that optimal placement of backbone stereochemistry in an oligonucleotide can provide control over the activity of RNase H1.

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To illustrateillustrated the impact of PN backbone chemistry modifications for aan RNase-H mediated silencing modality,modality. In addition to the data reported in the paper, we have performed screens for identifying RNaseH-targeting sequences in iCell neurons in vitro using free uptake. This screen was initially performed with stereopure molecules with PS and PO backbone chemistry modifications, and the oligonucleotides are rank-ordered from left to right according to their potency. Next, we performed a head-to-head comparison with molecules that contained the same sequence and the same 2’-ribose chemistry, but with the addition of PN chemistry at select locations in the backbone. The introduction of a few PN linkages signficantly increases the potency of the vast majority of the stereopure PS / PO molecules, with ~80% of them yielding at least 75% knockdown. These results, shown below, suggest we are able to target sequence space that would otherwise be inaccessible.

Moving in vivo, we have demonstrated potent silencing activity of multiple targets in the incorporationCNS of PN backbone chemistry modifications has had a significant impact on our silencing molecules.non-human primates with stereopure, PN-modified oligonucleotides. In the results shown below for an undisclosed target, non-human primates received a single 12 mg dose by intrathecal injection. One month after administration, we observed that the candidate was widely distributed across the CNS, including the spinal cord, cerebral cortex and hippocampus. This single dose led to approximately 90% knockdown of the targetsubstantial and widespread mRNA across CNS tissues.reduction one month after administration.  

aCSF: artificial cerebrospinal fluid; CTX: cortex; HP: hippocampus; CSC: cervical spinal cord; LSC: lumbar spinal cord; STR: striatum

16RNAi: We have also applied our stereopure PS and PN modifications to the RNAi silencing modality using double-stranded siRNAs and demonstrated potent and durable silencing in vivo. The data, shown below, highlight that stereochemistry and PN chemistry can enhance the pharmacology of RNAi when applied to current state-of-art RNAi design.

Splicing - exon skipping

With PRISM, we have optimized stereopure oligonucleotides that promote efficient exon skipping in vitro and, ex vivo., and in vivo to restore protein production. In our exon-skipping programs, as with our other modalities, the sequence, chemistry and backbone stereochemistry of oligonucleotides impact their activity.

ToIn our Nucleic Acids Research paper (Kandasamy et al., 2022; doi: 10.1093/nar/gkac018), we highlight the impact of PN chemistry on exon skipping,skipping. In one application from the paper, we plotted the in vitro skipping efficiency of compounds containing PS / PO backbone chemistry modifications, depicted in the graph below by the teal dots, which are rank-ordered from left-to-right based on their exon-skipping potency in human myoblasts. The more potent molecules are shifted upwards as they are restoring expression. The navy dots represent the impact of a few stereopure PN modifications in compounds with otherwise identical sequences and 2’-ribose chemical modifications. There is an overall shift upwards in activity among the PS / PO / PN compounds, representing a substantial potency gain in most cases.

In a six-week study Moving in a double-knockout “dKO” mouse model, weekly doses of 75 mg / kg PN-containing compounds (shown belowvivo, we demonstrated successful exon-skipping in navy) or PS / PO modifications (shown below in light blue), were administered to assess the PK-PD relationship for both types of compounds. We foundmdx mice that the PN-containing compounds accumulated to higher levels in all muscle types comparedcorrelated with the PS / PO compounds (as shown below, top graphs). The PN-containing compounds alsodystrophin expression. PN-modified oligonucleotides led to more exon skipping (as shown below, middle graphs)exon-skipping and more dystrophin restoration (as shown below, bottom graphs)production in all muscles after six weeks of treatment, as shown below, but especially in the heart and diaphragm. These results demonstrate the impact of a few PN linkages – with no delivery vehicle or conjugate – significantly improves the PK-PD profiles for stereopure compounds.

Data adapted from Figure 5, Kandasamy et al., 2022; doi: 10.1093/nar/gkac018

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Editing - ADAR-mediated RNA editing

Most recently, we have applied our PRISM platform to the generation of short, single-stranded, highly specific A-to-I (G) RNA-editing oligonucleotides.oligonucleotides – called “AIMers”. Because our AIMers are relatively short and stable (fully chemically modified), we can leverage clinically proven GalNAc-mediated delivery to hepatocytes to further increase tissue uptake with subcutaneous dosing. We are developing fully chemically modified AIMers with and without GalNAc conjugation. In preclinical studies, we have evaluated thousands of oligonucleotides,AIMers, assessing a variety of sugar orand base modifications, backbone chemistry and stereochemistry, and other parameters such as oligonucleotideAIMer length to produce insight into the relationship between an oligonucleotide’sAIMer’s structure and its ability to elicit ADAR-editing activity.

With PRISM, we have generated stereopure antisense oligonucleotides,AIMers, optimized for chemistry and stereochemistry, thatwhich promote RNA editing with endogenous adenosine deaminase acting on RNA (ADAR) enzymes in cellular models. As shown in the figure below, we show the activity of beta-actin-editing stereopure oligonucleotides,AIMers, with and without PN linkages, compared to a matched stereorandom oligonucleotideAIMer (shown in black) in primary human hepatocytes. These oligonucleotidesAIMers are GalNAc conjugated to increase uptake in hepatocytes. The addition of PN chemistry substantially improves both potency and editing efficiency.

We have achieved efficient RNA editing in vitro with our oligonucleotidesAIMers across a variety of cell lines, including non-human primate and human primary hepatocytes, as shown in the figures below. We observed potent, dose-dependent RNA editing with three chemically distinct stereopure oligonucleotidesAIMers (ACTB 1, ACTB 2, ACTB 3) via GalNAc-mediated uptake.

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We next evaluated these same ACTB-editing AIMers ACTB-editing oligonucleotides in vivo in NHPs,non-human primates (“NHPs”), and the results are shown in the figures below. For this study, we dosed NHPs subcutaneously once a day for five days. We took liver biopsy samples at baseline at two days and 45 days after the last dose to evaluate editing. We detected up to 50% editing two days after the last dose as compared to a baseline of 0% editing, as shown in the figure below on the left. These editing results were durable: we continued to see significant editing 45 days after the last dose. The pharmacokinetic data, shown in the figure below onin the right,center, confirmed that a significant amount of oligonucleotideAIMer was still detectable in the liver at that time.

To evaluate the specificity of ADAR-editing oligonucleotides, we performed RNA-seq in primary human hepatocytes. In the figure below on the left, the total sequence coverage across the entire ACTB transcript for the mock-treated group (top) and oligonucleotide-treated samples (bottom) are shown. Editing was only detected at the targeted sequence in the actin transcript and the percentage of unedited “T” and edited “C” reads are indicated for each group.

To assess off-target editing for the whole transcriptome, a mutation-calling software was used to call edit sites. From this analysis, we observed nominal off-target editing across the transcriptome. Sites where potential off-target editing occurred mapped predominately to non-coding regions of the transcriptome, and had either low read coverage in the analysis or occurred at low percentages of less than 10%, indicating that these are relatively rare events, as shown in the figure below on the right.

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We intend to apply our RNA-editing modality to neurology, and we have assessedalso demonstrated efficient editing activity with unconjugated AIMers in vitro in both neurons and astrocytes. Our PN-containing stereopure molecules elicited efficient editing in both iCell neurons and iCell astrocytes, with EC50s for astrocytes reaching the 200 nM range in vitro as shown in the figures below. These potencies were obtained with chemical modifications to the oligonucleotides alone under free uptake conditions. There was no delivery vector and no conjugate used in these experiments.

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We have also evaluateddemonstrated potent (up to 65%) and durable (out to at least four months) editing activity with PN-containing stereopure oligonucleotides afterof UGP2 mRNA in vivo in multiple regions of the CNS following a single injection into the CNS ofAIMer dose in a proprietary humanized mouse model with human ADAR, as shown in the figure below.

We have also observed productive editing activity acrossbeyond liver and CNS with 50% or more editing activityunconjugated AIMers in many tissues. These results are preliminary findings evaluating editingmultiple tissue types including retina (below top right), kidney, liver, lung and heart of UGP2, a transcript that is more challenging to edit efficiently than ACTB.NHPs (below bottom left), and human PBMCs in vitro (below bottom right).

The application of PRISM to RNA editing opens the door to therapeutic applications extending beyond the restoration of protein function. We can use ADAR to upregulate protein expression, to modify protein function by altering post-translational modifications or protein-protein interactions, or to alter protein stability.  

To exemplify our ability to modulate protein-protein interactions using ADAR, we evaluated the well characterized KEAP1/NRF2 system. Through direct protein-protein interactions, KEAP1 negatively regulates the activity of NRF2 as an inducer of antioxidant gene expression. As a proof-of-concept experiment, we investigated if we could mimic the cellular stress response by using ADAR to edit individual amino acids at the protein-protein interaction interface between NRF2 and KEAP1 in vitro. If these edits work as designed, we would expect to see downstream activation of the NRF2-dependent gene expression program even in the absence of cellular stressors. As shown below, treatment with each AIMer resulted in increased expression of known downstream NRF2-dependent genes involved in the antioxidant response. Control treatment did not increase expression of any of the NRF2-dependent genes, indicating that AIMer treatment did not lead to NRF2-dependent gene expression changes through non-specific mechanisms such as increased cellular stress.

Therapeutic Programs

Our most advancedclinical-stage therapeutic programs areinclude two silencing programs for indications in neurology. We have ongoing clinical trialsthe CNS – WVE-004 for ALS / FTD and WVE-003 for HD – and a splicing program for protein restoration in muscle – WVE-N531 for DMD. In the third quarter of our two initial programs in HD (WVE-1201012022, we expect to select a development candidate and WVE-120102) and will initiate clinical trialsIND-enabling toxicology studies for a third program in HD (WVE-003), our C9orf72 program in ALS and FTD (WVE-004), and our exon 53 program in DMD (WVE-N531) in 2021. We continue to advance our ATXN3 program in SCA3. We are also pursuing additional CNS programs, including Alzheimer’s disease, Parkinson’s disease, and others, in collaboration with Takeda. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating ophthalmology programs and continue to explore additional targets in neurology andleveraging GalNAc-conjugated delivery for a hepatic disorders.indications – AATD.

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See below for more information on these programs and the diseases we are targeting.

Huntington’s Disease

Background and Market Opportunity

Huntington’s Disease (“HD”): HD is a rare hereditary neurodegenerative disease that results in early death and for which there is no cure. HD is caused by a mutation (i.e., an expanded CAG triplet repeat) in the HTT gene, which results in production of mutant HTT (“mHTT”) protein. In HD patients, there is a progressive loss of neurons in the brain leading to cognitive, psychiatric and motor disabilities. HD patients still possess wild-type (healthy) HTT (“wtHTT”) protein, which is important for neuronal function, and there is increasing evidence that wtHTT may be neuroprotective in an adult brain. Additionally, a dominant gain of function in mHTT protein and a concurrent loss of function of wtHTT protein may be important components of the pathophysiology of HD. Accordingly, suppression of wtHTT may have detrimental long-term consequences. A 2020 Nature publication (Poplawski, G.H.D., et al. Injured adult neurons regress to an embryonic transcriptional growth state. Nature 581, 77–82 (2020)) described results that involved conditional knockout of huntingtin in 4-month old mice (post-neuronal development), which demonstrated that huntingtin is at the center of the regeneration transcriptome and played an essential role in neural plasticity. In October 2019, at our Analyst and Investor Research Day, key opinion leaders in HD research presented data suggesting that wtHTT is neuroprotective in an adult brain; transport of key neurotrophic factors such as brain-derived neurotrophic factor (“BDNF”) are regulated by wtHTT levels; and HD may be caused by a dominant gain of function in mHTT and a loss of function of wtHTT protein. Further, the relative proportion of wtHTT to mHTT is critical based on evidence that suggests increased amount of wtHTT relative to mHTT may result in slower disease progression (measured by age-at-onset). Also, HD patients that lack wtHTT all together have significantly more severe disease, as measured by disease progression after symptom onset.

Symptoms of HD typically appear between the ages of 30 and 50 and worsen over the next 10 to 20 years. Many describe the symptoms of HD as similar to having amyotrophic lateral sclerosis, Parkinson’s Disease and Alzheimer’s Disease simultaneously. Patients experience a reduction in motor function and psychological disturbances. Life expectancy after symptom onset is approximately 20 years. In the most symptomatic stages, often lasting over 10 years, affected persons become fully dependent upon others to manage all activities of daily living; they lose the ability to make decisions, feed themselves and walk, often requiring premature placement in a long-term care facility. It is estimated that approximately 30,000 people in the United States have symptomatic HD. Our allele-selective approach may also enable us to address the pre-manifest, or asymptomatic, HD patient population in the future. More than 200,000 people in the United States are at-risk of developing HD.

Current Treatments

There are no approved treatments that can reverse or slow HD progression. Current pharmacological therapies only address HD symptoms. Antipsychotics are used to manage depression, irritability and chorea (involuntary movements). Xenazine (tetrabenazine) and Austedo (deutetrabenazine) are the only two therapies approved for the treatment of chorea associated with HD in the United States.

Our Programs

Our HD Portfolio: In HD, we are currently advancing three clinical programs. WVE-120101 and WVE-120102 are our first clinical programs in HD, where each is a distinct stereopure antisense oligonucleotide designed to selectively target a single nucleotide polymorphism (“SNP”) associated with the disease-causing mutant huntingtin (mHTT) mRNA transcript within the HTT gene: rs362307 (“mHTT SNP1”) and rs362331 (“mHTT SNP2”), respectively. Our third program in HD, WVE-003, is also a stereopure antisense oligonucleotide designed to target an undisclosed SNP3, “mHTT SNP3.” WVE-003 incorporates our novel PN backbone chemistry modifications, as well as learnings from the first two HD programs. We initiated clinical development of WVE-003 with the submission of a clinical trial application (“CTA”) in December 2020. Approximately 50% of the HD population carries SNP1 or SNP2, and, with overlap, up to 70% of the HD population carries SNP1, SNP2 or both. Approximately 40% of the HD population carries SNP3, and, with overlap, up to 80% of the HD population carries at least one of SNP1, SNP2 and/or SNP3. Targeting mRNAs with these SNPs allows us to lower expression of transcript from the mutant allele, while leaving the healthy transcript relatively intact. The healthy transcript is required to produce wtHTT protein which is important for neuronal function. We commonly refer to this method (or approach) as “allele-selective targeting.” SNPs are naturally occurring variations within a given genetic sequence and in certain instances can be used to distinguish between two related copies of a gene where only one is associated with the expression of a disease-causing protein. Our allele-selective approach may also enable us to address the pre-manifest, or asymptomatic, HD patient population in the future. We have shown that by targeting mHTT SNP1 and mHTT SNP2 in preclinical in vitro studies, the production of disease-causing proteins associated with HD can be selectively reduced. In addition, we have shown that by targeting mHTT SNP3 in preclinical in vitro studies, WVE-003 selectively reduces the expression of mHTT, and by targeting mHTT SNP3 in preclinical in vivo studies, WVE-003 demonstrated durable and potent knockdown of mHTT mRNA.

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For all three of our HD programs, we have demonstrated in vitro that these oligonucleotides preferentially target the mHTT transcript, while leaving the wtHTT mRNA largely intact in human neuronal systems. The ability of these oligonucleotides to reduce mHTT mRNA is dependent on the specific positioning of the Rp stereochemistry.

SNP Phasing Technology:To verify that HD patients have at least one of the SNPs that we are targeting on the mutant allele, we investigated multiple technologies that could provide highly accurate results and rapid turnaround. We conducted a prospective observational study of the frequency of SNP1 and SNP2 in patients with HD, which confirmed the feasibility of rapidly and prospectively identifying SNP1 and / or SNP2 in association with the mHTT allele in patients with HD. This study was published in Neurology Genetics in May 2020 and the manuscript is titled, “Genotyping single nucleotide polymorphisms for allele-selective therapy in Huntington’s disease.” In addition in October 2020, we summarized our SNP phasing methodology in a Molecular Therapy manuscript titled, “Investigational Assay for Haplotype Phasing of the Huntingtin Gene.” In 2019, we entered into an agreement with Asuragen, Inc. (“Asuragen”), a molecular diagnostics company, for the development and potential commercialization of companion diagnostics for our investigational WVE-120101 and WVE-120102 allele-selective therapeutic programs in HD. We have since expanded our agreement with Asuragen to enable us to use their scalable SNP phasing technology in our clinical trial for WVE-003.

Phase 1b/2a Clinical Trials: PRECISION-HD is a global clinical program consisting of the PRECISION-HD1 and PRECISION-HD2 clinical trials. PRECISION-HD1 and PRECISION-HD2 are two parallel, multicenter, double-blind, randomized, placebo-controlled Phase 1b/2a clinical trials evaluating WVE-120101 and WVE-120102, respectively, administered intrathecally, consisting of single-ascending dose and multiple-ascending dose portions. The primary objective of these two trials is to assess the safety and tolerability of intrathecal doses of WVE-120101 and WVE-120102, respectively, in early manifest HD patients. Additional objectives include measurement of total HTT protein and mHTT protein, and exploratory pharmacokinetic, pharmacodynamic, clinical and MRI endpoints. Each trial is designed with five multi-dose cohorts (2, 4, 8, 16, and 32 mg), each with 12 patients that have Stage I or Stage II HD, ages 25-65, who have screened positively for the presence of SNP1 or SNP2. Outside of the United States, we are conducting both the single-ascending dose and multiple-ascending dose portions of the PRECISION-HD1 and PRECISION-HD2 trials. In the United States, we received approvals to proceed with the single-dose portions of both trials. However, the FDA indicated to us that we cannot progress to the multiple-ascending dose portions of these trials in the United States unless we conduct an additional preclinical study and present the resulting data to the FDA for its review. For the single-dose portion of the PRECISION-HD1 trial in the United States, escalation to our highest proposed doses is subject to the FDA’s review and approval of additional monitoring plans. WVE-120101 and WVE-120102 have been granted orphan drug designation for the treatment of HD by the FDA.

PRECISION-HD2 trial:In December 2019, we announced initial clinical data from the ongoing PRECISION-HD2 trial. In an analysis comparing all patients treated with multiple intrathecal doses of WVE-120102 to placebo, a statistically significant reduction of 12.4% (p<0.05) in mHTT protein was observed in cerebrospinal fluid (“CSF”). An analysis to assess a dose response across treatment groups (2, 4, 8, or 16 mg) suggested a statistically significant response in mHTT reduction at the highest doses tested (p=0.03). WVE-120102 was generally safe and well tolerated across all cohorts. These topline data supported the addition of higher dose cohorts, and a 32 mg cohort was initiated in January 2020, which is fully enrolled. We expect to report biomarker and safety data from all cohorts of the PRECISION-HD2 trial, including all patients from the 32 mg cohort, at the end of the first quarter in 2021.

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PRECISION-HD1 trial: The PRECISION-HD1 trial is fully enrolled up to the 32 mg cohort. We expect to report biomarker and safety data from all completed cohorts up to and including the 16 mg cohort at the end of the first quarter in 2021.

Open-label Extensions of PRECISION-HD1 and PRECISION-HD2: In October 2019, we initiated an open-label extension (“OLE”) of the PRECISION-HD2 trial outside of the United States for patients who participated in that trial. In February 2020, we also initiated an OLE of the PRECISION-HD1 trial outside of the United States for patients who participated in that trial. Along with data from the PRECISION-HD1 and PRECISION-HD2 trials, we expect to report data from patients who have received multiple doses of 8 or 16 mg of WVE-120101 or WVE-120102 in the OLE portions of the trials at the end of the first quarter of 2021.

WVE-003 clinical trial: In December 2020, we initiated clinical development of WVE-003 with the submission of a CTA. We expect to initiate dosing in a Phase 1b/2a clinical trial of patients with HD in 2021.

Preclinical studies

WVE-120101 and WVE-120102: In our preclinical studies, as shown below, the stereopure oligonucleotide WVE-120101 (circles) or a stereorandom oligonucleotide (triangles) were bound to wtHTT or mHTT mRNA and incubated with human RNase H (left panel). WVE-120101 produced greater knockdown of mHTT compared with the stereorandom oligonucleotide. In addition, WVE-120101 was selective for mHTT over wtHTT, producing relatively little knockdown of wtHTT. The stereorandom oligonucleotide was not selective and knocked down both wtHTT and mHTT.

Using NHP serum, we analyzed the activation of the complement system following exposure to a panel of stereopure oligonucleotides and the parent stereorandom oligonucleotide, which were designed to target HTT. Each oligonucleotide was incubated at physiological temperature in NHP serum from three individual animals. Samples were removed at the indicated times, and complement activation was measured by the increase in C3a levels using the ELISA analytical method. As shown above (right panel), certain stereopure oligonucleotides and the stereorandom oligonucleotide demonstrated increased production of C3a; however, there was no production of C3a following exposure to WVE-120101, which also discriminated between wild-type and mutant HTT.

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WVE-120101 was tested for potency and selectivity of knocking down mHTT mRNA in a cellular reporter assay. WVE-120101 targeting the mHTT mRNA was co-transfected into HEK293 cells with two reporter plasmids: a plasmid with V5-tagged full-length HTT containing the U-variant SNP1 (mutant) and a plasmid with FLAG-tagged full-length HTT containing the C-variant SNP1 (wild-type). Knockdown of mHTT mRNA and mHTT protein was determined by quantitative reverse transcription PCR (RT-qPCR) and western blot analysis, respectively. All results were normalized to a non-specific stereorandom oligonucleotide as a control. As shown below, WVE-120101 potently reduced mHTT mRNA (left panel) and mHTT protein (right panel) and exhibited significant selectivity for mHTT at all doses tested. This study demonstrates the ability to knock down the mHTT allele while leaving the wtHTT (healthy) allele relatively unaffected.

Following these promising preclinical experiments, we investigated distribution characteristics of WVE-120101 in NHPs. Based on our preclinical studies, we believe stereochemistry enables improved protein binding and distribution. The figure below demonstrates meaningful distribution of WVE-120101 in an NHP study. In this preclinical study, we employed an in situ hybridization (“ISH”) ViewRNA assay. The ViewRNA assay provides us with the ability to stain oligonucleotides, allowing increased visibility and understanding of the distribution of WVE-120101 in the brain. As shown below, we found perinuclear and nuclear distribution of WVE-120101 (red) in NHP gray matter structures following intrathecal administration. The NHP ViewRNA assay demonstrated broad tissue distribution, including in the cortex and striatum. These findings are encouraging as we believe that distribution and penetration into several areas of the brain will be critical for the successful treatment of HD.

Preclinical studies on WVE-120102 showed similar results with regard to RNase H-mediated activity, mHTT allele specificity, and distribution in NHP brain.

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WVE-003: Using PRISM and our PN chemistry backbone modifications, we have designed WVE-003, an allele-selective stereopure oligonucleotide that specifically targets mHTT SNP3 on the mHTT mRNA while leaving wtHTT mRNA relatively intact in vitro. WVE-003 showed potent knockdown of mHTT mRNA in a preclinical study using induced pluripotent stem cell (iPSC)-derived motor neurons.

WVE-003 promoted RNase H–mediated degradation of mHTT RNA while sparing wtHTT RNA in a biochemical assay.

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We further demonstrated selectivity of WVE-003 in assays performed in induced pluripotent stem cell (iPSC) neurons from patients with HD that are heterozygous for SNP3. These cells are amenable to the free-uptake delivery method that is an integral part of PRISM. WVE-003 selectively silences the mutant transcript while largely sparing the wild-type transcript. By comparison, the pan-silencing active comparator silences both mutant and wild-type HTT transcripts.

We next tested our SNP3 compounds in vivo in a BACHD model for Huntington’s disease. This model expresses a mutant version of the human HTT gene. The model is homozygous for SNP3, so it is not suitable for assessing selectivity, but enables assessment of target engagement in vivo. Importantly, the model expresses multiple copies of the transgene; however, not all of the copies contain SNP3, so our SNP3 compounds cannot silence all the mHTT transcripts in these mice. After administration, WVE-003 showed significant mHTT mRNA knockdown compared with phosphate-buffered saline (PBS) at the highest concentration tested in the striatum and all but the lowest concentration tested in the cortex. WVE-003 showed comparable reduction of mHTT mRNA to that of the pan-silencing oligonucleotide, despite having fewer targets in these mice.

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In the cortex of BACHD mice, WVE-003 showed significant mHTT knockdown compared PBS through week 4. In the striatum, WVE-003 led to significant and durable mHTT knockdown that was sustained for 12 weeks, compared with PBS. WVE-003 led to significantly more knockdown than the pan-silencing reference compound at week 12. Since most but not all of the transgenes in this model contain SNP3, our SNP3 compounds are handicapped slightly versus the pan-silencing active comparator.

Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Hexanucleotide G4C2 expansions found in the C9orf72 gene are one of the most common genetic causes of the sporadic and inherited forms of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). Some patients exhibit characteristics of both ALS and FTD, indicating that these diseases form part of a continuum of neurological disease with some overlap in symptoms between them.

ALS Background and Market Opportunity

ALS is a neurodegenerative disease characterized by the progression and degeneration of motor neurons in the brain and spinal cord. Diagnosis may take up to 12 months and is made clinically by assessing the signs of upper and lower motor neuron degeneration in the same region of the body. Patients initially present with limb-onset disease (approximately 70% of patients), bulbar-onset disease (approximately 25% of patients) or with initial trunk or respiratory involvement (approximately 5% of patients). Age of onset is generally in the mid-to-late 50’s, and median survival is three years; however, up to 24% of patients survive for five to ten years. Survival in patients with C9orf72 ALS may be shorter than in patients with sporadic ALS.

In the United States and Europe combined, there are approximately three to five ALS patients per 100,000 people. This translates to approximately 13,000 diagnosed patients in the United States, although the total prevalence may be around 20,000 people in the United States. There are one or two newly diagnosed cases of ALS per year, per 100,000 people in the United States and Europe combined, resulting in approximately 5,000 newly diagnosed patients in the United States each year. While the majority of ALS cases are sporadic, approximately 10% of cases are found to be familial in nature. The C9orf72 gene mutation is currently the most common demonstrated mutation related to ALS and is present in approximately 40% of familial ALS and 8-10%8 – 10% of sporadic ALS patients.

ALS Current Treatments

There is significant unmet need for the treatment of ALS. Two medicines are currently approved in the United States for the treatment of ALS. Rilutek (riluzole), an inhibitor of glutamate release, was approved in 1995 for the treatment of patients with ALS. It was demonstrated to extend survival by three to six months. Radicava (edaravone) was approved in 2017 for the treatment of ALS. Administration of edaravone resulted in a significantly smaller decline in the ALS Functional RationRating Scale-Revised (ALSFRS-R)(“ALSFRS-R”) through six months of treatment as compared to placebo.

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FTD Background and Market Opportunity

FTD is a neurodegenerative disorder of the frontal and anterior temporal lobes of the brain. It is characterized by changes in personality, cognition (e.g., language impairment and executive dysfunction), and behavior (e.g., disinhibition, apathy and compulsivity). Diagnostic criteria categorize FTD into either the behavioral variant (approximately 60% of patients) or speech/language variant (approximately 40% of patients) based on the primary symptom observed at presentation; however, FTD results in dementia in all patients. The majority of FTD associated with the G4C2 expansion in the C9orf72 gene is categorized as the behavioral variant. FTD frequently has an onset in mid-life, and death typically occurs within three to 14 years of onset. FTD is the second most common form of early-onset dementia in people under the age of 65, after AD.

In FTD, the C9orf72 gene mutations appear in approximately 38% of familial cases and approximately 6% of sporadic cases. FTD affects approximately 55,000 people in the United States, of which 10 – 50% are familial cases and 50 – 90% are sporadic cases.

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FTD Current Treatments

There are currently no disease-modifying therapies approved for the treatment of FTD. Treatment to date has involved use of medications for symptomatic management.

Our Program

WVE-004: In ALS and FTD, we are advancing WVE-004, which uses our novel PN chemistry and preferentially targets the transcripts containing the hexanucleotide G4C2 expansion in the C9orf72C9orf72 gene. WVE-004 is designed to minimize the impact on normal C9orf72 protein in patients, thereby reducing potential on-target risk. In vitro, WVE-004 potently and selectively reduced V3 transcripts in iPSC-derived motor neurons, which were derived from a patient carrying a C9orf72-repeatC9orf72-repeat expansion. In C9 BAC transgenic mice, WVE-004 led to substantial reductions in repeat-containing C9orf72 transcripts and dipeptide repeat (DPR) proteins that are sustained for at least six months, without disrupting total C9orf72 protein expression.

WVE-004 clinical trial: InDecember 2020, we initiated clinical development of WVE-004 with the submission of a CTA. We expect to initiate dosing in aFOCUS-C9 Phase 1b/2a clinical trial: The FOCUS-C9 trial is a global, multicenter, randomized, double-blind, placebo-controlled Phase 1b/2a clinical trial to assess the safety and tolerability of bothintrathecal doses of WVE-004 for patients with C9-ALS and/or C9-FTD. Additional objectives include measurement of polyGP proteins in the cerebrospinal fluid (“CSF”), plasma and patientsCSF pharmacokinetics and exploratory biomarker and clinical endpoints. The FOCUS-C9 trial is designed to be adaptive with C9-FTDdose level and dosing frequency being guided by an independent committee. Preclinical models that have established pharmacologic activity have informed the starting dose for this trial. In July 2021, we announced the initiation of dosing in 2021.the FOCUS-C9 clinical trial. We expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry and enable decision making for WVE-004.

Expansion of the G4C2 repeat alters the normal expression of the C9orf72 gene and causes the production of repeat-containing RNAs. These RNAs accumulate in cellular nuclei in the form of RNA foci and can be translated into DPR proteins. Neuronal degeneration associated with the expression of the repeat expansion is hypothesized to arise either from a toxic loss-of-function mechanism due to a reduction in C9orf72 protein or a toxic RNA gain-of-function mechanism through the accumulation of RNA foci and/or DPRs in the brain and spinal cord.

In our Nature Communications paper (Liu, Y et al. Nat Comms. 2021), we report the discovery of a new targeting sequence that is common to all C9orf72 transcripts but enables preferential knockdown of repeat-containing transcripts in multiples models and C9BAC transgenic mice. Wild-type C9orf72 alleles produce three mRNA transcripts: variant 1 (V1), variant (V2), and variant (V3). We apply our platform to generate stereopure oligonucleotides that target a sequence at the exon 1b-intron 1 junction, termed Splice Site-1b (“SS1b”), that is common to all C9orf72C9orf72 transcripts (shown below in “b”, pre-mRNAs corresponding to V1-V3 are illustrated; the coral star indicates SS1b). In multiple in vitro model systems, an unoptimized stereopure oligonucleotide yields preferential knockdown of exon1a-containing transcripts. The Nature Communications paper describes our work to identify and validate the targeting site to achieve variant-selective knockdown of expansion-containing C9orf72 transcripts. The publication highlights the foundational work that led to the development of our clinical candidate.

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By targeting the V1 and V3 mRNA transcripts that contain the G4C2 expansion and sparing V2 transcripts and healthy C9orf72 protein, WVE-004 has the potential to reduce both RNA-based and protein-based toxicity, thereby impacting the disease course and slowing the progression of ALS or FTD.

In vitro, WVE-004 potently and selectively reduced V3 transcripts in iPSC-derived motor neurons, which were derived from a patient carrying a C9orf72 repeat expansion.

WVE-004 led to dose-dependent knockdown of V3 transcripts and DPRs in mouse spinal cord tissue. In the transgenic model, mice express the human C9orf72 repeat-containing gene from a bacterial artificial chromosome (“BAC”) insertion. We observed qualitatively similar dose-dependent knockdown of V3 transcripts and the polyGP DPR protein in mouse cortex tissue (data not shown).

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In C9 BAC transgenic mice, WVE-004 led to substantial reductions in repeat-containing C9orf72 transcripts and dipeptide repeat (DPR) proteins that are sustained for at least six months, without disrupting total protein expression.

Huntington’s Disease

Background and Market Opportunity

Huntington’s Disease (“HD”): HD is a rare hereditary neurodegenerative disease that results in early death and for which there is no cure. In HD patients, there is a progressive loss of neurons in the brain leading to cognitive, psychiatric and motor disabilities. HD is caused by a defect (i.e., an expanded CAG triplet repeat) in the HTT gene, which results in production of mutant HTT (“mHTT”) protein. HD patients still possess some wild-type (healthy) HTT (“wtHTT”) protein, which is important for neuronal function and which may be neuroprotective in an adult brain. Studies suggest a dominant gain of function in mHTT protein and a concurrent loss of function of wtHTT protein may be important components of the pathophysiology of HD. Accordingly, therapeutic approaches for HD that involve suppression of wtHTT may have detrimental long-term consequences. There is growing evidence of the importance of wtHTT, including a 2020 Nature publication (Poplawski, G.H.D., et al. Injured adult neurons regress to an embryonic transcriptional growth state. Nature 581, 77–82 (2020)) which evaluated conditional knockout of huntingtin in 4-month old mice (post-neuronal development) and demonstrated that huntingtin is at the center of the regeneration transcriptome and plays an essential role in neural plasticity. In addition, at our Analyst and Investor Research Day in October 2019, key opinion leaders in HD research presented data suggesting that wtHTT is neuroprotective in an adult brain; transport of key neurotrophic factors such as brain-derived neurotrophic factor (“BDNF”) is regulated by wtHTT levels; and HD may be caused by a dominant gain of function in mHTT and a loss of function of wtHTT protein. Further, the relative proportion of wtHTT to mHTT may be critical based on evidence that suggests increased amount of wtHTT relative to mHTT may result in slower disease progression (measured by age-at-onset).

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Symptoms of HD typically appear between the ages of 30 and 50 and worsen over the next 10 to 20 years. Many describe the symptoms of HD as similar to having amyotrophic lateral sclerosis, Parkinson’s Disease and Alzheimer’s Disease simultaneously. Patients experience a reduction in motor function and psychological disturbances. Life expectancy after symptom onset is approximately 20 years. In the most symptomatic stages, often lasting over 10 years, affected persons become fully dependent upon others to manage all activities of daily living; they lose the ability to make decisions, feed themselves and walk, and often require premature placement in a long-term care facility. It is estimated that approximately 30,000 people in the United States have symptomatic HD. Our allele-selective approach may also enable us to address the pre-manifest, or asymptomatic, HD patient population in the future. More than 200,000 people in the United States are at-risk of developing HD.

Current Treatments

There are no approved treatments that can reverse or slow HD progression. Current pharmacological therapies only address HD symptoms. Antipsychotics are used to manage depression, irritability and chorea (involuntary movements). Xenazine (tetrabenazine) and Austedo (deutetrabenazine) are the only two therapies approved for the treatment of chorea associated with HD in the United States.

Our Programs

WVE-003: In HD, we are currently advancing WVE-003, a stereopure antisense oligonucleotide designed to selectively target an undisclosed single nucleotide polymorphism (“SNP”), “mHTT SNP3”, associated with the disease-causing mutant huntingtin (“mHTT”) mRNA transcript within the HTT gene. SNPs are naturally occurring variations within a given genetic sequence and in certain instances can be used to distinguish between two related copies of a gene where only one is associated with the expression of a disease-causing protein. Approximately 40% of the HD population carries SNP3 according to published literature (Carroll et al., Molecular Therapy, 2011). WVE-003 incorporates our novel PN chemistry, as well as learnings from our first-generation HD programs. Targeting mRNA with SNP3 allows us to lower expression of transcript from the mutant allele, while leaving the healthy transcript relatively intact. The healthy transcript is required to produce wtHTT protein which is important for neuronal function. We commonly refer to this method (or approach) as “allele-selective targeting.” Our allele-selective approach may also enable us to address the pre-manifest, or asymptomatic, HD patient population in the future. In preclinical studies, WVE-003 showed dose-dependent and selective reduction of mHTT mRNA in vitro, potent and durable knockdown of mHTT mRNA and protein in vivo. A pharmacokinetic-pharmacodynamic (PK-PD) model for WVE-003 based on preclinical data predicts that WVE-003 may attain sufficient concentrations to engage mHTT transcript in both the cortex and striatum and decrease expression of mHTT protein.

SNP Phasing Technology:To verify that HD patients have a SNP selectively available on the mutant allele, we investigated multiple technologies that could provide highly accurate results and rapid turnaround. We conducted a prospective observational study of the frequency of two SNPs in patients with HD, which confirmed the feasibility of rapidly and prospectively identifying SNPs in association with the mHTT allele in patients with HD (Claassen et al., Neurol Genet 2020; Svrzikapa et al., Molecular Therapy 2020). We have an agreement with Asuragen, Inc. (“Asuragen”), a molecular diagnostics company that was acquired by Bio-Techne Corporation on April 6, 2021, for the development and potential commercialization of companion diagnostics for our allele-selective therapeutic program in HD. This agreement includes the use of their scalable SNP phasing technology (AmplideX^®  HTT SNP/Repeat Phasing Clinical Trial Assay) in our SELECT-HD trial for WVE-003.

SELECT-HD Phase 1b/2a clinical trial:  The SELECT-HD trial is a multicenter, randomized, double-blind, placebo-controlled Phase 1b/2a trial to assess the safety and tolerability of intrathecally administered WVE-003 for patients with early manifest HD. Additional objectives include measurement of mHTT and wtHTT protein and exploratory pharmacokinetic, pharmacodynamic, clinical and MRI endpoints. The SELECT-HD trial is designed to be adaptive, with dose level and dosing frequency being guided by an independent committee. Preclinical models that have established pharmacologic activity have informed the starting dose for this trial. In September 2021, we announced the initiation of dosing in the SELECT-HD clinical trial. We expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry and enable decision making for WVE-003.

Preclinical studies

WVE-003 showed potent knockdown of HTT mRNA in a preclinical study using induced pluripotent stem cell (“iPSC”)-derived motor neurons homozygous for SNP3 (as shown below).

WVE-003 promoted RNase H–mediated degradation of mHTT RNA while sparing wtHTT RNA in a biochemical assay.

We further demonstrated selectivity of WVE-003 in assays performed in induced pluripotent stem cell (iPSC) neurons from patients with HD that are heterozygous for SNP3. These cells are amenable to the free-uptake delivery method that is an integral part of PRISM. WVE-003 selectively silences the mutant transcript while largely sparing the wild-type transcript. By comparison, the pan-silencing active comparator silences both mutant and wild-type HTT transcripts.

We next tested our SNP3 compounds in vivo in a BACHD model for Huntington’s disease. This model expresses a mutant version of the human HTT gene. The model is homozygous for SNP3, so it is not suitable for assessing selectivity, but enables assessment of target engagement in vivo. Importantly, the model expresses multiple copies of the transgene; however, not all of the copies contain SNP3, so our SNP3 compounds cannot silence all the mHTT transcripts in these mice. After administration, WVE-003 showed significant mHTT mRNA knockdown compared with phosphate-buffered saline (PBS) at the highest concentration tested in the striatum and all but the lowest concentration tested in the cortex. WVE-003 showed comparable reduction of mHTT mRNA to that of the pan-silencing oligonucleotide, despite having fewer targets in these mice.

In the cortex of BACHD mice, WVE-003 showed significant mHTT knockdown compared PBS through week 4. In the striatum, WVE-003 led to significant and durable mHTT knockdown that was sustained for 12 weeks, compared with PBS. WVE-003 led to significantly more knockdown than the pan-silencing reference compound at week 12. Since most but not all of the transgenes in this model contain SNP3, our SNP3 compounds are handicapped slightly versus the pan-silencing active comparator.

In vivo allele-selectivity:Using an allele-selective mHTT SNP3 targeting oligonucleotide that represented a back-up candidate to our WVE-003 clinical candidate, we investigated allele-selectivity in vivo. After administration (3 x 100 ug ICV doses), the allele-selective molecule decreased mHTT and spared wtHTT in the cortex, striatum and hippocampus of Hu97/18 mice up to 12 weeks post-injection throughout the brain. By contrast a pan-silencing control decreased expression of both mHTT and wtHTT, and the silencing activity was both less potent and less durable than the allele-selective molecule, especially in the striatum.

Data are mean ± SD, n=8; Stats: ns non-significant, *P<0.05, **P<0.01, ***P<0.0001, ****P<0.0001 versus PBS by 1-way ANOVA

Spinocerebellar ataxia 3

Background and Market Opportunity

SCA3 is a rare, hereditary (autosomal dominant) progressive neurodegenerative disorder that results in a lack of muscle control and coordination of the upper and lower extremities. Signs and symptoms of SCA3 may begin between childhood and late adulthood, and they vary greatly. Symptoms may include progressive clumsiness in the arms and legs, spasticity, difficulty with gait, and impaired speaking, swallowing and eye movements. Symptoms of the disease worsen over time, eventually leading to paralysis. Some patients

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with SCA3 develop dystonia or symptoms similar to those of PD, including twitching of the face or tongue, and nerve damage (neuropathy). Life expectancy ranges from the mid-30s in the more severe forms, to a nearly normal life expectancy for those with milder forms of the disease.

SCA3 is caused by a CAG-repeat expansion in the ATXN3 gene, resulting in an abnormally long polyglutamine stretch in the encoded ataxin-3 protein. Mutant ataxin-3 protein is thought to cause widespread neuronal loss in the brain and spinal cord, likely through a toxic gain-of-function mechanism. SCA3 is the most common dominantly inherited form of ataxia. The prevalence of SCA3 is believed to be one to two cases in 100,000 people with significant geographic and ethnic variations.

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Current Treatments

There are currently no disease-modifying therapies approved for treatment of SCA3. Treatment to date has involved the use of medications for symptomatic management.management, as well as physical and occupational therapy.

Our Program

In SCA3, we are continuing to advance our program targeting ATXN3.

Duchenne Muscular Dystrophy

Background and Market Opportunity

DMD is a rare, genetic progressive neuromuscular disorder caused by mutations in the dystrophin gene on the X chromosome that affects approximately one in 5,000 newborn boys around the world (approximately 20,000 new cases annually). The dystrophin protein is part of a protein complex called the dystrophin-associated protein complex that acts as an anchor, connecting each muscle cell’s structural framework with a lattice of proteins and other molecules outside the cell through the muscle cell membrane. The dystrophin-associated protein complex protects the muscle from injury during contraction and relaxation. Patients with DMD typically develop muscle weakness in the early years of life and become wheelchair-bound in their early teens. As the disease progresses, DMD patients typically develop respiratory, orthopedic and cardiac complications. Cardiomyopathy and breathing difficulties usually begin by the age of 20, and few individuals with DMD live beyond their thirties.

Current Treatments

While there are approved therapies for DMD, there is no cure, and there continues to be significant unmet medical need. In most countries, corticosteroids are the standard drug therapy, which slows the progression of muscle weakness and delays loss of ambulation by two to three years. In February 2017, the FDA approved Emflaza (deflazacort), became the first corticosteroid approved as a treatment in the United States approved by the FDA as a treatment for DMD patients older than five years of age.

In 2016, Sarepta Therapeutics’ Exondys 51™ (eteplirsen) received accelerated approval in the United States for the treatment of patients with DMD, who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping. In 2019, Sarepta Therapeutics’ Vyondys 53™ (golodirsen)Two drugs have received accelerated approval in the United States for the treatment ofDMD patients with DMD who have a confirmed mutation of the dystrophin gene amenable to exon 53 skipping. Additionally,skipping: Sarepta Therapeutics’ Vyondys 53™ (golodirsen) in 2020, the FDA granted accelerated approval to2019 and NS Pharma’s Viltepso™ (viltolarsen) for DMD patients with a mutation amenable to exon 53 skipping.in 2020. NS Pharma has also received Marketing Authorization for Viltepso in Japan. In 2021, Sarepta’s Amondys 45™ (casimersen) received accelerated approval for DMD patients with a mutation amenable to exon 45 skipping. According to U.S. accelerated approval guidelines, approval is based on a surrogate endpoint that is likely to predict clinical benefit, but no clinical benefit needs to be established at the time of FDA approval, and noapproval. No clinical benefit of has yet been established for eteplirsen, golodirsen, viltolarsen, or vitolarsen.casimersen. Thus, in accordance with the U.S. accelerated approval regulations, the FDA is requiring Sarepta to conduct clinical trials to verify and describe the clinical benefit of eteplirsen, golodirsen, and is requiringcasimersen.  Similarly, NS Pharma is required to conduct a clinical trial to verify and describe the clinical benefit of viltolarsen. If any of these confirmatory trials fail to verify clinical benefit, the FDA could initiate proceedings to withdraw approval of the respective drug.drug(s).

In 2014, PTC Therapeutics’ Translarna™ (ataluren) was the first disease-modifying treatment to receive conditional approval by the EMA for the treatment of ambulatory DMD patients over 5 years of age who have a nonsense mutation (12% of DMD cases) in the dystrophin gene. In 2016, the EMA did not allow atalurenTranslarna to convert to full marketing authorization,authorization; rather, it granted a renewal of the conditional approval. In 2018, EMA expanded the conditional approval for Translarna to include treatment of ambulatory DMD patients ≤2 years of age who have a nonsense mutation in the dystrophin gene. In June 2020, the EMA removed a statement from the SmPCsummary of product characteristics (“SmPC”) for Translarna that “efficacy has not been demonstrated in non-ambulatory patients.”

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Our Program

WVE-N531: In DMD, we are advancing WVE-N531, which is designed to target exon 53 within the dystrophin gene. WVE-N531 is designed to cause the cellular splicing machinery to skip over this exon during pre-mRNA processing, which restores the dystrophin mRNA reading frame and enables production of truncated, but functional dystrophin protein. Exon-skipping produces dystrophin from the endogenous dystrophin gene (not micro or mini dystrophin expressed from a vector), under the control of native gene-regulatory elements, resulting in normal temporospatial expression. WVE-N531 will beis both our first splicing candidate and our first systemically administered candidate incorporating PN backbone chemistry modifications to be assessed in the clinic.

WVE-N531 clinical trial: In September 2021, we announced the initiation of dosing in an open-label clinical trial evaluating WVE-N531 as a treatment for boys with DMD who are amenable to exon 53 skipping. We expect to submit a CTAshare clinical data, including muscle biopsies, in 2022 to provide insight into the clinical effects of PN chemistry and enable decision making for WVE-N531 by the end of the first quarter in 2021.WVE-N531.

Preclinical data

In vitro, WVE-N531 induced dose-dependent exon 53 skipping up to 49% and dystrophin protein restoration up to 71% in DMD patient-derived myoblasts carrying a deletion of exons 45-52. In these experiments, cells were exposed to WVE-N531 at 0.1 µM-10 µM under gymnotic conditions. After four days of oligonucleotide treatment, efficiency at skipping exon 53 was determined by

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quantitative RT-PCR. After six days of oligonucleotide treatment, protein lysate was analyzed by western blot for dystrophin protein expression.

To understand the effects of PN backbone chemistry modifications in vivo, we conducted a study in a double-knockout or “dKO” mouse model, which has a mutation in exon 23 leading to a lack of dystrophin, as well as a mutation leading to a lack of utrophin. We compared the effects of a PS/PO-containing molecule dosed at 150 mg/kg weekly to a PN-containing compound dosed at the same level, a PN-containing compound at 75 mg/kg every other week and a control group dosed with PBS. Other than the placement of the three PN backbone linkages, these molecules have the same sequence and chemistry. There is a significant increase in survival in those animals treated with PN containing compounds as compared with the other treatment groups. As shown in the figure below on the left, both cohorts of mice receiving the PN-containing molecules (shown in dark blue and light green) had 100% survival at the time of study termination, with a median age of approximately 40 weeks. By comparison, the median survival for the mice receiving the PS/PO-containing molecule dosed at 150 mg/kg weekly was approximately 12 weeks and the dKO control animals that received PBS had a median survival of approximately seven weeks.  These results were published in Nucleic Acids Research (Kandasamy et al., 2022; doi: 101.1093/nar/gkac018).

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Alpha-1 Antitrypsin Deficiency

Background and Market Opportunity

We are leveraging our ADAR editing platform capability to develop a potentially novel treatment for alpha-1 antitrypsin deficiency (“AATD”). AATD is a rare, inherited genetic disorder that is commonly caused by a G-to-A point mutation in the Z allele of the SERPINA1 gene.gene; this mutant allele is termed the Z allele. This mutation leads to misfolding and aggregation of alpha-1 antitrypsin (“AAT”) protein in hepatocytes and a lack of functional AAT in the lungs. People with AATD typically exhibit progressive lung damage, liver damage or both, leading to frequent hospitalizations and potentially terminal lung disease and/or liver disease. While the few approved therapies for AATD modestly increase circulating levels of AAT in those with the lung pathology, there are no approved therapies to address the liver pathology. Approximately 200,000 people in the United States and Europe are homozygous for the Z allele, which is the most common form of severe disease.

Current Treatments

There are five treatments currently approved in the United States for chronic augmentation and maintenance therapy in adults with emphysema due to congenital deficiency of alpha1-proteinase inhibitor (Alpha1-PI). Per FDA labeling for each, the effect of augmentation therapy with any alpha1-proteinase inhibitor on pulmonary exacerbations and on the progression of emphysema in Alpha1-PI deficiency has not been demonstrated in randomized, controlled clinical trials. Patients with AATD can also be treated with therapies used in other lung diseases including bronchodilators to open airways and corticosteroids to reduce chronic inflammation common in the lungs of AATD patients.

There are currently no approved therapies to prevent the accumulation of the mis-foldedmisfolded AAT protein in the liver. Treatments are available to help deal with intestinal bleeding, fluid in the abdomen, nutritional issues and other complications from scarring of the liver, but ultimately many patients will progress towards requiring a liver transplant.

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Our Program

In November 2020, we announced thatOur AATD program is the first to leverage our first ADAR editing program would be for AATD. Our novel RNA editing platform capability that uses GalNAc-conjugated AIMers (RNA base editing oligonucleotides) and endogenous ADAR enzymes of A-to-I (G)by correcting a single base editing oligonucleotides, making this a potentially best-in-class modality for correctingin the G-to-A disease-causing mutation in mRNA coded by the mutant SERPINA1 Z allele. By correcting the single RNA base mutation, mRNA. ADAR editing may provide an ideal approach for increasing circulating levels of wild-type AAT protein and reducing aggregation in the liver, thus simultaneously addressing both the lung and liver manifestations of the disease. We expect to select an AATD AIMer development candidate and initiate IND-enabling toxicology studies in the third quarter of 2022.

Preclinical data

In a primary hepatocyte SERPINA1 Z allele cell model, we demonstrated that editing the Z allele mRNA restored protein secretion from hepatocytes, as shown in the figure below. We observed upwards of 60% correction of the Z allele mRNA back to wild-type transcript (left)(as shown below on the left), which prevented protein misfolding and increases secretion of editing AAT protein from hepatocytes (right)(as shown below on the right). Edited, wild-type AAT protein was confirmed to be wild-type by mass spectrometry and the function of secreted, edited AAT protein was confirmed by neutrophil elastase inhibition assay. We expect to deliver

With a GalNAc-AIMer (specifically “SA1-4”) dosed at 3 x 10 mg/kg, we reported proof-of-concept preclinical in vivo data supportingthat demonstrated up to 40% editing of human SERPINA1 Z allele mRNA in liver at an initial time point, which resulted in a therapeutically meaningful increase in circulating, functional wild-type AAT protein (as shown in the continued developmenttwo charts below). This initial in vivo study utilized our proprietary transgenic mouse model, which has both the human SERPINA1 Z-allele, as well as human ADAR that is expressed comparably to human cells.

To evaluate the specificity of our AATD programGalNAc-AIMer (specifically “SA1-4 AIMer”), we performed RNA-seq on liver biopsies from treated animals. The figure below on the left shows total sequence coverage across the entire SERPINA1 transcript for the AIMer-treated samples. The percentage of unedited “T” and edited “C” reads are indicated for each group. Editing is only detected at the intended, on-target sequence in the first halfSERPINA1 transcript. Thus, the protein being produced using this approach is truly wild-type M-AAT protein. This also confirms there is no editing of 2021.bystander residues, as has been seen with DNA targeting approaches. To assess off-target editing for the whole transcriptome, we applied a mutation-calling software to search edit sites. From this analysis, we observed minimal off-target editing across the transcriptome. Sites where potential off-target editing occurred had either low read coverage in the analysis or occurred at low percentages of less than 10%, indicating that these are rare events, as shown below on the right. In both analyses, we find a high percentage of editing that is specific for the target site in the SERPINA1 transcript.

Using an optimized AIMer (specifically “SA1-5”), we demonstrated restoration of functional AAT protein in a transgenic mouse model with bi-weekly doses of 10 mg/kg following initial loading doses. At 19 weeks, AIMer treatment resulted in approximately 60% RNA editing of SERPINA1 transcript and circulating serum AAT levels (18.5 uM) in AIMer treated mice that were approximately 5-fold greater than PBS-treated control (as shown below).

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Ophthalmology

In ophthalmology, we have generated in vitro, ex vivo and in vivo data in preclinical studies that support the potential of our stereopure oligonucleotides for the treatment of rare, inherited eye diseases. Our preclinical data demonstrate that a single intravitreal injection of stereopure oligonucleotide in the eye of non-human primates (“NHPs”) resulted in greater than 95% knockdown of a target RNA in the retina for at least 4 months. Based on these data,months, which supports the potential to our goal is to design candidates that could achieve a therapeutic effect with only two doses per year. We have also used AIMers to achieve up to 50% mRNA editing of UGP2 in the posterior of mouse eyes following a single intravitreal dose. Our pipeline includes two preclinical programs: Usher syndrome type 2A (“USH2A”) and retinitis pigmentosa due to a P23H mutation in the RHO gene (“RhoP23H”). In September 2020, we presented in vitro,ex vivo, and in vivo preclinical data on our USH2A program, which is designed to promote USH2A exon 13 skipping, and we presented in vitro and in vivo data on our RhoP23H program, which is designed to selectively silence RhoP23H transcripts. We also presented results from our first achievement of ADAR editing in NHP retina ex vivo using stereopure oligonucleotides.

We believe PRISM affords us a unique opportunity to address these challenging inherited retinal diseases. Oligonucleotides developed based on PRISM demonstrate superior potency and durability as compared to stereorandom oligonucleotides and are optimized to minimize immune activity and can yield selective activity against closely related sequences.

We have demonstrated with preclinical, proof of concept studies with oligonucleotides targeting Malat1 that our stereopure compounds exhibit these desirable properties specifically in the eye. These studies (see below) supported our decision to develop therapeutic candidates with the potential to be potently and durably active, which would allow for less frequent administration via intravitreal (“IVT”) injection and would give us an advantage over molecules delivered via subretinal injection or that are less potent and require frequent IVT injection.

Our discovery research has tested the hypothesis that controlling the chirality of PS linkages in the backbones of oligonucleotides will provide a benefit in potency, tissue distribution and duration of effect in the eye. In these studies, we have employed Malat1 as a surrogate target. Previously, we generated stereopure compounds targeting Malat1, a nuclear-enriched, long non-coding RNA and evaluated them in vitro in iCell neurons under gymnotic conditions. Our best-performing compounds exhibited IC₅₀ values approximately 24-fold lower than those of stereorandom oligonucleotides of comparable sequence and chemistry. PRISM optimization with PN chemistry resulted in identification of compounds that exhibit a further 8-fold shift in IC₅₀in vitro under gymnotic conditions. We then evaluated the optimized stereopure oligonucleotides in vivo following a single IVT injection (50 µg) in the mouse eye. We assessed expression of Malat1 RNA by qPCR over a nine-month period. In the posterior of the eye (retina, choroid, sclera), a single 50 µg IVT injection of stereopure ASO with PN linkages (shown in navy) led to 50% knockdown of Malat1 that persisted for up to nine months (shown in the figure below). The incorporation of a few PN linkages resulted in substantial durability benefits.

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In our Translational vision science & technology paper (Byrne M, et al. Trans Vis Sci Tech. 2021;10(1):23), we describe an optimized stereopure antisense oligonucleotide, MALAT1-200, that shows enhanced potency, efficacy, and durability of MALAT1 RNA depletion in the eye compared with its stereorandom counterpart, MALAT1-181, in mouse and NHP eyes via IVT injection (see section ‘PRISM: Our proprietary discovery and drug development platform’). After validating the efficacy and durability of the stereopure oligonucleotide in NHP eyes, we tested its activity in ex vivo cultures of human retinal tissue from donor eyes (as shown below in “A”). Retinal tissue samples were treated with vehicle, stereorandom MALAT1-181 (0.3, 1, and 3 μM), or stereopure oligonucleotide MALAT1- 200 (0.3, 1, and 3 μM) under gymnotic conditions for 48 hours. Overall, there was an effect of treatment independent of dose (P < 0.001), an effect of dose independent of treatment (P < 0.001), and an effect of treatment at each dose (P < 0.001, three-way ANOVA). At 0.3- and 1-μM doses, stereopure oligonucleotide was more active than stereorandom oligonucleotide, leading to a significantly larger decrease in the percentage of remaining MALAT1 RNA expression (0.3 μM: 44.7% vs. 60.7%, P < 0.001; 1 μM: 35.3% vs. 55.4%, P < 0.001). In addition, 0.3 μM of stereopure oligonucleotide led to a significantly larger decrease in the percentage of MALAT1 RNA expression versus 1 μM of stereorandom oligonucleotide (P < 0.05). At 1 μM, activity of the stereopure oligonucleotide matched activity observed with 3 μM of stereorandom oligonucleotide (P > 0.05), indicating the potency and efficacy benefit with stereopure oligonucleotide detected in mice may translate to humans (as shown below in “B”).

These preclinical studies support the hypothesis that stereopure compounds can be designed to increase the potency, tissue distribution and duration of effect in the eye compared with stereorandom oligonucleotides.

USH2A program: Usher syndrome type 2A is an autosomal recessive disease characterized by hearing loss at birth and progressive vision loss beginning in adolescence or adulthood. It is commonly caused by a mutation that introduces a stop codon and prevents translation of usherin protein, leading to progressive degeneration of photoreceptors. Antisense oligonucleotides that preferentially promote exon skipping may restore production of functional usherin protein and potentially confer therapeutic benefit in patients.

In 2020, at TIDES: Oligonucleotides and Peptide Therapeutics, we presented our preclinical USH2A data. To evaluate potency,

Using a stereopure antisense oligonucleotide, targeting USH2A (Compound 1) and a stereorandom reference antisense oligonucleotide (ASO) described in WO2018055134A1 were added to Y79 cells under free-uptake conditions, and exon-skipping was evaluated by qPCR.

As shown above, a stereopure antisense oligonucleotide (light blue)we induced dose-dependent USH2A exon skipping that was 2-fold more potent than a stereorandom reference ASO under gymnotic conditions in Y79 cells.

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Ex vivo approaches enable us to investigate the activity of stereopure antisense oligonucleotides under gymnotic conditions in NHP eyes and To bridge the gap between in vitro and in vivo studies. As shown above, studies, we used a stereopure antisense oligonucleotide (light blue) inducedto induce dose-dependent USH2AUSH2A exon skipping in thea NHP retina ex vivo under gymnotic conditions 48 hours after treatment.

Moving in vivo, as shown above, Finally, we used a stereopure oligonucleotide elicitedto demonstrate dose-dependent exon-skipping in NHP retina.retina in vivo.

Retinitis pigmentosa (RP) program: Retinitis pigmentosa is a group of rare, genetic eye disorders resulting in progressive photoreceptor cell death and gradual loss of function. Currently, there is no cure for this condition. Approximately 10% of U.S. autosomal dominant RP cases are caused by the P23H mutation in the rhodopsin gene (RHO). Mutant P23H rhodopsin protein is thought to misfold and co-aggregate with wild-type rhodopsin, resulting in a gain-of-function or dominant negative effect in rod photoreceptor cells.

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A luciferase reporter assay was developed to evaluate the ability to selectively reduce mutant RhoP23H transcript while maintaining wild-type transcript. An allele-selective stereopure sequence identified with PRISM as well as a stereorandom sequence described in WO2016138353A1 and luciferase reporter plasmids (wild-type and mutant rhodopsin) are transfected into Cos7 cells. 48-hours later, cells were harvested, and relative luminescence was measured.

As shown above,We have presented preclinical data demonstrating dose-dependent reduction of mutant and wild-type Rhodopsin transcripts resulted from treatment with the reference stereorandom molecule (left side figure). However, dose-dependent reduction of only the mutant RhoP23H transcript occurred following treatment with our stereopure, allele-selective sequence, (middle figure). In a surrogate with preservation of wild-type Rhodopsin transcripts.

At the 2021 Oligonucleotide Therapeutics Conference, we shared the first in vivo system (top right figure), stereopure oligonucleotides targeting the mouse P23H mutation reduced the target data, which was performed by our collaborator at University of Louisville, to show functional benefit after treatment with our RhoP23H candidate in a dose dependent manner 1 week post single IVT injection providing proof of concept data for targeting this mutation severe humanized pig model. PN-containing oligonucleotides preserve retinal cell morphology, prevent rod cell death and restore rod cell function in vivo. Utilizing asevere humanized pig model carrying the human P23H mutation, our allele-selective stereopure oligonucleotide reduced human P23H RNA expression 2-weeks post single IVT.  of adRP.

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Licensing Arrangements and Research Collaborations

Our business strategy is to develop and commercialize a broad pipeline of novel nucleic acid therapies. As part of this strategy, we have entered into, and may enter into new partnership and collaboration agreements as a means of advancing our own nucleic acid therapeutic programs, investing in third-party technologies to further strengthen PRISM and leveraging external partnerships to extend the reach of PRISM into therapeutic areas where our platform demonstrates a competitive advantage.

Our Partnerships

Takeda

In February 2018, Wave Life Sciences USA, Inc. (“Wave USA”) and Wave Life Sciences UK Limited (“Wave UK”) entered into a collaboration and license agreement (the “Takeda Collaboration Agreement”) for a global strategic collaboration (the “Takeda Collaboration”) with Takeda Pharmaceutical Company Limited (“Takeda”), pursuant to which Wave USA, Wave UK and Takeda agreed to collaborate on the research, development and commercialization of oligonucleotide therapeutics for disorders of the Central Nervous System (“CNS”). The Takeda Collaboration provides Waveprovided us with at least $230.0 million in committed cash and Takeda with the option to co-develop and co-commercialize Wave’sour CNS development programs in (1) Huntington’s disease (“HD”); (2) amyotrophic lateral sclerosis (“ALS”) and frontotemporal dementia (“FTD”); and (3) Wave’sour discovery-stage program targeting ATXN3 for the treatment of spinocerebellar ataxia 3 (“SCA3”) (collectively, “Category 1 Programs”), which we will have the right to co-commercialize in the United States. In addition, the Takeda will haveCollaboration provided Takeda with the right to exclusively license multiple preclinical programs for CNS disorders, including Alzheimer’s disease and Parkinson’s disease (collectively, “Category 2 Programs”). In April 2018, the Takeda Collaboration became effective and Takeda paid Wave $110.0 million as an upfront payment. Takeda also agreed to fund Wave’sour research and preclinical activities in the amount of $60.0 million during the four-year research term and to reimburse Wave for any collaboration-budgeted research and preclinical expenses incurred by Waveus that exceed that amount.

On October 15, 2021, we and Takeda entered into the Second Amendment (the “Amendment”) to the Takeda Collaboration Agreement, which amended the Category 2 component of the two-part collaboration (the “Category 2 Programs”). As discussed above, under Category 2 of the Takeda Collaboration Agreement, we had granted Takeda the right to exclusively license multiple preclinical programs for CNS disorders during a four-year research term. Pursuant to the terms of the Amendment, we and Takeda discontinued the Category 2 component of the Takeda Collaboration Agreement and Takeda paid us an additional $22.5 million for collaboration-related research and preclinical expenses. As a result of the Amendment, we are free to advance our CNS programs independently or enter partnerships in the CNS field outside of the three specified targets, C9orf72, HTT and ATXN3, including WVE-004 and WVE-003, that are part of the ongoing late-stage Category 1 Programs.  The Category 1 component of the original Takeda Collaboration Agreement remains in effect and is unchanged by the Amendment.

Simultaneously with Wave USA and Wave UK’s entry into the collaboration and license agreement with Takeda (the “Takeda Collaboration Agreement”), the CompanyAgreement, we entered into a share purchase agreement with Takeda (the “Takeda Equity Agreement,” and together with the Takeda Collaboration Agreement, the “Takeda Agreements”) pursuant to which it agreed to sell to Takeda 1,096,892 of itsour ordinary shares at a purchase price of $54.70 per share. In April 2018, the Companywe closed the Takeda Equity Agreement and

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received aggregate cash proceeds of $60.0 million. The parties also agreed for the shares purchased by Takeda areto be subject to certain lock-up and standstill restrictions and carry certain registration rights, customary for transactions of this kind.

With respect to Category 1 Programs, Wavewe will be responsible for researching and developing products and companion diagnostics for Category 1 Programs through completion of the first proof of mechanism study for such products. Takeda will have an exclusive option for each target and all associated products and companion diagnostics for such target, which it may exercise at any time through completion of the proof of mechanism study. If Takeda exercises this option, Wavewe will receive an opt-in payment and will lead manufacturing and joint clinical co-development activities and Takeda will lead joint co-commercial activities in the United States and all commercial activities outside of the United States. Global costs and potential profits will be shared 50:50 and Wavewe will be eligible to receive development and commercial milestone payments. In addition to its 50% profit share, Wave iswe are eligible to receive option exercise fees and development and commercial milestone payments for each of the Category 1 Programs.

With respect to Category 2 Programs, Wave has granted Takeda the right to exclusively license multiple preclinical programs during a four-year research term (subject to limited extension for programs that were initiated prior to the expiration of the research term, in accordance with the Takeda Collaboration Agreement). During that term, the parties may collaborate on preclinical programs for up to six targets at any one time. Wave will be responsible for researching and preclinically developing products and companion diagnostics directed to the agreed upon targets through completion of IND-enabling studies in the first major market country. Thereafter, Takeda will have an exclusive worldwide license to develop and commercialize products and companion diagnostics directed to such targets, subject to Wave’s retained rights to lead manufacturing activities for products directed to such targets. Takeda will fund Wave’s research and preclinical activities in the amount of $60.0 million during the research term and will reimburse Wave for any collaboration-budgeted research and preclinical expenses incurred by Wave that exceed that amount. Wave is also eligible to receive tiered high single-digit to mid-teen royalties on Takeda’s global commercial sales of products from each Category 2 Program.

Under the Takeda Collaboration Agreement, each party grants to the other party specific intellectual property licenses to enable the other party to perform its obligations and exercise its rights under the Takeda Collaboration Agreement, including license grants to enable each party to conduct research, development and commercialization activities pursuant to the terms of the Takeda Collaboration Agreement.

The term of the Takeda Collaboration Agreement commenced on April 2, 2018 and, unless terminated earlier, will continue until the date on which: (i) with respect to each Category 1 Program target for which Takeda does not exercise its option, the expiration or termination of the development program with respect to such target; or (ii) with respect to each Category 1 Program target for which Takeda exercises its option, the date on which neither party is researching, developing or manufacturing any products or companion diagnostics directed to such target; or (iii) with respect to each Category 2 Program target, the date on which royalties are no longer payable with respect to products directed to such target.

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Takeda may terminate the Takeda Collaboration Agreement for convenience on 180 days’ notice, in its entirety or on a target-by-target basis. Subject to certain exceptions, each party has the right to terminate the Takeda Collaboration Agreement on a target-by-target basis if the other party, or a third party related to such party, challenges the patentability, enforceability or validity of any patents within the licensed technology that cover any product or companion diagnostic that is subject to the Takeda Collaboration Agreement. In the event of any material breach of the Takeda Collaboration Agreement by a party, subject to cure rights, the other party may terminate the Takeda Collaboration Agreement in its entirety if the breach relates to all targets or on a target-by-target basis if the breach relates to a specific target. In the event that Takeda and its affiliates cease development, manufacturing and commercialization activities with respect to compounds or products subject to the Takeda Collaboration Agreement and directed to a particular target, Wavewe may terminate the Takeda Collaboration Agreement with respect to such target. Either party may terminate the Takeda Collaboration Agreement for the other party’s insolvency. In certain termination circumstances, Wavewe would receive a license from Takeda to continue researching, developing and manufacturing certain products, and companion diagnostics.

Asuragen

In November 2019, we entered into an agreement with Asuragen, Inc. (which was acquired by Bio-Techne Corporation on April 6, 2021) (“Asuragen”), a molecular diagnostics company, for the development and potential commercialization of companion diagnostics for our investigational allele-selective therapeutic programs targeting HD. This collaboration aims to useuses Asuragen’s market-leading repetitive sequence diagnostic expertise to provide scalable SNP phasing to support potential global development programs and future commercialization at a global level. Asuragen is leveraginghas leveraged its AmplideX® PCR technology to develop companion diagnostic tests designed to size and phase HTT CAG repeats with the three SNPs targeted by our WVE-120101, WVE-120102, and WVE-003previous investigational therapeutic programs.programs in HD, as well as WVE-003, our current HD program being investigated in the ongoing SELECT-HD clinical trial. These tests are designed to aid clinicians in selecting HD patients who could be appropriate for one or more of our HD compounds by identifying the SNPs that are in phase with the CAG-expanded allele.

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Our Research Collaborations

We have partnered with leading academic researchers and organizations to complement our capabilities to develop potential medicines, expand our knowledge of disease biology, and better understand the potential of our oligonucleotides.

University of Oxford; Professor Matthew Wood’s Laboratory

Since April 2015, we have been collaborating withOxford -- Dr. Matthew J.A. Wood Professor of Neuroscience at the University of Oxford and Co-Director of the Oxford Centre for Neuromuscular Science under a translational research collaboration agreement with The Chancellor, Masters, and Scholars of the University of Oxford (“Oxford”). Dr. Wood’s research is-- investigating therapeutic approaches using our novel stereopure antisense oligonucleotides to target mRNA in the field of degenerative disorders of the nervous system and muscle. His laboratory’s main focus is the investigation of novel therapeutic approaches using short nucleic acids to target mRNA. His team has been investigating the potential of single-stranded antisense oligonucleotides for the modification of mRNA splicing. In October 2016, we extended our research collaboration in order for Oxford to characterizemuscle; characterizing our proprietary isomersoligonucleotides in murine models to further improve the pharmacology of oligonucleotides using our novel chemistries.

University of Massachusetts Medical School

For our C9orf72 program, we have been working in collaboration with -- Dr. Robert H. Brown, Jr., the Leo P. and Theresa M. LaChance Chair in Medical Research and Chair of the Department of Neurology at UMMS, an internationally known researcher and physician in the field. Our work with UMMS is focused on -- characterizing our proprietary isomers in orderstereopure antisense oligonucleotides to improve the pharmacology of oligonucleotides for the treatment of ALS and FTD andwhile investigating the mechanisms of action of specific and efficient knockdown of the targeted mutant C9orf72 mRNA.

Western Washington University -- Jeff Carroll, PhD -- understanding the role of preserving wild-type huntingtin protein in the context of knocking down mutant huntingtin protein in murine models.

Grenoble Institute of Neurosciences -- Frédéric Saudou, PhD -- understanding the role of wild-type huntingtin protein in cellular models of HD, with Anselme Perrier, PhD of the Commissariat a l’Energie Atomique.

IRBM S.p.A. -- developing an assay to measure wild-type huntingtin protein in human cerebrospinal fluid.

University of Louisville -- Maureen McCall, PhD -- investigating therapeutic approaches using our proprietary stereopure antisense oligonucleotides in a miniature swine model of autosomal dominant retinitis pigmentosa caused by the Rho P23H mutation.

University College London -- Adrian Isaacs, PhD -- developing a biomarker assay to detect the polyGP protein present in the cerebrospinal fluid of ALS and FTD patients with the C9orf72 mutation.

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Manufacturing

To provide internal cGMP manufacturing capabilities and increase control and visibility of our drug product supply chain, we entered into a lease in September 2016 for a multi-use facility of approximately 90,000 square feet in Lexington, Massachusetts and initiated the build out of manufacturing space and related capabilities. Through our internal manufacturing, we have the capacity to support multiple discovery-, preclinical-, and early clinical-stage programs and have the established expertise to efficiently conduct manufacturing runs for oligonucleotides across a spectrum of modalities. In addition to manufacturing space, the Lexington facility includes additional laboratory and office space. This facility supplements our existing Cambridge, Massachusetts laboratory and office space headquarters, enhances our ability to secure drug substance for current and future development activities and may provide commercial-scale manufacturing capabilities. In July 2017, we took occupancy of the Lexington facility and began manufacturing production in the fourth quarter of 2017.

We believe that we have sufficient manufacturing capacity through our third-party contract manufacturers andleveraging our internal manufacturing facilitycapabilities along with expertise from CMOs facilitates our growth and enhances our ability to meet oursecure drug substance for current and future research, clinical and early-stage commercial needs.development activities. We believe that the addition of our internal cGMP manufacturing capabilities, together with the supply capacity we have established externally, will be sufficient to meet our anticipated manufacturing needs for the next several years. We monitor the availability of capacity for the manufacture of drug substance and drug product and believe that our supply agreements with our contract manufacturers and the lead times for new supply agreements would allow us to access additional capacity if needed. We believe that our product candidates can be manufactured at scale and with production and procurement efficiencies that will result in commercially competitive costs.

Intellectual Property

We believe that we have a strong intellectual property position relating to the development and commercialization of our stereopure oligonucleotides. Our intellectual property portfolio includes filings designed to protect stereopure oligonucleotide compositions generally, as well as filings designed to protect stereopure compositions of oligonucleotides with particular stereochemical patterns (for example, that affect or confer biological activity). Our portfolio also includes filings for both proprietary methods and reagents, as well as various chemical methodologies that enable production of such stereopure oligonucleotide compositions. In addition, our portfolio includes filings designed to protect methods of using stereopure oligonucleotide compositions and filings designed to protect particular stereopure oligonucleotide products, such as those having a particular sequence, pattern of nucleoside and/or backbone modification, pattern of backbone linkages and/or pattern of backbone chiral centers.

We own or have rights to worldwide patent filings that protect our proprietary technologies for making stereopure oligonucleotide compositions, and that also protect the compositions themselves, as well as methods of using them, including in the treatment of diseases. Our portfolio includes multiple issued patents, including in major market jurisdictions such as the United States, Europe and Japan.  We also have applications pending in multiple jurisdictions around the world, including these major market jurisdictions.

Synthetic Methodologies

Our patent portfolio includes multiple families that protect synthetic methodologies and/or reagents for generating stereopure oligonucleotide compositions. Certain synthetic methodologies and/or reagents are covered by families which include two issued Japanese patents that have terms that extend to 2022-2025.  

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Additional synthetic methodologies and/or reagents are protected by other families in our patent portfolio. Certain such families have 20-year expiration dates that range from 2029 to at least 2040.2041. Some of these families have issued patents in several jurisdictions, including in major market jurisdictions such as the United States, Europe, and/or Japan, have pending applications in multiple jurisdictions including in these major market jurisdictions, or are in the international stage.

We also co-own with the University of Tokyo certain filings that are directed to certain methods and/or reagents for synthesizing oligonucleotides; their 20-year expiration dates fall in 2031.

Stereopure Oligonucleotide Compositions

Certain of our patent filings protect stereopure compositions, particularly of therapeutically relevant oligonucleotides. Some such filings are directed to compositions whose oligonucleotides are characterized by particular patterns of chemical modification (including modifications of bases, sugars and/or internucleotidic linkages) and/or of internucleotidic linkage stereochemistry. Certain patent filings describe specific compositions designed for use in the treatment of particular diseases. Several of our patent filings directed to stereopure compositions have entered national stage prosecution in multiple jurisdictions and some have issued in one or more jurisdictions; others are in the international stage. Certain filings offer 20-year protection terms that range from 2033 to at least 2040.2041.

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We also co-own with Shin Nippon Biomedical Laboratories, Ltd. various patent families, some of which include one or more issued patents, including in major market jurisdictions; these filings have 20-year terms extending to 2033-2035.

Future Filings

We maintain a thoughtful and ambitious program for developing and protecting additional intellectual property, including new synthetic methodologies and reagents. We also intend to prepare and submit patent filings specifically directed to protecting individual product candidates and their uses as we finalize leads and collect relevant data, which is expected to include comparison data confirming novel and/or beneficial attributes of our product candidates.

Singapore Intellectual Property Law

Section 34 of the Singapore Patents Act 1994 of Singapore (the “Singapore Patents Act”) provides that a person residing in Singapore is required to obtain written authorization from the Singapore Registrar of Patents (the “Registrar”) before filing an application for a patent for an invention outside of Singapore, unless all of the following conditions have been satisfied: (a) the person has filed an application for a patent for the same invention in the Singapore Registry of Patents at least two months before the filing of the patent application outside Singapore, and (b) the Singapore Registrar of Patents has not, in respect of this patent application, given directions to prohibit or restrict the publication of information contained in the patent application or its communication to any persons or description of persons pursuant to Section 33 of the Singapore Patents Act, or if the Registrar has given any such directions, all such directions have been revoked. A violation of Section 34 is a criminal offense punishable by a fine not exceeding S$5,000, or imprisonment for a term not exceeding two years, or both. There have been some instances where we have undertaken filings outside of Singapore, and there may be instances where we are required to make such filings in the future, without first obtaining written authorization from the Registrar. We have notified the Registrar of such filings and we have since implemented measures to address the requirements of Section 34 moving forward. To date, the Registrar has offered a compound of some of the offences considered against payment of a sum of S$50 to S$100150 per considered case. Under Singapore law, the Registrar has discretion to offer a compound of such offences against payment of a sum of money of up to S$2,000, or to prosecute the offence subject to the other penalties noted above. There remainPer requests in the Registrar’s most recent decision, we have submitted approximately 40140 patent applications in multiple patent families, most of which we have notifiedare related to previously reported applications, to the Intellectual Property Office of Singapore (“IPOS”). The IPOS may consider the filing of wheresome or all of these applications to have breached Section 34 requirements have not been complied with,per IPOS’ current interpretation of Section 34, and we are pendingwaiting for IPOS’ decision thereon.on these applications. We cannot assure you that the Registrar will offer to compound any such violations of Section 34, or that any offer to compound will be for an amount similar to previous compound offers.

Competition

The biotechnology and pharmaceutical marketplace is characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. While we believe that our expertise in oligonucleotides, scientific knowledge and intellectual property estate provide us with competitive advantages, we face potential competition from many different sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions, governmental agencies and public and private research institutions. Not only must we compete with other companies that are focused on oligonucleotides, but any product candidates that we successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future.

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Many of our competitors may have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than we do. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Mergers and acquisitions in the pharmaceutical, biotechnology and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

Huntington’s Disease

T There are no approved treatments available to slow the progression of HD. We believe, based on publicly available information, that Annexon Biosciences (Phase 2), Ionis Pharmaceuticals and Roche (Phase 3)2 planned), Mitochon Pharmaceuticals (Phase 1)2), Novartis (Phase 1 completed)2), Prilenia Therapeutics (Phase 3), PTC Therapeutics (Phase 1), and uniQure (Phase 1), and Vaccinex (Phase 2 completed)1/2) all have investigational drugs in clinical development.

Several companies have ongoing discovery or preclinical programs for HD, including Alnylam Pharmaceuticals, AskBio, Atalanta Therapeutics and Biogen, Avergen Pharmaceuticals, LocanaBio, Mitoconix Bio, NeuBase Therapeutics, Neurimmune, Novartis, Nuredis,Ophidion, PTC Therapeutics, Sangamo Therapeutics and Takeda, Spark Therapeutics, Triplet Therapeutics, Vertex Pharmaceuticals,Vico, and Voyager Therapeutics.Therapeutics, among others.

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A number of companies are developing molecules to treat symptoms associated with HD, including Azevan Pharmaceuticals (Phase 2), Alterity TherapeuticsNeurocrine Biosciences (Phase 2)3), Sage Therapeutics (Phase 1), and Stealth BioTherapeuticsSOM Biotech (Phase 2), among others.

Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

There are two treatments approved in the United States for the treatment of ALS: riluzole, approved in 1995, and edaravone, approved in 2017. There are a number of companies with potential therapeutics for the treatment of ALS in clinical development, including AB Science (Phase 3), Alector (Phase 2), Amylyx Pharmaceuticals (Pre-registration), Biogen (Phase 1 completed), Biohaven Pharmaceuticals (Phase 2/3), AB Sciences (Phase 3 completed), Orphazyme (Phase 3), BrainStorm Cell Therapeutics (Phase 3 completed), (Phase 1 completed), Biogen (Phase 1), Biohaven PharmaceuticalsPrilenia (Phase 2/3), and ALS TDIUCB (Phase 2/3), among others. We believe that two companies, Biogen (Phase 1 completed). We believe that only one company, Biogen and Alector (Phase 1)2), has initiated aare conducting clinical trialtrials targeting ALS due to a C9orf72 mutation in the United States.

Several companies have ongoing discovery or preclinical programs for ALS that may directly or indirectly target patients with the C9orf72 mutation, including AcuraStem, AGTC, Apic Bio, Biogen and Neurimmune, Locana Bio, MeiraGTx, Passage Bio, Pfizer and Sangamo Therapeutics, and uniQure.

There are no approved treatments available to slow the progression of FTD. FewMultiple companies have investigational therapies in clinical development specifically for FTD. Ionis Pharmaceuticals /Biogen (Phase 1) and AlzProTect (Phase 1) appear to beFTD, including FTD in their broader AD or tauopathies clinical development plans. Alector (Phase 3), Anavex (Phase 1 completed), Eli Lilly (Phase 1/2), Passage Bio (Phase 1/2), and TauRx Pharmaceuticals (Phase 3 complete). Alector is includingstudying its investigational therapy for FTD patients with a C9orf72 mutation in a larger clinical program.Phase 2 study.

There are several companies though with ongoing discovery or preclinical programs for FTD that may directly or indirectly target patients with the C9orf72 mutation including AGTC, Denali TherapeuticsBiogen and Takeda, Locano Bio, PassageNeurimmune, Locana Bio, Pfizer and Sangamo Therapeutics, and uniQure.

Duchenne Muscular Dystrophy

There are two treatments approved in the United States for the treatment of DMD in patients who have a confirmed mutation of the DMD gene amenable to exon 53 skipping: Sarepta Therapeutics’ Vyondys 53 (golodirsen), an exon skipping nucleic acid therapeutic, was approved by the FDA forin 2019, and NS Pharma’s Viltepso (viltolarsen), an exon skipping nucleic acid therapeutic, was approved by the treatment of DMDFDA in 2020. Both therapies received accelerated approval, as the United States in 2019. The FDA concluded that the data submitted by each company demonstrated an increase in dystrophin production that is reasonably likely to predict clinical benefit in some patients with DMD who have a confirmed mutation of the DMD gene amenable to exon 53 skipping. No clinical benefit of golodirsen or viltolarsen has been established. Thus, in accordance with the U.S. accelerated approval regulations, the FDA is requiring Sarepta and NS Pharma to each conduct a clinical trial to verify and describe thetheir drug’s clinical benefit. The requiredSarepta’s study of golodirsen would need to assess whether golodirsen improves motor function of DMD patients with a confirmed mutation of the DMD gene amenable to exon 53 skipping. If the trial fails to verify clinical benefit, the FDA could initiate proceedings to withdraw approval of the drug.

skipping, and NS Pharma’s Viltepso (viltolarsen), an exon skipping nucleic acid therapeutic, was approved by the FDA for the treatmentstudy of DMD in the United States in 2020. The FDA concluded that the data submitted demonstrated an increase in dystrophin production that is reasonably likely to predict clinical benefit in some patients with DMD who have a confirmed mutation of the DMD gene amenable to exon 53 skipping. NS Pharma has been required by the FDA to conduct a clinical trial to confirm the drug’s clinical benefit. The studyviltolarsen is designed to assess whether viltolarsen improves the time to stand for DMD patients amenable to exon 53 skipping. If the trial failstrials fail to verify clinical benefit, the FDA maycould initiate proceedings to withdraw approval of the respective drug.

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Several other companies have investigational drugs in clinical development directly targeting DMD more broadly, including patients amenable to exon 53 skipping or DMD more broadly.skipping. These include Astellas Pharma (Phase 1), Dystrogen Therapeutics (Phase 1), FibroGen (Phase 3), Pfizer (Phase 3), PTC Therapeutics (Phase 2)3), Santhera PharmacauticalsPharmaceuticals (Phase 3)2), Sarepta Therapeutics (Phase 2)3), and Solid Biosciences (Phase 1/2)., among others.  Based on available information, we do not believe there are other companies with ongoing clinical programs directly targeting DMD patients amenable to exon 53 skipping.

Several companies also have ongoing preclinical programs for DMD that may directly or indirectly target patients amenable to exon 53 skipping. These companies include Audentes Therapeutics, Catabasis Pharmaceuticals,Astellas, Code Bio, CRISPR Therapeutics, Dystrogen Therapeutics, FibroGen,Daiichi Sankyo, Fulcrum Therapeutics, Immunoforge, PepGen, Precision BioSciences, REGENXBIO, Sarepta Therapeutics, and Strykagen.Ultragenyx, among others.

Alpha-1 Antitrypsin Deficiency (“AATD”)

There are five treatments approved in the USUnited States for AATD: Prolastin, Prolastin-C, Aralast NP, Zemaira, and Glassia. All five contain plasma-derived human alpha1-proteinase inhibitor and are indicated for chronic augmentation and maintenance therapy in adults with emphysema due to congenital deficiency of alpha1-proteinase inhibitor (Alpha1-PI). The FDA also notes in the prescribing information for each notes that the effect of augmentation therapy with any alpha1-proteinase inhibitor on pulmonary exacerbations and on the progression of emphysema in Alpha1-PI deficiency has not been demonstrated in randomized, controlled clinical trials.

There are also a number of companies with investigational drugs in clinical development: Arrowhead Pharmaceuticals and Takeda (Phase 3)2), VertexCentessa (Phase 2)1), Dicerna Pharmaceuticals and Alnylam Pharmaceuticals (Phase 2), InhibRx (Phase 1), Kamada (Phase 3), Mereo BioPharma (Phase 2), InhibRx (Phase 2), AGTC (Phase 2) and Santhera Pharmacauticals (Phase 1 completed)1).

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There are also several companies with ongoing discovery or preclinical programs for AATD including Apic Bio, Beam Therapeutics, Editas Medicine,Biomarin, Intellia Therapeutics, KorroBio, Krystal Biotech, LogicBio Therapeutics, Sangamo Therapeutics, Shape Therapeutics, and Vertex ,Pharmaceuticals, among others.

ADAR-mediated RNA Editing (“ADAR-editing”ADAR editing”)

TheThere are several companies pursuing editing approaches that may compete with our ADAR-editingADAR editing modality. These include companies are in various stages of development (discovery through the clinic) and are developing investigational drugs via viral and non-viral delivery for RNA editing (Shape Therapeutics and Korro Bio), DNA base-editing (Beam), and DNA editing (Editas Medicine, Intellia Therapeutics, and Sangamo Therapeutics), among others. These companies may leverage these approaches to target the same indications that we intend to target or indications where we do not currently plan to compete.

Government Regulation

FDA Approval Process for Drug Products

In the United States, pharmaceutical products are subject to extensive regulation by the FDA. The Federal Food, Drug and Cosmetic Act (“FDCA”), and other federal and state statutes and regulations, govern, among other things, the research, development, testing, manufacture, storage, recordkeeping, approval, labeling, promotion and marketing, distribution, post-approval monitoring and reporting, sampling, and import and export of pharmaceutical products. Failure to comply with applicable FDA or other requirements may subject a pharmaceutical company to a variety of administrative or judicial sanctions, such as the FDA’s refusal to approve pending applications, a clinical hold, warning letters, recall or seizure of drug products, partial or total suspension of production, withdrawal of drug products from the market, injunctions, fines, civil penalties or criminal prosecution.

FDA approval is required before any new drug, such as a new molecular or chemical entity, or a new dosage form, new use or new route of administration of a previously approved product, can be marketed in the United States. The process required by the FDA before a new drug product may be marketed in the United States generally involves:

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The manufacturing development, preclinical and clinical testing, and review process requires substantial time, effort and financial resources. Manufacturing development includes laboratory evaluation of product chemistry, formulation, development of manufacturing and control procedures, evaluation of stability, and the establishment of procedures to ensure continued product quality.

Nonclinical tests include in vitro and in vivo animal studies to assess the toxicity and other safety characteristics of the product candidate, as well as other important aspects of drug pharmacology. The results of nonclinical tests, together with manufacturing information, analytical data and a proposed clinical trial protocol and other information, are submitted as part of an IND to the FDA.

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Some long-term nonclinical testing to further establish the safety profile of the product candidate, as well as manufacturing processes development and drug quality evaluation, continues after the IND is submitted. An IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, raises concerns or questions related to the proposed clinical trial and places the IND on a clinical hold. In such a case, the IND sponsor must resolve all outstanding concerns before the clinical trial can begin. As a result, our submission of an IND may not result in FDA authorization to commence a clinical trial. A separate submission to an existing IND must also be made for each successive clinical trial conducted during product development, or if changes are made in trial design. Even if the IND becomes effective and the trial proceeds without initial FDA objection, the FDA may stop the trial at a later time if it has concerns, such as if unacceptable safety risks arise.

Further, an independent IRB atfor each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and informed consent information for subjects before the trial commences at that site and it must perform an ongoing review of the research on an annual basis until the trial is completed. The FDA or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects or patients are being exposed to an unacceptable health risk or that the trials are not being conducted in accordance with the clinical plan or in compliance with GCP. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the drug has been associated with unexpected serious harm to patients.

Clinical trials involve the administration of the product candidate to human subjects under the supervision of qualified investigators in accordance with GCP requirements, which include the requirement that all research subjects provide their informed consent in writing for their participation in any clinical trial. Sponsors of clinical trials of certain FDA-regulated products generally must register and report, atdisclose certain clinical trial information to a public registry maintained by the National Institutes of Health (“NIH”)-maintained website clinicaltrials.gov, key parameters. In particular, information related to the product, patient population, phase of ainvestigation, study sites and investigators and other aspects of the clinical trial is made public as part of the registration of the clinical trial. For purposesCompetitors may use this publicly available information to gain knowledge regarding the progress of an NDA submission, humandevelopment programs. Although sponsors are also obligated to disclose the results of their clinical trials after completion, disclosure of the results can be delayed in some cases for up to two years after the date of completion of the trial. Failure to timely register a covered clinical study or to submit study results as provided for in the law can give rise to civil monetary penalties and also prevent the non-compliant party from receiving future grant funds from the federal government. The NIH’s Final Rule on ClinicalTrials.gov registration and reporting requirements became effective in 2017, and the government has recently begun enforcing those requirements against non-compliant clinical trial sponsors.

Human clinical trials are typically conducted in the following sequential phases, which may overlap or be combined:

Progress reports detailing progress and safety data gathered from clinical trials must be submitted at least annually to the FDA. Safety reports are submitted more frequently if certain serious adverse effects or SAEs,(“SAEs”) occur. Phase 1, Phase 2 and Phase 3 clinical trials

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may not be completed successfully within any specified period, or at all. The FDA will typically inspect one or more clinical sites to assure compliance with GCP and the integrity of the clinical data submitted as part of NDA review. Information related to the product, patient population, phase of investigation, study sites and investigators and other aspects of the clinical trial is made public as part of the registration of the clinical trial. Sponsors are also obligated to disclose the results of most clinical trials after completion, although in some cases disclosure of the results of these trials can be delayed for up to two years after the trial completion date. Competitors may use this publicly available information to gain knowledge regarding the progress of development programs.

Assuming successful completion of the required clinical testing, the results of the preclinical studies and clinical trials, along with information relating to the product’s pharmacology, chemistry, manufacturing, and controls, and proposed labeling, are submitted to the FDA as part of an NDA requesting approval to market the product for one or more indications. Data may come from company-sponsored clinical trials intended to test the safety and efficacy of a product’s use or from a number of alternative sources, including

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studies initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety and efficacy of the investigational product to the satisfaction of the FDA. Under federal law, the fee for the submission of an NDA with clinical data is substantial (for example, for FY2021fiscal year 2022 this application fee exceeds $2.8$3.1 million), and the sponsor of an approved NDA is also subject to an annual program fee, currently more than $330,000$360,000 per program. These fees are typically adjusted annually, but exemptions and waivers may be available under certain circumstances, including NDA fees for products with orphan designation.

The FDA has 60 days from its receipt of an NDA to determine whether the application will be accepted for filing based on the agency’s threshold determination that it is sufficiently complete to permit substantive review. The FDA may request additional information rather than accept an NDA for filing. Any resubmitted application, following a refusal to file action, is also subject to 60-day review before the FDA accepts it for filing.

Under the PDUFA,Prescription Drug User Fee Act (“PDUFA”), for original NDAs, the FDA has ten months from the filing date in which to complete its initial review of a standard application and respond to the applicant, and six months from the filing date for an application with priority review.  For all new molecular entity or NME,(“NME”) NDAs, the ten and six-month time periods run from the filing date; for all other original applications, the ten and six-month time periods run from the submission date. Despite these review goals, it is not uncommon for FDA review of an NDA to extend beyond the goal date.

Once the submission has been accepted for filing, the FDA begins an in-depth review. As noted above, the FDA has agreed to specified performance goals in the review process of NDAs. Most such applications are meant to be reviewed within ten months from the date it is accepted for filing (i.e., 12 months), and most applications for “priority review” products are meant to be reviewed within six months from the date the application is accepted for filing (i.e., 8 months). The review process may be extended by the FDA for three additional months to consider new information or in the case of a clarification provided by the applicant to address an outstanding deficiency identified by the FDA following the original submission.

Before approving an NDA, the FDA may inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP. The FDA may also inspect one or more of the clinical sites where pivotal trials were conducted and the contract research organization facilities with oversight of the trial, in order to ensure compliance with GCP and the integrity of the study data.

Additionally, the FDA may refer any NDA, including applications for novel biologic candidates which present difficult questions of safety or efficacy, to an advisory committee. Typically, an advisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendation of an advisory committee, but it considers such recommendations when making final decisions on approval. The FDA likely will re-analyze the clinical trial data, which could result in extensive discussions between the FDA and the applicant during the review process. The FDA also may require submission of a risk evaluation and mitigation strategy or REMS,(“REMS”) if it determines that a REMS is necessary to ensure that the benefits of the drug outweigh its risks and to assure the safe use of the drug or biological product. The REMS could include medication guides, physician communication plans, assessment plans and/or elements to assure safe use, such as restricted distribution methods, patient registries or other risk minimization tools. The FDA determines the requirement for a REMS, as well as the specific REMS provisions, on a case-by-case basis. If the FDA concludes a REMS is needed, the sponsor of the NDA must submit a proposed REMS. The FDA will not approve an NDA without a REMS, if required.

In determining whether a REMS is necessary, the FDA may consider the size of the population likely to use the drug, the seriousness of the disease or condition to be treated, the expected benefit of the drug, the duration of treatment, the seriousness of known or potential adverse events, and whether the drug is an NME. If the FDA determines a REMS is necessary, the drug sponsor must agree to the REMS plan at the time of approval, or at a later date should significant new risk information come to light. A REMS may be required to include various elements, such as a medication guide, a communication plan to educate healthcare providers of the drug’s risks, limitations on who may prescribe or dispense the drug, or other elements to assure safe use that the FDA deems necessary to assure the benefits of use of the drug outweigh its risks. In addition, the REMS must include a timetable to assess the strategy, often at 18 months, 3 years, and 7 years after the strategy’s approval. The FDA may also impose a REMS requirement on a drug already on the market if the FDA determines, based on new safety information, that a REMS is necessary to ensure that the drug’s benefits outweigh its risks.

Under the Pediatric Research Equity Act or PREA,(“PREA”), as amended, an NDA or supplement to an NDA must contain data that are adequate to assess the safety and efficacy of the product candidate for the claimed indications in all relevant pediatric populations and to support dosing and administration for each pediatric population for which the product is safe and effective. The FDA may grant deferrals for submission of pediatric data or full or partial waivers. The Food and Drug Administration Safety and Innovation Act, or the FDASIA, enacted in 2012, made permanent PREA to requirerequires a sponsor who is planning to submit a marketing application for a product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration to submit an initial Pediatric Study Plan or PSP,(“PSP”) within sixty days of an end-of-Phase 2 meeting or, if there is no such meeting, as early

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as practicable before the initiation of the Phase 3 or Phase 2/3 clinical trial. The initial PSP must include an outline

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of the pediatric study or studies that the sponsor plans to conduct, including trial objectives and design, age groups, relevant endpoints and statistical approach, or a justification for not including such detailed information, and any request for a deferral of pediatric assessments or a full or partial waiver of the requirement to provide data from pediatric studies along with supporting information. The FDA and the sponsor must reach an agreement on the PSP. A sponsor can submit amendments to an agreed upon initial PSP at any time if changes to the pediatric plan need to be considered based on data collected from pre-clinical studies, early phase clinical trials or other clinical development programs.

The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is cGMP-compliant to assure and preserve the product’s identity, strength, quality and purity. The approval process is lengthy and often difficult, and the FDA may refuse to approve an NDA if the applicable regulatory criteria are not satisfied or may require additional clinical or other data and information. On the basis of the FDA’s evaluation of the NDA and accompanying information, including the results of the inspection of the manufacturing facilities, it may issue an approval letter or a Complete Response Letter (CRL)(“CRL”). An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A CRL indicates that the review cycle for an application is complete and that the application will not be approved in its present form. CRLs outline the deficiencies in the submission and may require substantial additional testing or information in order for the FDA to reconsider the application. The CRL may require additional clinical or other data, additional pivotal Phase 3 clinical trial(s) and/or other significant and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. If a CRL is issued, the applicant may choose to either resubmit the NDA or NDA addressing all of the deficiencies identified in the letter, or withdraw the application. The FDA has committed to reviewing such resubmissions in response to an issued CRL in either two or six months depending on the type of information included. Even with submission of this additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval. If and when the deficiencies have been addressed to the FDA’s satisfaction, the FDA will typically issue an approval letter.

The FDA may withdraw product approval if ongoing regulatory requirements are not met or if safety problems are identified after the product reaches the market. In addition, the FDA may require post-approval testing, including Phase 4 studies, and surveillance programs to monitor the effect of approved products which have been commercialized, and the FDA has the authority to prevent or limit further marketing of a product based on the results of these post-marketing programs. Products may be marketed only for the approved indications and in accordance with the provisions of the approved label and, even if the FDA approves a product, the FDA may limit the approved indications for use for the product or impose other conditions, including labeling or distribution restrictions or other risk-management mechanisms, such as a Boxed Warning, which highlights a serious safety concern that should be mitigated under a REMS program. Further, if there are any modifications to the product, including changes in indications, labeling, or manufacturing processes or facilities, a company is generally required to submit and obtain FDA approval of a supplemental NDA, which may require the company to develop additional data or conduct additional nonclinical studies and clinical trials.

Fast Track, Breakthrough Therapy and Priority Review Designations

The FDA is authorized to designate certain products for expedited development or review if they are intended to address an unmet medical need in the treatment of a serious or life-threatening disease or condition. These programs include fast track designation, breakthrough therapy designation and priority review designation.

To be eligible for a fast track designation, the FDA must determine, based on the request of a sponsor, that a product is intended to treat a serious or life-threatening disease or condition and demonstrates the potential to address an unmet medical need by providing a therapy where none exists or a therapy that may be potentially superior to existing therapy based on efficacy or safety factors. Fast track designation provides opportunities for more frequent interactions with the FDA review team to expedite development and review of the product. The FDA may also review sections of the NDA for a fast track product on a rolling basis before the complete application is submitted, if the sponsor and the FDA agree on a schedule for the submission of the application sections and the sponsor pays any required user fees upon submission of the first section of the NDA. In addition, fast track designation may be withdrawn by the sponsor or rescinded by the FDA if the designation is no longer supported by data emerging from the clinical trial process.

In addition, with the enactment of FDASIA in 2012 Congress created a new regulatory program for product candidates designated by FDA as “breakthrough therapies” upon a request made by the IND sponsors. A breakthrough therapy is defined as a drug or biologic that is intended, alone or in combination with one or more other drugs or biologics, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug or biologic may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Drugs or biologics designated as breakthrough therapies are also eligible for accelerated approval of their respective marketing applications. The FDA must take certain actions with respect to breakthrough therapies, such as holding timely meetings with and providing advice to the product sponsor, which are intended to expedite the development and review of an application for approval of a breakthrough therapy.

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Finally, the FDA may designate a product for priority review if it is a drug or biologic that treats a serious condition and, if approved, would provide a significant improvement in safety or effectiveness over existing therapy. The FDA determines at the time that the

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marketing application is submitted, on a case- by-case basis, whether the proposed drug represents a significant improvement in treatment, prevention or diagnosis of disease when compared with other available therapies. Significant improvement may be illustrated by evidence of increased effectiveness in the treatment of a condition, elimination or substantial reduction of a treatment-limiting drug reaction, documented enhancement of patient compliance that may lead to improvement in serious outcomes, or evidence of safety and effectiveness in a new subpopulation. A priority review designation is intended to direct overall attention and resources to the evaluation of such applications, and to shorten the FDA’s goal for taking action on a marketing application from ten months to six months for an NME NDA from the date of filing.

Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened. Furthermore, fast track designation, breakthrough therapy designation and priority review do not change the standards for approval and may not ultimately expedite the development or approval process.

Accelerated Approval Pathway

In addition, products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may receive accelerated approval from the FDA and may be approved on the basis of adequate and well-controlled clinical trials establishing that the drug product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit. The FDA may also grant accelerated approval for such a drug or biologic when the product has an effect on an intermediate clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality or IMM,(“IMM”) and that is reasonably likely to predict an effect on IMM or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of approval, the FDA will require that a sponsor of a drug receiving accelerated approval perform post-marketing clinical trials to verify and describe the predicted effect on IMM or other clinical endpoint, and the product may be subject to expedited withdrawal procedures. Drugs and biologics granted accelerated approval must meet the same statutory standards for safety and effectiveness as those granted traditional approval.

For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign, or other measure that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. Surrogate endpoints can often be measured more easily or more rapidly than clinical endpoints. An intermediate clinical endpoint is a measurement of a therapeutic effect that is considered reasonably likely to predict the clinical benefit of a drug, such as an effect on IMM. The FDA has limited experience with accelerated approvals based on intermediate clinical endpoints, but has indicated that such endpoints generally may support accelerated approval when the therapeutic effect measured by the endpoint is not itself a clinical benefit and basis for traditional approval, if there is a basis for concluding that the therapeutic effect is reasonably likely to predict the ultimate long-term clinical benefit of a drug.

The accelerated approval pathway is most often used in settings in which the course of a disease is long and an extended period of time is required to measure the intended clinical benefit of a drug, even if the effect on the surrogate or intermediate clinical endpoint occurs rapidly. For example, accelerated approval has been used extensively in the development and approval of drugs for treatment of a variety of cancers in which the goal of therapy is generally to improve survival or decrease morbidity and the duration of the typical disease course requires lengthy and sometimes large clinical trials to demonstrate a clinical or survival benefit.

The accelerated approval pathway is usually contingent on a sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug’s clinical benefit. As a result, a product candidate approved on this basis is subject to rigorous post-marketing compliance requirements, including the completion of Phase 4 or post-approval clinical trials to confirmestablish the effect on the clinical endpoint. Failure to conduct required post-approval studies, or to confirm the predicted clinical benefit of the product during post-marketing studies, would allow the FDA to withdraw approval of the drug. All promotional materials for product candidates being considered and approved under the accelerated approval program are subject to prior review by the FDA.

Modernizing Trial Design

FDA sometimes initiates pilot programs to facilitate communication or other aspects of development to help advance approval of new drugs. In August 2018, the FDA announced the establishment of a Complex Innovative Trial Design (“CID”) Pilot Meeting Program (“CID pilot program”) to facilitate the use of CID approaches in late-stage drug development and promote innovation by allowing the FDA to publicly discuss the trial designs considered through the pilot program, including for medical products that have not yet been approved by the FDA.Under the CID pilot program, the FDA will accept up to two applicants per quarter. For each meeting request granted as part of the pilot, the FDA will conduct an initial meeting and a follow-up meeting on the same CID and medical product

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within a span of approximately 120 days. Our Phase 2/3 clinical trial of suvodirsen for DMD, which in December 2019 we announced our decision to discontinue, was the first trial selected for the CID pilot program.

Post-Approval Requirements

Once an NDA is approved, a product will be subject to continuing regulation by the FDA, including, among other things, requirements relating to safety surveillance and adverse event reporting, periodic reporting, continued cGMP compliance and quality oversight, compliance with post-marketing commitments, recordkeeping, advertising and promotion, and reporting manufacturing and labeling changes, as applicable.

In addition, drug manufacturers and other entities involved in the manufacture and distribution of approved drugs (including third-party manufacturers) are required to register their establishments with the FDA and some state agencies and are subject to periodic unannounced inspections by the FDA and some state agencies for assessment of compliance with cGMP. Changes to the

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manufacturing process are strictly regulated and often require prior FDA approval before being implemented. FDA regulations also require investigation and correction, and sometimes notification of, any deviations from cGMP. These regulations impose reporting and documentation requirements on the sponsor and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain cGMP compliance.

Once an approval is granted, the FDA may withdraw the approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Discovery of previously unknown problems with a product, including adverse events of unlisted severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements such as noncompliance with cGMP or failure to correct previously identified inspection findings, may result in mandatory revisions to the approved labeling to add new safety information; imposition of post-market or clinical trials to assess new safety risks; or imposition of distribution or other restrictions under a REMS program. Other potential consequences include, among other things:

The FDA strictly regulates marketing, labeling, advertising and promotion of products that are placed on the market. While physicians may generally prescribe a drug for off-label uses, manufacturers may only promote the drug in accordance with the data provided in the approved product label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have promoted false and misleading information about the product may be subject to significant liability, both at the federal and state levels.

The FDA has authority to require a REMS from manufacturers to ensure that the benefits of a drug or biological product outweigh its risks. In determining whether a REMS is necessary, the FDA may consider the size of the population likely to use the drug, the seriousness of the disease or condition to be treated, the expected benefit of the drug, the duration of treatment, the seriousness of known or potential adverse events, and whether the drug is an NME. If the FDA determines a REMS is necessary, the drug sponsor must agree to the REMS plan at the time of approval, or at a later date should significant new risk information come to light. A REMS may be required to include various elements, such as a medication guide, a communication plan to educate healthcare providers of the drug’s risks, limitations on who may prescribe or dispense the drug, or other elements to assure safe use that the FDA deems necessary to assure the benefits of use of the drug outweigh its risks. In addition, the REMS must include a timetable to assess the strategy, often at 18 months, 3 years, and 7 years after the strategy’s approval. The FDA may also impose a REMS requirement on a drug already on the market if the FDA determines, based on new safety information, that a REMS is necessary to ensure that the drug’s benefits outweigh its risks.

In addition, the distribution of prescription pharmaceutical products is subject to the Prescription Drug Marketing Act or PDMA,(“PDMA”) which regulates the distribution of drugs and drug samples at the federal level, and sets minimum standards for the registration and regulation of drug distributors by the states. Both the PDMA and state laws limit the distribution of prescription drug product samples

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and impose requirements to ensure accountability in distribution. Most recently, the Drug Supply Chain Security Act or DSCSA,(“DSCSA”) was enacted with the aim of building an electronic system to identify and trace certain prescription drugs distributed in the United States. The DSCSA mandates phased-in and resource-intensive obligations for pharmaceutical manufacturers, wholesale distributors, and dispensers over a 10‑year period that is expected to culminate in November 2023. From time to time, new legislation and regulations may be implemented that could significantly change the statutory provisions governing the approval, manufacturing and marketing of products regulated by the FDA. It is impossible to predict whether further legislative or regulatory changes will be enacted, or FDA regulations, guidance or interpretations changed or what the impact of such changes, if any, may be.

Orphan Drug Designation

Under the Orphan Drug Act, the FDA may grant orphan drug designation to a drug intended to treat a rare disease or condition, which is defined as one affecting fewer than 200,000 individuals in the United States or more than 200,000 individuals where there is no reasonable expectation that the product development cost will be recovered from product sales in the United States. Orphan drug designation must be requested before submitting an NDA. After the FDA grants orphan drug designation, the identity of the drug and its potential orphan use will be disclosed publicly by the FDA; the posting will also indicate whether a drug is no longer designated as an orphan drug. More than one product candidate may receive an orphan drug designation for the same indication. Orphan drug designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.

Under PREA, submission of a pediatric assessment is not required for pediatric investigation of a product that has been granted orphan drug designation. However, under the FDA Reauthorization Act of 2017 (“FDASIA”), the scope of the PREA was extended to require pediatric studies for products intended for the treatment of an adult cancer that are directed at a molecular target that are determined to be substantially relevant to the growth or progression of a pediatric cancer. In addition, the FDA finalized guidance in 2018 indicating that it does not expect to grant any additional orphan drug designation to products for pediatric subpopulations of common diseases. Nevertheless, the FDA intends to still grant orphan drug designation to a drug or biologic that otherwise meets all other criteria for

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designation when it prevents, diagnoses or treats either (i) a rare disease that includes a rare pediatric subpopulation, (ii) a pediatric subpopulation that constitutes a valid orphan subset, or (iii) a rare disease that is in fact a different disease in the pediatric population as compared to the adult population.

If an orphan drug-designated product subsequently receives FDA approval for the disease for which it was designed, the product will be entitled to seven years of product exclusivity, which means that the FDA may not approve any other applications to market the same drug for the same indication, except in very limited circumstances (such as a showing of clinical superiority to the product with orphan exclusivity by means of greater effectiveness, greater safety or providing a major contribution to patient care or in instances of drug supply issues), for seven years. Orphan exclusivity does not block the approval of a different drug or biologic for the same rare disease or condition, nor does it block the approval of the same drug or biologic for different conditions. If a competitor obtains approval of the same drug, as defined by the FDA, or if our product candidate is determined to be the same drug as a competitor’s product for the same indication or disease, the competitor’s exclusivity could block the approval of our product candidate in the designated orphan indication for seven years, unless our product is demonstrated to be clinically superior to the competitor’s drug.

European Union Orphan Drug Designation

In the European Union (the “EU”), orphan drug designation by the European Commission (the “EC”) provides regulatory and financial incentives for companies to develop and market therapies that meet the following requirements: (1) the product is intended for the diagnosis, prevention or treatment of life-threatening or chronically debilitating conditions; (2) either (a) such condition affects no more than five in 10,000 persons in the European Union when the application is made, or (b) the product, without the benefits derived from orphan status, would not generate sufficient return in the European Union to justify investment; and (3) there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the European Union, or if such a method exists, the product will be of significant benefit to those affected by the condition, as defined in Regulation (EC) 847/2000. To be considered for orphan drug designation in the EU, companies must provide data that demonstrate the plausibility for use of the investigational therapy in the treatment of the disease and establish that the drug has the potential to provide relevant advantages or a major contribution to patient care over existing therapies.

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Among the incentives available to medicines designated as orphan drugs by the EC are ten-year market exclusivity in the EU after product approval, eligibility for conditional marketing authorization, protocol assistance from the European Medicines Agency at reduced fees during the product development phase and direct access to centralized marketing authorization in the EU. The exclusivity period may be reduced to six years if, at the end of the fifth year, the orphan drug designation criteria are no longer met, including where it is shown that the product is sufficiently profitable not to justify maintenance of market exclusivity. In addition, marketing authorization may be granted to a similar medicinal product with the same orphan indication during the ten-year period with the consent of the marketing authorization holder for the original orphan medicinal product or if the manufacturer of the original orphan medicinal product is unable to supply sufficient quantities of the product. Marketing authorization may also be granted to a similar medicinal product with the same orphan indication if the similar product is deemed safer, more effective or otherwise clinically superior to the original orphan medicinal product. Orphan drug designation must be requested before submitting an application for marketing authorization. Orphan drug designation does not, in itself, convey any advantage in, or shorten the duration of, the regulatory review and authorization process.

Pediatric Exclusivity and Pediatric Use

The Best Pharmaceuticals for Children Act (“BPCA”) provides NDA holders a six-month period of non-patent marketing exclusivity attached to any other exclusivity listed with FDA—patent or non-patent—for a drug if certain conditions are met. Conditions for pediatric exclusivity include a determination by the FDA that information relating to the use of a new drug in the pediatric population may produce health benefits in that population; a written request by the FDA for pediatric studies; and agreement by the applicant to perform the requested studies and the submission to the FDA, completion of the studies in accordance with the written request, and the acceptance by the FDA, of the reports of the requested studies within the statutory timeframe. The data do not need to show the product to be effective in the pediatric population studied; rather, if the clinical trial is deemed to fairly respond to the FDA’s request, the additional protection is granted. If reports of requested pediatric studies are submitted to and accepted by the FDA within the statutory time limits, whatever statutory or regulatory periods of exclusivity or patent protection cover the product are extended by six months. This is not a patent term extension, but it effectively extends the regulatory period during which the FDA cannot approve another application. The issuance of a written request does not require the sponsor to undertake the described studies. Applications under the BPCA are treated as priority applications.

The Hatch-Waxman Act and Marketing Exclusivity

In 1984, with passage of the Hatch-Waxman Amendments to the FDC Act,FDCA, Congress authorized the FDA to approve generic drugs that are the same as drugs previously approved by the FDA under the NDA provisions of the statute and also enacted Section 505(b)(2) of the FDC ActFDCA. To obtain approval of a generic drug, an applicant must submit an abbreviated new drug application or ANDA,(“ANDA”) to the agency. In support of such applications, a generic manufacturer may rely on the preclinical and clinical testing conducted for a drug product previously approved under an NDA, known as the reference listed drug or RLD.(“RLD”). Specifically, in order for an ANDA to be

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approved, the FDA must find that the generic version is identical to the RLD with respect to the active ingredients, the route of administration, the dosage form, and the strength of the drug. At the same time, the FDA must also determine that the generic drug is “bioequivalent” to the innovator drug.

Upon NDA approval of a new chemical entity or NCE,(“NCE”), which is a drug that contains no active moiety that has been approved by the FDA in any other NDA, that drug receives five years of marketing exclusivity. During the exclusivity period, the FDA cannot accept for review any ANDA or 505(b)(2) NDA submitted by another company for another version of such drug where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted one year before NCE exclusivity expires if a Paragraph IV certification is filed on an NCE patent and any time after approval if the application is filed based on a new indication or a new formulation.

The Hatch-Waxman Act also provides three years of data exclusivity for aan NDA, 505(b)(2) NDA or supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example, new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the conditions of use associated with the new clinical investigations and does not prohibit the FDA from approving follow-on applications for drugs containing the original active agent. If there is no listed patent in the Orange Book, there may not be a Paragraph IV certification, and, thus, no ANDA or 505(b)(2) NDA may be filed before the expiration of the exclusivity period. Five-year and three-year exclusivity also will not delay the submission or approval of a traditional NDA filed under Section 505(b)(1) of the FDC Act.FDCA. However, an applicant submitting a traditional NDA would be required to either conduct or obtain a right of reference to all of the preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Patent Term Restoration

Depending upon the timing, duration and specifics of FDA approval of the use of our therapeutic candidates, some of our U.S. patents may be eligible for limited patent term extension under the Hatch-Waxman Act. The Hatch-Waxman Act permits a patent restoration term of up to five years as compensation for any patent term lost during product development and the FDA regulatory review process.

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However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of an NDA, plus the time between the submission date of an NDA and the approval of that application. Only one patent applicable to an approved drug is eligible for the extension and the application for extension must be made prior to the expiration of the patent. The United States Patent and Trademark Office (“USPTO”), in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we intend to apply for restorations of patent term for some of our currently owned or licensed patents to add patent life beyond their current expiration date, depending on the expected length of clinical trials and other factors involved in the submission of the relevant NDA.

In Vitro Diagnostic Tests for Biomarkers

For some of our product candidates, we plan to work with collaborators to develop or obtain access to in vitro companion diagnostic tests to identify appropriate patients for these targeted therapies. If a sponsor or the FDA believes that a diagnostic test is essential for the safe and effective use of a corresponding therapeutic product, a sponsor will typically work with a collaborator to develop an in vitro diagnostic (“IVD”). IVDs are regulated by the FDA as medical devices, and since 2014 the agency has issued final and draft guidance documents that are intended to assist companies developing in vitro companion diagnostic devices and companies developing therapeutic products that depend on the use of a specific in vitro companion diagnostic for the safe and effective use of the product.

The three types of marketing pathways for medical devices are clearance of a premarket notification under Section 510(k) of the Federal Food, Drug, and Cosmetic Act, or FDCA (“510(k)”), approval of a premarket approval application or PMA,(“PMA”) and a de novo classification request, or de novo. If a company is required to perform clinical trials to support the safety and effectiveness of an IVD, and the IVD is viewed as a significant risk device, the sponsor will have to submit an investigational device exemption application or IDE,(“IDE”) to the FDA, which is similar in format and function to an IND. If the diagnostic test and the therapeutic drug are studied together to support their respective approvals, any clinical trials involving both product candidates must meet both the IDE and IND requirements.

The FDA expects that the therapeutic sponsor will address the need for an IVD companion diagnostic device in its therapeutic product development plan and that, in most cases, the therapeutic product and its corresponding IVD companion diagnostic device will be developed contemporaneously. If the companion diagnostic test will be used to make critical treatment decisions such as patient selection, treatment assignment, or treatment arm, it will likely be considered a significant risk device for which a clinical trial will be required. After approval, the use of an IVD companion diagnostic device with a therapeutic product will be stipulated in the instructions for use in the labeling of both the diagnostic device and the corresponding therapeutic product. In addition, a diagnostic

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test that was approved through the PMA process, or one that was cleared through the 510(k) process or reclassified through the de novo process, and placed on the market will be subject to many of the same regulatory requirements that apply to approved drugs.

However, the FDA may decide that it is appropriate to approve such a therapeutic product without an approved or cleared in vitro companion diagnostic device when the drug or therapeutic biologic is intended to treat a serious or life-threatening condition for which no satisfactory alternative treatment exists and the FDA determines that the benefits from the use of a product with an unapproved or uncleared in vitro companion diagnostic device are so pronounced as to outweigh the risks from the lack of an approved or cleared in vitro companion diagnostic device. The FDA encourages sponsors considering developing a therapeutic product that requires a companion diagnostic to request a meeting with both relevant device and therapeutic product review divisions to ensure that the product development plan will produce sufficient data to establish the safety and effectiveness of both the therapeutic product and the companion diagnostic. Because the FDA’s policies on companion diagnostics is set forth only in guidance, this policy is subject to change and is not legally binding.

European Union Regulation of Drug Products

In addition to regulations in the United States, we are and will be subject, either directly or through our distribution partners, to a variety of regulations in other jurisdictions governing, among other things, clinical trials, the privacy of personal data and commercial sales and distribution of our products, if approved.

Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in non-U.S. countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a process that requires the submission of a clinical trial application much like an IND prior to the commencement of human clinical trials. In Europe, for example, a clinical trial application (“CTA”), must be submitted to the competent national health authority and to independent ethics committees in each country in which a company plans to conduct clinical trials. Once the CTA is approved in accordance with a country’s requirements, clinical trials may proceed in that country. Under the EU Clinical Trials Regulation, a harmonized assessment and supervision processes was implemented as of January 31, 2022 for clinical trials throughout the EU, via a Clinical Trials Information System (“CTIS”). The CTIS will contain the centralized EU portal and database for clinical trials conducted in the EU and will allow for a centralized review process.  This harmonized submission process became mandatory for new CTA submissions to be filed beginning on February 1, 2023.

The requirements and process governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country, even though there is already some degree of legal harmonization in the European UnionEU member states resulting from the

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national implementation of underlying E.U.EU legislation. In all cases, the clinical trials are conducted in accordance with GCP and other applicable regulatory requirements.

To obtain a marketing license for a new drug or medicinal product in the European Union, the sponsor must obtain approval of a marketing authorization application (“MAA”). The way in which a medicinal product can be approved in the European Union depends on the nature of the medicinal product. As of January 31, 2020, the United Kingdom (UK)(“UK”) is no longer a member state of the EU, and therefore a separate MAA and approval will be required to market a medicinal product in the UK. The UK’s Medicines and Healthcare products Regulatory Agency (“MHRA”) has issued guidance regarding the requirements for licensing and marketing therapeutic drugs and biologics post-Brexit.

The centralized procedure results in a single marketing authorization granted by the European Commission that is valid across the European Union, as well as in Iceland, Liechtenstein, and Norway. The centralized procedure is compulsory for human drugs that are: (i) derived from biotechnology processes, such as genetic engineering, (ii) contain a new active substance indicated for the treatment of certain diseases, such as HIV/AIDS, cancer, diabetes, neurodegenerative diseases, autoimmune and other immune dysfunctions and viral diseases, (iii) officially designated “orphan drugs” (drugs used for rare human diseases) and (iv) advanced-therapy medicines, such as gene-therapy, somatic cell-therapy or tissue-engineered medicines. The centralized procedure may at the request of the applicant also be used for human drugs which do not fall within the above mentioned categories if the human drug (a) contains a new active substance which was not authorized in the European Community; or (b) the applicant shows that the medicinal product constitutes a significant therapeutic, scientific or technical innovation or that the granting of authorization in the centralized procedure is in the interests of patients or animal health at the European Community level.

Under the centralized procedure in the European Union, the maximum timeframe for the evaluation of a marketing authorization application by the European Medicines Agency or EMA,(“EMA”) is 210 days (excluding clock stops, when additional written or oral information is to be provided by the applicant in response to questions asked by the Committee for Medicinal Products for Human Use or CHMP)(“CHMP”)), with adoption of the actual marketing authorization by the European Commission thereafter. Accelerated evaluation might be granted by the CHMP in exceptional cases, when a medicinal product is expected to be of a major public health interest from the point of view of therapeutic innovation, defined by three cumulative criteria: the seriousness of the disease to be treated; the absence of an appropriate alternative therapeutic approach, and anticipation of exceptional high therapeutic benefit. In this circumstance, EMA ensures that the evaluation for the opinion of the CHMP is completed within 150 days and the opinion issued thereafter.

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The mutual recognition procedure or MRP,(“MRP”) for the approval of human drugs is an alternative approach to facilitate individual national marketing authorizations within the European Union. Basically, the MRP may be applied for all human drugs for which the centralized procedure is not obligatory. The MRP is applicable to the majority of conventional medicinal products, and is based on the principle of recognition of an already existing national marketing authorization by one or more member states. In the MRP, a marketing authorization for a drug already exists in one or more member states of the European Union and subsequently marketing authorization applications are made in other European Union member states by referring to the initial marketing authorization. The member state in which the marketing authorization was first granted will then act as the reference member state. The member states where the marketing authorization is subsequently applied for act as concerned member states. After a product assessment is completed by the reference member state, copies of the report are sent to all member states, together with the approved summary of product characteristics, labeling and package leaflet. The concerned member states then have 90 days to recognize the decision of the reference member state and the summary of product characteristics, labeling and package leaflet. National marketing authorizations within individual member states shall be granted within 30 days after acknowledgement of the agreement

Should any member state refuse to recognize the marketing authorization by the reference member state, on the grounds of potential serious risk to public health, the issue will be referred to a coordination group. Within a timeframe of 60 days, member states shall, within the coordination group, make all efforts to reach a consensus. If this fails, the procedure is submitted to an EMA scientific committee for arbitration. The opinion of this EMA committee is then forwarded to the Commission, for the start of the decision-making process. As in the centralized procedure, this process entails consulting various European Commission Directorates General and the Standing Committee on Human Medicinal Products or Veterinary Medicinal Products, as appropriate.

Rest of World Government Regulation

For countries outside of the United States and the European Union, such as countries in Eastern Europe, Latin America or Asia, the requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. In all cases, again, the clinical trials are conducted in accordance with GCP and the other applicable regulatory requirements.

If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension of clinical trials, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions, and criminal prosecution.

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Other Healthcare Laws

Although we currently do not have any products on the market, if our product candidates are approved in the United States, we will have to comply with various U.S. federal and state laws, rules and regulations pertaining to healthcare fraud and abuse, including anti-kickback laws and physician self-referral laws, rules and regulations. Violations of the fraud and abuse laws are punishable by criminal and civil sanctions, including, in some instances, exclusion from participation in federal and state healthcare programs, including Medicare and Medicaid. These laws include the following:

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Some state laws require pharmaceutical or medical device companies to comply with the relevant industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government in addition to requiring drug manufacturers to report information related to payments to physicians and other health care providers or marketing expenditures.

In November 2020, the Department of Health and Human Services (“DHHS”) finalized significant changes to the regulations implementing the Anti-Kickback Statute, as well as the Physician Self-Referral Law (Stark Law) and the civil monetary penalty rules regarding beneficiary inducements, with the goal of offering the healthcare industry more flexibility and reducing the regulatory burden associated with those fraud and abuse laws, particularly with respect to value-based arrangements among industry participants. As noted below under “Healthcare Reform,” however, those final rules may be potentially overturned under the Congressional Review Act following the change in control of the legislative and executive branches in January 2021.

State and foreign laws also govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts. We also may beare subject to, or may in the future become subject to, U.S. federal and state, and foreign laws and regulations imposing obligations on how we collect, use, disclose, store and process personal information. Our actual or perceived failure to comply with such obligations could result in liability or reputational harm and could harm our business. Ensuring compliance with such laws could also impair our efforts to maintain and expand our customer base and thereby decrease our future revenues.

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Pharmaceutical Coverage, Pricing, and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of products approved by the FDA and other government authorities. Sales of our products, when and if approved for marketing in the United States, will depend, in part, on the extent to which our products will be covered by third-party payors, such as federal, state, and foreign government healthcare programs, commercial insurance and managed healthcare organizations. The process for determining whether a payor will provide coverage for a product may be separate from the process for setting the price or reimbursement rate that the payor will pay for the product once coverage is approved. Third-party payors may limit coverage to specific products on an approved list, or formulary, which might not include all of the approved products for a particular indication. In addition, these third-party payors are increasingly reducing reimbursements for medical products, drugs and services. Furthermore, the U.S. government, state legislatures and foreign governments have continued implementing cost containment programs, including price controls, restrictions on coverage and reimbursement and requirements for substitution of generic products. Adoption of price controls and cost containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit our net revenue and results. Limited third-party reimbursement for our product candidates or a decision by a third-party payor not to cover our product candidates could reduce physician usage of our products once approved and have a material adverse effect on our sales, results of operations and financial condition.

In Europe and other countries outside of the United States, pricing and reimbursement schemes vary widely from country to country. Some countries provide that drug products may be marketed only after a reimbursement price has been agreed to. Some countries may require the completion of additional studies that compare the cost-effectiveness of a particular product candidate to currently available therapies. In some countries, cross-border imports from low-priced markets exert competitive pressure that may reduce pricing within a country. Any country that has price controls or reimbursement limitations for drug products may not allow favorable reimbursement and pricing arrangements.

Healthcare Reform

In the United States and some foreign jurisdictions, there have been, and continue to be, several legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of product and therapeutic candidates, restrict or regulate post-approval activities, and affect the ability to profitably sell product and therapeutic candidates that obtain marketing approval. The FDA’s and other regulatory authorities’ policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product and therapeutic candidates. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we otherwise may have obtained and we may not achieve or sustain profitability, which would adversely affect our business, prospects, financial condition and results of operations. Moreover, among policy makers and payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and/or expanding access.

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For example, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act or collectively(collectively, the ACA,“ACA”), was enacted in March 2010 and has had a significant impact on the health care industry in the U.S.United States. The ACA expanded coverage for the uninsured while at the same time containing overall healthcare costs. With regard to biopharmaceutical products, the ACA, among other things, addressed a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected, increased the minimum Medicaid rebates owed by manufacturers under the Medicaid Drug Rebate Program and extended the rebate program to individuals enrolled in Medicaid managed care organizations, established annual fees on manufacturers of certain branded prescription drugs, and created a new Medicare Part D coverage gap discount program. Additionally, on December 20, 2019, President Trump signed the Further Consolidated Appropriations Act for 2020 was signed into law (P.L. 116-94) thatand includes a piece of bipartisan legislation called the Creating and Restoring Equal Access to Equivalent Samples Act of 2019 or the “CREATES Act.” The CREATES Act aims to address the concern articulated by both the FDA and others in the industry that some brand manufacturers have improperly restricted the distribution of their products, including by invoking the existence of a REMS for certain products, to deny generic product developers access to samples of brand products. Because generic product developers need samples to conduct certain comparative testing required by the FDA, some have attributed the inability to timely obtain samples as a cause of delay in the entry of generic products. To remedy this concern, the CREATES Act establishes a private cause of action that permits a generic product developer to sue the brand manufacturer to compel it to furnish the necessary samples on “commercially reasonable, market-based terms.” Whether and how generic product developments will use this new pathway, as well as the likely outcome of any legal challenges to provisions of the CREATES Act, remain highly uncertain and its potential effects on future competition for COSELA or any of our other future commercial products are unknown.

As another example,Since the 2021 Consolidated Appropriations Act signed into law on December 27, 2020 incorporated extensive healthcare provisions and amendments to existing laws, including a requirement that all manufacturersenactment of drugs and biological products covered under Medicare Part B report the product’s average sales price, or ASP, to DHHS beginning on January 1, 2022, subject to enforcement via civil money penalties.  

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Since its enactment,ACA, there have been executive, judicial and Congressional challenges to certain aspects and as a result certain sections of the ACA have not been fully implemented or have been effectively repealed through Executive Orders and/or executive agency actions. However, following several years of litigation in the federal courts, in June 2021, the U.S. Supreme Court upheld the ACA when it dismissed a legal challenge to the ACA’s constitutionality. Further legislative and weregulatory changes under the ACA remain possible, although the Biden Administration has signaled that it plans to build on the ACA and expand the number of people who are eligible for health insurance subsidies under it. It is unknown what form any such changes or any law would take, and how or whether it may affect the biopharmaceutical industry as a whole or our business in the future. We expect there will be additional challenges and amendmentsthat changes or additions to the ACA, the Medicare and Medicaid programs, such as changes allowing the federal government to directly negotiate drug prices, and changes stemming from other healthcare reform measures, especially with regard to healthcare access, financing or other legislation in the future. Members of the US Congressindividual states, could have indicated that they may continue to seek to modify, repeal or otherwise invalidate all, or certain provisions of, the ACA. For example, the Tax Cuts and Jobs Act, or TCJA, was enacted in 2017 and, among other things, removed penalties, starting January 1, 2019, for not complying with the ACA’s individual mandate to carry health insurance, commonly referred to as the “individual mandate.” In December 2018, a U.S. District Court Judge in the Northern District of Texas ruled that the individual mandate was a critical and inseverable feature of the ACA, and therefore, because it was repealed as part of the TCJA, the remaining provisions of the ACA were invalid and the law in its entirety was unconstitutional. In December 2019, the U.S. Court of Appeals for the Fifth Circuit upheld the District Court ruling that the individual mandate was unconstitutional but remanded the case back to the District Court to determine whether other reforms enacted as part of the ACA but not specifically related to the individual mandate or health insurance could be severed from the rest of the ACA so as not to be declared invalid as well. On March 2, 2020, the United States Supreme Court granted the petitions for writs of certiorari to review this case and allocated one hour for oral arguments, which occurred on November 10, 2020. A decision from the Supreme Court is expected to be issued in spring 2021. It is unclear how this litigation and other efforts to repeal and replace the ACA will impact the implementation of the ACA, the pharmaceutical industry more generally, and our business. Complying with any new legislation or reversing changes implemented under the ACA could be time-intensive and expensive, resulting in a material adverse effect on our business.the health care industry in the United States.

In addition, other legislative changes have been proposed and adopted in the United States since the ACA that affect health care expenditures. These changes include aggregate reductions to Medicare payments to providers of up to 2% per fiscal year pursuant to the Budget Control Act of 2011, which began in 2013 and will remain in effect through 2030 unless additional Congressional action is taken. The Coronavirus Aid, Relief, and Economic Security Act or the CARES Act,(the “CARES Act”), which was signed into law on March 27, 2020 and was designed to provide financial support and resources to individuals and businesses affected by the COVID-19 pandemic, suspended the 2% Medicare sequester from May 1, 2020 through December 31, 2020, and extended the sequester by one year, through 2030, in order to offset the added expense of the 2020 cancellation. The 2021 Consolidated Appropriations Actsuspension was subsequently signed into law on December 27, 2020 and extends the CARES Act suspension period toextended through March 31, 2021.2022, with a reduction of the suspension to 1% sequester through June 30, 2022.

Moreover, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products. DHHS has solicited feedback on some of the various measures intended to lower drug prices and reduce the out of pocket costs of drugs and implemented others under its existing authority. For example, in May 2019, DHHS issued a final rule to allow Medicare Advantage plans the option to use step therapy for Part B drugs beginning January 1, 2020. This final rule codified a DHHS policy change that was effective January 1, 2019. As part of the Trump Administration’s so-called “Blueprint” to lower drug prices, DHHS and FDA also released on July 31, 2019 their Safe Importation Action Plan proposing two different pathways for the importation of foreign drug products. One pathway focuses on the importation of certain drugs from Canada, which required the agencies to go through notice-and-comment rulemaking, while the second pathway allows manufacturers to distribute their drugs manufactured abroad and was released as agency policy in an FDA guidance document first issued in December 2019. FDA’s notice of proposed rulemaking to implement a system whereby state governmental entities could lawfully import and distribute prescription drugs sourced from Canada was published at the end of December 2019 and in September 2020, the rulemaking was finalized by FDA. Those new regulations became effective on November 30, 2020, although the impact of such future programs is uncertain, in part because lawsuits have been filed challenging the government’s authority to promulgate them. The final regulations may also be vulnerable to being overturned by a joint resolution of disapproval from Congress under the procedures set forth in the Congressional Review Act, which could be applied to regulatory actions taken by the Trump Administration on or after August 21, 2020 (i.e., in the last 60 days of legislative session of the 116th Congress). Congress and the executive branch have each indicated that it will continue to seek new legislative and/or administrative measures to control drug costs, making this area subject to ongoing uncertainty. In addition, the probability of success of other policies enacted over the final months of the Trump Administration and their impact on the U.S. prescription drug marketplace is unknown. There are likely to be political and legal challenges associated with implementing these reforms as they are currently envisioned, and the January 20, 2021 transition to a new Democrat-led presidential administration created further uncertainty. Following his inauguration, President Biden took immediate steps to order a regulatory freeze on all pending substantive executive actions in order to permit incoming department and agency heads to review whether questions of fact, policy, and law may be implicated and to determine how to proceed.

Individual states in the United States have also increasingly passed legislation and implemented regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. In December 2020, the U.S. Supreme Court held unanimously that federal law does not preempt the states’ ability to regulate pharmaceutical benefit managers (PBMs)(“PBMs”) and other members of the health care and pharmaceutical supply chain, an important decision that may lead to further and more aggressive efforts by states in this area.

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We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative or executive action, either in the United States or abroad. We expect that additional state and federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, including COSELA and any future drug products for which we secure marketing approval.

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Manufacturing Requirements

We and our third-party manufacturers must comply with applicable cGMP requirements. The cGMP requirements include requirements relating to, among other things, organization of personnel, buildings and facilities, equipment, control of components and drug product containers and closures, production and process controls, packaging and labeling controls, holding and distribution, laboratory controls, records and reports, and returned or salvaged products. The manufacturing facilities for our products must meet cGMP requirements to the satisfaction of the FDA pursuant to a pre-approval inspection before we can use them to manufacture commercial products. We and our third-party manufacturers are also subject to periodic announced or for-cause unannounced inspections of facilities by the FDA and other authorities, including procedures and operations used in the testing and manufacture of our commercial products, if any, to assess our compliance with applicable regulations. Failure to comply with statutory and regulatory requirements subjects a manufacturer to possible legal or regulatory action, including, among other things, warning or other enforcement letters, voluntary corrective action, the seizure of products, injunctions, consent decrees placing significant restrictions on or suspending manufacturing operations, disgorgement of profits, and other civil and criminal penalties.

Other Regulatory Requirements

We are also subject to various laws and regulations regarding laboratory practices, the experimental use of animals, and the use and disposal of hazardous or potentially hazardous substances in connection with our research. In each of these areas, as above, the FDA has broad regulatory and enforcement authority, including, among other things, the ability to levy fines and civil penalties, suspend or delay issuance of approvals, seize or recall products, and withdraw approvals, any one or more of which could have an adverse effect on our ability to operate our business and generate revenues. Compliance with applicable environmental laws and regulations is expensive, and current or future environmental regulations may impair our research, development and production efforts, which could harm our business, operating results and financial condition.

Human Capital Management

As of December 31, 2020,2021, we employed 220238 employees, of which 217235 were full-time employees. A significant number of our management and professional employees have had prior experience with pharmaceutical, biotechnology or medical product companies. None of our employees are represented by a labor union or covered under a collective bargaining agreement. Management considers relations with our employees to be good.

Our approach to human capital managementhow we recruit, develop, retain and manage our talent is driven by our values statement: Making an impact through innovation, inclusion, and inspiration. Our values are at the core of who we are as an organization, and what drive us to envision a brighter future for the patients and families affected by genetically defined diseases. In order for uswe serve. Critical to achieving our strategic imperatives is our ability to build a world-class organization to develop a new era of nucleic acid medicines, we must build and maintainretain an exceptional team in which each member plays a unique and important role,role. We value diversity, inclusion, and embracesocial responsibility where our employees have a forward-thinking philosophy that extends beyondstrong sense of belonging and contributing, while being empowered to make a real difference.  In 2021, we updated our work,Nominating and Corporate Governance Committee charter to how we are buildingreflect the Nominating and Corporate Governance Committee’s oversight of our culturestrategies and benefits.policies related to our people and diversity, equity and inclusion (“DEI”), in addition to the Nominating and Corporate Governance Committee’s oversight of our environmental, social and governance (“ESG”) strategy, initiatives and policies.

We recognize that maintaining an engaged and top-notchhigh-performing workforce andwho share a connection with the communities we serve is critical to our success. Comradery and cohesion are at the core of who we are as a company, and are integral facets of our human capital management strategy. Whether it is coming together throughout the year to connect at our town halls or participating in a global fitness challenge to support the health and well-being of our employees, we take a team approach to our work. We are inspired by each other and the possibilities of what we can achieve together.

We understand that in order to drive innovation, we must continuously improve our human capital managementpeople strategies and find ways to foster engagement and growth within our organization. To this end, below are some of our initiatives:

Employee Engagement:Engagement: We embrace the idea that our employees do their best work when they have equity ownership in the business.  Having an engaged and dedicated workforce is essential for us to achieve our goals. Employee engagement ensures that our employees feel passionate about the work they are doing, and with this commitment, we recognize that this is when results happen. It is more apparent than ever that we are all in this together, and as a company, we need to set up our employees for success and continue to cultivate their engagement with our company. We regularly conduct an annual employee engagement surveysurveys as a means of measuring employee engagementengaging with employees and satisfaction, as wellgaining their insights. We use the data and input as a tool for improving our human capital strategies in the year ahead.resources management going forward. Engagement is also directly correlated to the interactions our employees have with each other and their teams. Our Wave Activities Committee is a cross-functional team dedicated to organizing activities, such as themed social gatherings, charity and volunteer opportunities, and health and wellness events, thatwhich enrich our culture and bring employees together. We also work to ensure that we

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are deeply aligned onwith our corporate goals as a company, that functional goals are clear and transparent, and that employees understand how their work contributes to the company’s success.

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Employee Health and Safety:Safety:  Compliance with environmental, health and safety (“EH&S”) laws and regulations underliesforms the basis of the EH&S policy and programs we have in place.place, which include occupational health and safety measures that apply to all of our employees, contractors and visitors. These programs detail the proactive, risk-based approach that we take to prevent workplace injuries and protect the health and safety of our employees and the communities around us. We have implemented an EH&S management system to monitor and track the effectiveness of our programs, ensure EH&S compliance, respond to incidents and manage corrective actions to reinforce safeguards. Our training programs provide training to our employees that is commensurate with their level of risk exposure and are designed to ensure that employees have the knowledge and equipment available to mitigate risk. Our cross-functional Safety Committee meets monthly to discuss any concerns and ways to improve our EH&S programs. Employees are also required to report any incidents, no matter how small, and are encouraged to voice any health or safety concerns to management or a member of our EH&S team. As we continue to monitor the global spread of COVID-19 situation, we have implemented and will continue to implement measures designed to ensuresafeguard the health and safety of our employees and our patients.patients, including COVID-19 testing. We formed a COVID-19 Response Team, whichresponse team, a business continuity planning team and a “future of work” team that is continuously evaluating the guidance from federal and local authorities and has created strict polices and guidelines that putcontinue to ensure our employee’semployees’ health and safety comes first. In October 2021, we implemented a mandatory COVID-19 vaccination policy.The EH&S management system incorporates processes to proactively assess risks to the health and safety of our employees and the community, as well as tracking compliance, incidents, inspections, and corrective actions. Our training program provides enhanced training to individuals that is parallel to the level of risk exposure to ensure that employees always have the knowledge and equipment at hand to mitigate risk.

Professional Development Programs and Opportunities: Our greatest asset isOpportunities: Employees are our employeesmost valuable resource, and we aspire to provide them with opportunities so that they can continue to grow and excel withinin their field,functions and our company. Professional growth of our employees leads to engagement and development, and allows us to leverage opportunities so we canto hire and promote key talent from within.within our organization. We have also implemented a personal development plan program, along withand leadership and management development programs. Through development planning, we strive for employees at all levels to focus on strengthening the skills required in their current role or a potential futureand potentially their next role. We conduct formal annual performance reviews for all employees, but, as importantly, we are focused on building a culture of continuous coaching, feedback and open communication between managers and their direct reports throughout the entire year. We provide managers and employees with training on how to conduct effective forward-looking performance conversations and to set effective goals that are realistic,specific, measurable, attainable, relevant and timebound (SMART). We provide our employees with unlimited access to LinkedIn Learning, to advance their professional development, interests and goals. Another example where we provide company-wide leadership and development opportunities is through the Wave Learning Series, which was developed to build awareness of all functional areas, at Wave,special areas of interest or importance, timely subject matters and to expand knowledge of industry trends and other matters of interest and relevance within the biopharmaceutical industry. The Wave Learning Series is conducted through company-wide presentations by employees at various levels, providing opportunities for development and cross-functional exposure for our employees. To further assist our employees, we also offer all full-time employees the option to participate in our Education Assistance Program, where we reimburse employees for tuition and eligible expenses.

Health and Well-Being:Well-Being: We believe that the overall well-being of our employees and ensuring that their basic health and wellness needs are met, is fundamental for us to achieve success as a company. In our ongoing efforts to prioritize wellness initiatives, we understand that a key part of this includes providing our employees with access to mental health, behavioral health, and/or substance abuse services through our medical plans. We provide an Employee Assistance Program (“EAP”), as a cost-free benefit, which is available to help employees and their household members confidentially manage everyday life, work challenges, stress, and other personal issues, by providing consultation, referrals and resources.resources, along with ongoing webinars on various work-life, mental health and wellness topics for employees.  In 2020, in lightaddition, we understand that workplace flexibility is an important component to our employees’ well-being. Throughout the COVID-19 pandemic, safeguarding employee and patient health has been our top priority, as we advance our business through the research and development of our therapeutic candidates. During the height of the COVID-19 global pandemic, we partneredimplemented procedures to protect our workforce in manufacturing and laboratory operations, which included mandating a work-from-home policy for most employees. Prioritizing employee safety while achieving our goals has provided us with a greater appreciation for workplace flexibility, which keeps our EAP provider to provideemployees engaged and motivated, while also creating a seriessense of virtual meetings where employees could discuss the challengestrust throughout our organization.

Diversity, Equity and successes they have had during these unprecedented times, and discuss the importance of staying resilient while facing uncertainty.

Diversity and Inclusion:Inclusion (“DEI”): Our commitment to maintaining a top-performing company means investing in and creating ongoing opportunities for employee development in a diverse and inclusive environment.workplace. We provide equal employment opportunities without regard to race, color, religion, sex, national origin, age, disability or genetics. In 2021, we formalized our DEI efforts through various initiatives, including the formation of a DEI Steering Group to be more intentional about creating and maintaining a diverse, inclusive, equitable, culturally competent and supportive environment for all of our employees and stakeholders. Some of our preliminary DEI initiatives include creating opportunities for our employees to be engaged with our DEI initiatives through participation in a cultural assessment survey and implementing a DEI strategy with short-, medium- and long-term goals. We believe that a diverse and inclusive workforce not only positively impacts our performance, fosters innovation and inspires us to achieve greater results, increasesresults.  In addition to this, our collective capabilities and strengthensintentional focus on DEI continues to strengthen our culture but it also cultivatesand helps ensure that we continue to cultivate an essential pipelineeffective next generation of experienced leaders and managers necessary to execute on our mission and plans for management.ambitious growth. Hiring for diversity of thought, background and experience, and diversity of personal characteristics such as gender, race and ethnicity, among many others, is intentional, at Wave and continues to be an area of focus for us as we build and grow our workforce. Despite the historical lack of institutional emphasis on the importance of girls and women focusing on education in science, technology, engineering and mathematics (“STEM”) and the resulting disproportionate occupation by men in the STEM-educated talent pool, the Company haswe have prioritized and hired a gender diverse workforce. As of December 31, 2020,2021, women makemade up approximately 51%52% of our global workforce and constitute approximately 43%49% of management.management (defined as director level and above). We are also committed to building a racially and ethnically diverse workforce. As of December 31, 2020,2021, racially diverse employees (those self-identifyingself-

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identifying as Black or African American, Hispanic or Latino,Latinx, Asian, or being of two or more races) make up approximately 42%36% of our global workforce and approximately 21%30% of management (12%(22% of our employees did not provide us with this information).  In addition, we continue to partner with Project Onramp, which is an organization that is working to bridge the opportunity gap for Massachusetts college students in underserved and minority communities. Through this partnership, we provide students with summer internships.

Community Outreach and Engagement:Engagement: Our community engagement activities are focused on seeking to better understand the lives of people living with rare disease and identifying opportunities to support the rare disease community. We believe that partnering with, and understanding the lives of patients and their families and caregivers, differentiates Waveus and enhances our ability to discover and develop potential therapies. Through collaboration with patients, families and advocacy organizations, face-to-face meetings, and participation in patient-focused conferences and community events, we aim to broaden our understanding of the needs of patients and families and incorporate those critical learnings into every aspect of our company. These insights inform the design and execution of our clinical trials, the enrichment of our corporate culture, and the development of programs and services that make a positive impact on people’s lives. Employee volunteerism is another important component of our community engagement initiatives. We partner with advocacy and service organizations to provide opportunities for employees to contribute directly to our local communities.communities, including through our Wave Service Day. By participating in a broad range of volunteer activities, our employees donate time and resources to support patients and families in the rare disease community.community and beyond.

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Rewards and Recognition:Recognition: We have a multi-tiered awards programs,program, including peer-to-peer recognition, thatwhich our employees use to recognize and reward one another for their contributions and achievements, taking into consideration the combination of employees who best exemplify our values and the achievement of results. We believe that providing a rewards program not only increases engagement and performance, but meaningfully recognizes those employees who go above and beyond to positively impact our company and culture.  In 2021, we developed a team rewards and recognition program to provide another opportunity to recognize and reward collaborative teamwork.

Compensation, Equity and Benefits:Benefits (Total Rewards): Compensation programs are one of the most powerful tools available to companies to attract, retain and motivate employees, as well as align their interests with those of shareholders.  We have designed a broad-based compensation program that is designed to attract, retain and motivate our employees, to deliverwhile driving sustainable long-term value.value creation. We seek to deliver performance-driven, market competitive reward opportunities commensurate with company and individual performance.  All of our employees of Wave receive competitive base salaries, cash bonuses, new hire equity grants and annual long-term incentive grants, in addition to our generous benefits package. We believe that providing employees with an ownership interest in the Company willour company through grants of equity awards, further strengthenstrengthens the level of employee engagement. Furthermore, equity awards help align the interests of our employees with the long-term interests of our shareholders.  In addition, we have an Employee StockShare Purchase Plan (“ESPP”), which provides our employees with an opportunity to purchase shares of our Company at a 15% discount to the market price.

Offering a highly competitive, industry-leading, benefits package is another integral piece of our compensation program.total rewards package and differentiated employee value proposition. Notably, we provide our employees with access to choice and offer employees a very progressive health insurance package, with no premiums. We also maintainoffer a 401(k) plan with matching contributions for all eligible employees. We were named a best-in-class employer, scoring in the top quartile of large and midsize employers who participated in Gallagher’s 2021 Benefits Strategy & Benchmarking Survey. We were recognized for providing innovative solutions that all ofare key to attracting, engaging and motivating employees, including (i) our employees are eligible to participate in.excellent benefits and compensation programs and strategies; (ii) our employee well-being approach and strategy; (iii) our health plan and how we have managed this over time; and (iv) internal communications and education around our total rewards strategy.

We will continue to evolve and strengthen our human capital management strategies relating to talent, while furthering our investment in our employees, culture, community partnerships and outreach, and other human capital measures.

Corporate Information

We were incorporated under the name Wave Life Sciences Pte. Ltd. (Registration No.: 201218209G) under the laws of Singapore on July 23, 2012. On November 16, 2015, we closed our initial public offering. In preparation for our initial public offering, on November 5, 2015, Wave Life Sciences Pte. Ltd. converted from a private limited company to a public limited company known as Wave Life Sciences Ltd. (“Wave”). Wave has four wholly-owned subsidiaries: Wave Life Sciences USA, Inc. (“Wave USA”), a Delaware corporation (formerly Ontorii, Inc.); Wave Life Sciences Japan, Inc. (“Wave Japan”), a company organized under the laws of Japan (formerly Chiralgen., Ltd.); Wave Life Sciences Ireland Limited (“Wave Ireland”), a company organized under the laws of Ireland; and Wave Life Sciences UK Limited (“Wave UK”), a company organized under the laws of the United Kingdom.

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Our registered office is located at 7 Straits View #12-00, Marina One East Tower, Singapore 018936, and our telephone number at that address is +65 6236 3388. Our principal office for Wave USA is located at 733 Concord Avenue, Cambridge, MA 02138, and our telephone number at that address is +1-617-949-2900. Our registered office for Wave Japan is 2438 Miyanoura-cho, Kagoshima-shi, Kagoshima pref. 891-1394, Japan. Our registered office for Wave Ireland is One Spencer Dock, North Wall Quay, Dublin 1, D01 X9R7, Ireland. Our registered office for Wave UK is 1 Chamberlain Square CS, Birmingham B3 3AX, United Kingdom.

Information Available on the Internet

Our Internet website address is http://www.wavelifesciences.com. The information contained on, or that can be accessed through, our website is not a part of, or incorporated by reference in, this Annual Report on Form 10-K.10-K or our other filings with the SEC. We have included our website address in this Annual Report on Form 10-K solely as an inactive textual reference. We make available free of charge through our website our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to those reports filed or furnished pursuant to Sections 13(a) and 15(d) of the Exchange Act. We make these reports available through the “For Investors & Media – Financial Information”SEC Filings” section of our website as soon as reasonably practicable after we electronically file such reports with, or furnish such reports to, the Securities and Exchange Commission (“SEC”). We also make available, free of charge on our website, the reports filed with the SEC by our executive officers, directors and 10% shareholders pursuant to Section 16 under the Exchange Act as soon as reasonably practicable after copies of those filings are filed with the SEC. You can review our electronically filed reports and other information that we file with the SEC on the SEC’s website at http://www.sec.gov.

In addition, we regularly use our website to post information regarding our business and governance, and we encourage investors to use our website, particularly the information in the section entitled “For Investors & Media,” as a source of information about us.

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Risk Factors

You should carefully consider the following risk factors, in addition to the other information contained in this Annual Report on Form 10-K, including the section of this report titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our financial statements and related notes. If any of the events described in the following risk factors and the risks described elsewhere in this Annual Report on Form 10-K occurs, our business, operating results and financial condition could be seriously harmed and the trading price of our ordinary shares could decline. This Annual Report on Form 10-K also contains forward-looking statements that involve risks and uncertainties. Our actual results could differ materially from those anticipated in the forward-looking statements as a result of factors that are described below and elsewhere in this Annual Report on Form 10-K.

Risks Related to Our Financial Results and Capital Requirements

We are a clinical-stage genetic medicines company with a history of losses, and we expect to continue to incur losses for the foreseeable future, and we may never achieve or maintain profitability.

We are a clinical-stage genetic medicines company and have incurred significant operating losses since our incorporation in 2012. Our net loss was $149.9$122.2 million and $193.6$149.9 million for the fiscal years ended December 31, 20202021 and 2019,2020, respectively. As of December 31, 20202021 and 2019,2020, we had an accumulated deficit of $683.3$805.5 million and $533.4$683.3 million, respectively. To date, we have not generated any product revenue. Substantially all of our losses have resulted from expenses incurred in connection with our research and development programs and from general and administrative costs associated with our operations.

We currently have no products on the market and expect that it may be many years, if ever, before we have a product candidate ready for commercialization. WeOur lead clinical development programs are conducting clinical trials of our two most advanced programs indesigned to treat genetic diseases within the CNS, including ALS, FTD, HD and expect to deliver data from those trials at the end of the first quarter of 2021. Also in 2021,DMD, and we expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry to enable decision making. With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat AATD. We expect to select an AATD AIMer development candidate and initiate dosingIND-enabling toxicology studies in three new clinical trials with compounds containing our novel PN backbone chemistry modifications, including WVE-003 in HD, WVE-004 in ALS and FTD, and WVE-N531 in DMD. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating our ophthalmology programs and continue to explore additional targets in neurology and hepatic disorders.

the third quarter of 2022. We have not generated, and do not expect to generate, any product revenue for the foreseeable future, and we expect to continue to incur significant operating losses for the foreseeable future due to the cost of research and development, manufacturing, preclinical studies and clinical trials and the regulatory review process for product candidates. The amount of future losses is uncertain. To achieve profitability, we must successfully develop product candidates, obtain regulatory approvals to market and commercialize product candidates, manufacture any approved product candidates on commercially reasonable terms, establish a sales and marketing organization or suitable third-party alternatives for any approved product and raise sufficient funds to finance our business activities. We may never succeed in these activities and, even if we do, may never generate revenues that are significant or large enough to achieve profitability. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company could also cause our shareholders to lose all or part of their investment.

We will require substantial additional funding, which may not be available on acceptable terms, or at all.

We have used substantial funds to develop our programs and PRISM, our proprietary discovery and drug development platform, and will require substantial funds to conduct further research and development, including preclinical studies and clinical trials of our product candidates, seek regulatory approvals for our product candidates and manufacture and market any products that are approved for commercial sale. We believe that our existing cash and cash equivalents will be sufficient to fund our operations for at least the next 12 months.

Our future capital requirements and the period for which we expect our existing resources to support our operations may vary significantly from what we expect. We do not expect to realize any appreciable revenue from product sales or royalties in the foreseeable future, if at all. Our revenue sources will remain extremely limited unless and until our product candidates complete clinical development and are approved for commercialization and successfully marketed. Because we cannot be certain of the length of time or activities associated with successful development and commercialization of our product candidates, we are unable to estimate the actual funds we will require to develop and commercialize them.

Our future capital requirements will depend on many factors, including, but not limited to, the following:

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To date, we have primarily financed our operations through sales of our securities and our collaborations with third parties. As a privately held company, we received an aggregate of $89.3 million from the sale of our securities. As a publicly traded company, through March 3, 2021,2, 2022, we have received an aggregate of $484.5 million in gross proceeds from public offerings of our securities, or approximately $449.4 million in net proceeds, including gross proceeds of $111.9 million from our November 2015 initial public offering, $100.0 million from our April 2017 follow-on public offering, $172.6 million from our January 2019 follow‑on public offering, and $100.0 million from our September 2020 follow-on public offering.proceeds. On or about March 2, 2020,3, 2022, we filedplan to file a post-effective amendment to ournew universal shelf registration statement on Form S-3 (the “Registration Statement”) becausewith the SEC, pursuant to which we no longer qualified as a “well-known seasoned issuer” as such term is defined in Rule 405 of the Securities Act of 1933, as amended. The Registration Statement includes a base prospectus covering the offering, issuance andwill register for sale of up to $340.0$500.0 million in the aggregateof any combination of our ordinary shares, debt securities, warrants, rights and/or units from time to time and rights, separately orat prices and on terms that we may determine, which we refer to as units or any combination thereof, in one or more offerings.the “2022 Form S-3.” The Registration Statement also2022 Form S-3 includes a prospectus covering up to an aggregate of $190.0approximately $132.0 million in ordinary shares remaining that we may issue and sell from time to time, through Jefferies LLC acting as our sales agent, pursuant to the open market sales agreement that we entered into with Jefferies LLC in May 2019 forhave not yet been issued or sold under our at-the-market equity program.program with Jefferies LLC. As of March 3, 2021,2, 2022, we have received $60.9approximately $118.0 million in gross proceeds from our at-the-market equity program, under the sales agreement prospectus pursuant to the Registration Statement. In addition,and we have received $40.0$292.5 million under our collaborationcollaborations with Pfizer and received (or are due to receive) an aggregate of $230.0 million in equity investments, upfront and committed payments under our collaboration with Takeda,third parties, exclusive of any potential future milestone and royalty payments. We intend to seek additional funding in the future through collaborations, public or private equity offerings or debt financings, credit or loan facilities or a combination of one or more of these financing sources.

Our ability to raise additional funds will depend on financial, economic and other factors, many of which are beyond our control. For example,We may seek access to the capital and credit markets for working capital, capital expenditure, and other business initiatives. The capital and credit markets are experiencing, and in connection with our data readouts in December 2019, our stock price declined significantly,the past have experienced, extreme volatility and disruption, which may make it more difficultlead to uncertainty and liquidity issues for us to obtainboth borrowers and investors. In the event of adverse market conditions, or other factors, additional funding on terms as favorable as those prior to our stock price decline. Additional funds may not be available to us on acceptable terms or at all. If we raise additional funds by issuing equity or convertible debt securities, our shareholders will suffer dilution and the terms of any financing may adversely affect the rights of our shareholders. In addition, as a condition to providing additional funds to us, future investors may demand, and may be granted, rights superior to those of existing shareholders. Debt financing, if available, may involve restrictive covenants limiting our flexibility in conducting future business activities, and, in the event of insolvency, debt holders would be repaid before holders of equity securities received any distribution of corporate assets.

If we are unable to obtain funding on a timely basis or on acceptable terms, we may have to delay, limit or terminate our research and development programs and preclinical studies or clinical trials, limit strategic opportunities or undergo reductions in our workforce or other corporate restructuring activities. We also could be required to seek funds through arrangements with collaborators or others that may require us to relinquish rights to some of our product candidates or technologies that we would otherwise pursue on our own.

Our management has broad discretion over the use of proceeds received from sales of our securities and our collaborations with third parties and the proceeds may not be used effectively.

Our management has broad discretion as to the use of proceeds we receive from conducting sales of our securities and our collaborations with third parties and could use the proceeds for purposes other than those contemplated at the time of such transactions. It is also possible that the proceeds we have received, or may receive, from securities sales and collaborations will be invested in a way that does not yield a favorable, or any, return for us.

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Our short operating history may make it difficult for shareholders to evaluate the success of our business to date and to assess our future viability.

We are a clinical-stage genetic medicines company with a limited operating history. We commenced active operations in 2012. Our operations to date have been limited to organizing and staffing our company, research and development activities, manufacturing, preclinical and clinical development, patient advocacy activities, business planning and raising capital. Prior Our lead clinical development programs are designed to 2017, all of our product candidates were intreat genetic diseases within the preclinical development stage. We are conducting clinical trials of our two most advanced programs inCNS, including ALS, FTD, HD and expect to deliver data from those trials at the end of the first quarter of 2021. Also in 2021,DMD, and we expect to share clinical

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data in 2022 to provide insight into the clinical effects of PN chemistry to enable decision making. With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat AATD. We expect to select an AATD AIMer development candidate and initiate dosingIND-enabling toxicology studies in three new clinical trials with compounds containing our novel PN backbone chemistry modifications, including WVE-003the third quarter of in HD, WVE-004 in ALS and FTD, and WVE-N531 in DMD. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating our ophthalmology programs and continue to explore additional targets in neurology and hepatic disorders.2022. We have not yet demonstrated our ability to successfully complete pivotal clinical trials, obtain marketing approvals, or conduct sales and marketing activities necessary for successful product commercialization. We have limited experience manufacturing our products at commercial scale or arranging for a third party to do so on our behalf. Typically, it takes many years to develop and commercialize a therapeutic from the time it is discovered to when it is available for treating patients. Further, drug development is a capital-intensive and highly speculative undertaking that involves a substantial degree of risk. You should consider our prospects in light of the costs, uncertainties, delays and difficulties frequently encountered by biotechnology companies in the early stages of clinical development, such as ours. Any predictions about our future success or viability may not be as accurate as they could be if we had a longer operating history or a history of successfully developing and commercializing pharmaceutical products.

We, or third parties upon whom we depend, may face risks related to health epidemics, including the novel coronavirus (COVID-19) pandemic and variants thereof, which may delay our ability to complete our ongoing clinical trials, initiate additional clinical trials, delay regulatory activities and have other adverse effects on our business and operations.

Since December 2019, multiple countries throughout the world and their economies, including the United States, have been subject to intermittent shutdowns and adversely affected by the COVID-19 global pandemic. To date, responsive measures such as social distancing, work-from-home policies, travel bans and quarantines have been implemented in many countries throughout the world, including the United States. We are in the midst of the global pandemic; therefore, we are continuing to evaluate the situation and the extent to which these responsive measures may materially and adversely affect our business operations and financial condition.

As a clinical-stage company with multiple programs and multiple clinical trials currently underway, the pandemic is impacting the execution of our clinical trials. We have clinical trial sites located in countries that have been affected by COVID-19 and variants thereof. Clinical site initiation and patient enrollment has been delayed due to prioritization of hospital resources in favor of COVID-19 patients and difficulties in recruiting clinical site investigators and clinical site staff. Some patients have not bebeen able to comply with clinical trial protocols caused by quarantines impeding patient movement and interrupting healthcare services,travel or patients may not be willing to travelgain access to clinical trial sites.sites due to local restrictions. Similarly, our ability to recruit and retain patients and principal investigators and site staff who, as healthcare providers, may have heightened risk of exposure to COVID-19, has been negatively impacted, which has delayed the timelines of our clinical trial operations. We are continuing to experience delays and disruptions in our clinical trials and preclinical studies due to resource constraints at contract research organizations and vendors along their supply chain. We may also experience interruption of key clinical trial activities, such as on-site clinical trial site data monitoring, due to limitations on travel imposed or recommended by federal or state governments, employers and others or interruption of clinical trial subject visits and study procedures (particularly any procedures that may be deemed non-essential), which may ultimately impact the integrityextent of subject data and clinical trial endpoints.missing data.

The COVID-19 pandemic has affected and may continue to affect the operations of the FDA, EMA and other regulatory authorities, which could result in delays of reviews and approvals, including with respect to our product candidates. If regulatory matters resulting from COVID-19 continue to prevent regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, it could impact the ability of regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

We rely upon third parties for many aspects of our business, including the raw materials used to make our product candidates and the conduct of our clinical trials and preclinical studies. While we have built up inventory to assist us through this uncertain operating environment, our suppliers may be disrupted now or in the future, which may affect our ability to procure items that are essential for our research and development activities and may cause pricing increases, inflation, and significant disruptions to our business.

We have implemented procedures to protect our workforce in manufacturing and laboratory operations, including implementing a mandatory COVID-19 vaccination policy in October 2021, while ensuring appropriate remote working protocols have been implemented for our employees who can work from home. The spread of COVID-19 and the responsive measures taken to date have limited our access to our facilities and caused the majority of our employees to work from home. We continue to monitor the global spread of COVID-19 and the response of international, national and local authorities, and

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have implemented and will continue to implement measures that we believe are appropriate and necessary for our business and the safety of our employees. In response to theseThese public health directives and orders we have implemented a work-from-home policy for our employees. The effects of the executive order, the stay-at-home advisory and our work-from-home policy may negatively impact productivity, disrupt our business and delay our clinical programs and timelines, the magnitude of which will depend, in part, on the length and severity of the restrictions and other limitations on our ability to conduct our business in the ordinary course. The increase in working remotely has increased our cybersecurity risk, has created data accessibility concerns, and has made us more susceptible to communication disruptions. In addition, as a result of potential shelter-in-place orders or other mandated travel restrictions, our on-site staff conducting research and development and manufacturing activities have experienced difficulties and delays in accessing our laboratories or manufacturing space.

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Our future capital requirements depend on many factors, including the continued uncertainty and duration of the COVID-19 pandemic. As a result, we may face difficulties raising capital through sales of our securities or such sales may be on unfavorable terms.

The COVID-19 global pandemic, including any emerging variants of COVID-19, is continuing to evolve rapidly and is subject to change. While we are adapting our processes to lessen the impact that COVID-19 may have on our business, we do not yet know the full extent of delays or long-term impacts on our business, our clinical trials, healthcare systems or the global economy. These impacts are highly uncertain and cannot be predicted with confidence, such as variants of the virus that may evolve, the duration of the outbreak, travel restrictions and actions to contain the outbreak or treataddress its impact, such as social distancing and quarantines or lock-downs in the United States and other countries, business closures or business disruptions and the effectiveness of actions taken in the United States and other countries to contain and treat the disease. These effects may materially adversely affect our business, financial condition, results of operations, and prospects.

Risks Related to the Discovery, Manufacturing, Development and Commercialization of Our Product Candidates

The approach we are taking to discover and develop oligonucleotides is novel and may never lead to marketable products.

We have concentrated our efforts and research and development activities on oligonucleotides and enhancing PRISM, our proprietary discovery and drug development platform. PRISM enables us to target genetically defined diseases with stereopure oligonucleotides across multiple therapeutic modalities. Our future success depends on the successful development of stereopure oligonucleotides and the effectiveness of PRISM. The scientific discoveries that form the basis for our efforts to discover and develop new product candidates, including our discoveries about the relationships between oligonucleotide stereochemistry and pharmacology, are relatively new. PRISM combines our unique ability to control backbone stereochemistry to create stereopure oligonucleotides and our deep knowledge of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key properties. The scientific evidence to support the feasibility of developing medicines based on these discoveries is limited. Skepticism as to the feasibility of developing oligonucleotides generally has been, and may continue to be, expressed in scientific literature. In addition, decisions by other companies with respect to their oligonucleotide development efforts may increase skepticism in the marketplace regarding the potential for oligonucleotides.

A number of clinical trials for oligonucleotide products conducted by other companies have not been successful, but some have received regulatory approval. The pharmacological properties ascribed to the investigational compounds we are testing in laboratory studies may not be positively demonstrated in clinical trials in patients, and they may interact with human biological systems in unforeseen, ineffective or harmful ways. For example, in December 2019,our first three clinical programs contained our first-generation chemistry, all of which we discontinued developmentfollowing receipt of suvodirsen for patients with DMD based on the interim analysisnegative clinical data. By contrast, all of the Phase 1 open-label extension (OLE) study.our current product candidates contain our next-generation PN backbone chemistry modifications. If our product candidates prove to be ineffective, unsafe or commercially unviable, PRISM and our pipeline would have little, if any, value, which would substantially harm our business, financial condition, results of operations and prospects. In addition, our approach, which focuses on using oligonucleotides for drug development, as opposed to multiple or other, more advanced proven technologies, and new products and technologies that may enter the market, may expose us to additional financial risks and make it more difficult to raise additional capital if we are not successful in developing one or more oligonucleotides that receive regulatory approval.

Because we are developing oligonucleotides, which are considered a relatively new class of drugs, there is increased risk that the outcome of our clinical trials will not be sufficient to obtain regulatory approval.

The FDA and comparable ex-U.S. regulatory agencies have relatively limited experience with oligonucleotides, which may increase the complexity, uncertainty and length of the regulatory review process for our product candidates. To date, the FDA has approved only 1113 oligonucleotides for marketing and commercialization. Even though the FDA in January 2021 issued a draft guidance document relating to IND submissions for individualized antisense oligonucleotide drugs for severely debilitating or life-threatening genetic diseases (“n of 1” guidance), the FDA and its foreign counterparts have not yet established any definitive policies, practices or guidelines specifically in relation to the development considerations for these drugs.oligonucleotide drugs for larger populations. The general lack of policies, practices or guidelines specific to oligonucleotides may hinder or slow review by the FDA of any regulatory filings that we may submit. Moreover, the FDA may

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respond to these submissions by defining requirements we may not have anticipated. Such responses could lead to significant delays in the development of our product candidates. In addition, because there may be approved treatments for some of the diseases for which we may seek approval, in order to receive regulatory approval, we may need to demonstrate through clinical trials that the product candidates we develop to treat these diseases, if any, are not only safe and effective, but safer or more effective than existing products. Furthermore, in recent years, there has been increased public and political pressure on the FDA with respect to the approval process for new drugs, and the FDA’s standards, especially regarding drug safety, appear to have become more stringent. As a result of the foregoing factors, we may never receive regulatory approval to market and commercialize any product candidate.

Even if we obtain regulatory approval, the approval may be for disease indications or patient populations that are not as broad as we intended or desired or may require labeling that includes significant use or distribution restrictions or safety warnings. We may be

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required to perform additional or unanticipated clinical trials to obtain regulatory approval or be subject to additional post-marketing studies or other requirements to maintain such approval. As a result, we may never succeed in developing a marketable product, we may not become profitable and the value of our ordinary shares could decline.

Our preclinical studies and clinical trials may not be successful. If we are unable to commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

We have a robust and diverse pipeline of PN-modified, stereopure oligonucleotides, including our clinical silencing and splicing programs as well as our AIMers. Our lead clinical development programs are conducting clinical trials of our two most advanced programs indesigned to treat genetic diseases within the CNS, including ALS, FTD, HD and expect to deliver data from those trials at the end of the first quarter of 2021. Also in 2021,DMD, and we expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry to enable decision making. With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat AATD. We expect to select an AATD AIMer development candidate and initiate dosingIND-enabling toxicology studies in three new clinical trials with compounds containing our novel PN backbone chemistry modifications, including WVE-003 in HD, WVE-004 in ALS and FTD, and WVE-N531 in DMD. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating our ophthalmology programs and continue to explore additional targets in neurology and hepatic disorders. the third quarter of 2022. However, we currently have no products on the market. We have invested a significant portion of our efforts and financial resources in the identification and preclinical and clinical development of our oligonucleotides, the development of PRISM, including our ADAR editing capability, and our novel PN backbone chemistry modifications, and the continued growth of our manufacturing capabilities. Our ability to generate product revenue, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of our product candidates. Our success will depend on several factors, including the following:

If we do not achieve one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize our product candidates, which would materially harm our business.

We may not be able to conduct clinical trials successfully due to various process-related factors that could negatively impact our business plans.

The successful initiation and completion of any of our clinical trials, within timeframes consistent with our business plans, is dependent on various factors, which include, but are not limited to, our ability to:

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If we are not able to manage the clinical trial process successfully, our business plans could be delayed or be rendered unfeasible for us to execute within our planned or required time frames, or at all.

If we cannot successfully manufacture our product candidates for our research and development and preclinical activities, or manufacture sufficient amounts of our product candidates to meet our clinical requirements and timelines, our business may be materially harmed.

In order to develop our product candidates, apply for regulatory approvals and commercialize our product candidates, we will need to develop, contract for, or otherwise arrange for the necessary manufacturing capabilities. In September 2016, we entered into a lease for a multi-use facility of approximately 90,000 square feet in Lexington, Massachusetts to provide internal cGMP manufacturing capabilities and increase control and visibility of our drug substance supply chain, and we began cGMP manufacturing in this facility at the beginning of 2018. This facility supplements our existing Cambridge, Massachusetts laboratory and office space headquarters, enhances our ability to secure drug substance for current and future development activities and may provide commercial-scale manufacturing capabilities. However, while we have established and continue to enhance our internal cGMP manufacturing capabilities, we have limited experience manufacturing drug substance on a commercial scale, and we will incur significant costs to develop this expertise internally.

In addition to the oligonucleotides that we manufacture internally, we continue tomay utilize CMOs to manufacture the oligonucleotides required for our preclinical studies and clinical trials. There are a limited number of manufacturers that supply oligonucleotides. There are risks inherent in pharmaceutical manufacturing that could affect our ability or the ability of our CMOs to meet our delivery time requirements or provide adequate amounts of material to meet our clinical trial demands on our projected timelines. Included in these risks are potential synthesis and purification failures and/or contamination during the manufacturing process, as well as other issues with our facility or the CMOs’ facilities and ability to comply with the applicable manufacturing requirements, which could result in unusable product and cause delays in our manufacturing timelines and ultimately delay our clinical trials, as well as result in additional expense to us. To manufacture our oligonucleotides, we rely on third parties to supply the required raw materials. We will likely need to secure alternative suppliers for these raw materials, and such alternative suppliers are limited and may not be readily available, or we may be unable to enter into agreements with them on reasonable terms and in a timely manner. For example, we source certain materials used in the manufacture of our products from China and other countries outside of the United States; the coronavirus outbreak or other similar global disruptions could makehas made access to our existing supply chain difficult and further supply chain disruptions could impact our business. Additionally, our cost of goods development is at an early stage. The actual cost to manufacture and process our product candidates could be greater than we expect and could materially and adversely affect the commercial viability of our product candidates.

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The process of manufacturing oligonucleotides is complex and we may encounter difficulties in production, particularly with respect to process development or scaling-up of our manufacturing capabilities.

The process of manufacturing oligonucleotides is complex, highly-regulated and subject to multiple risks. The complex processes associated with the manufacture of our product candidates expose us to various manufacturing challenges and risks, which may include delays in manufacturing adequate supply of our product candidates, limits on our ability to increase manufacturing capacity, and the potential for product failure and product variation that may interfere with preclinical and clinical trials, along with additional costs. We also may make changes to our manufacturing process at various points during development, and even after

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commercialization, for various reasons, such as controlling costs, achieving scale, decreasing processing time, increasing manufacturing success rate, or other reasons. Such changes carry the risk that they will not achieve their intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of current or future clinical trials, or the performance of the product, once commercialized. In some circumstances, changes in the manufacturing process may require us to perform ex vivo comparability studies and to collect additional data from patients prior to undertaking more advanced clinical trials. For instance, changes in our process during the course of clinical development may require us to show the comparability of the product used in earlier clinical trials or at earlier portions of a trial to the product used in later clinical trials or later portions of the trial. We may also make further changes to our manufacturing process before or after commercialization, and such changes may require us to show the comparability of the resulting product to the product used in the clinical trials using earlier processes. We may be required to collect additional clinical data from any modified process prior to obtaining marketing approval for the product candidate produced with such modified process. If clinical data are not ultimately comparable to that seen in the earlier trials in terms of safety or efficacy, we may be required to make further changes to our process and/or undertake additional clinical testing, either of which could significantly delay the clinical development or commercialization of the associated product candidate.

We have a robust and diverse pipeline of PN-modified, stereopure oligonucleotides, including our clinical silencing and splicing programs as well as our AIMers. Our lead clinical development programs are conducting clinical trials of our two most advanced programs indesigned to treat genetic diseases within the CNS, including ALS, FTD, HD and expect to deliver data from those trials at the end of the first quarter of 2021. Also in 2021,DMD, and we expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry to enable decision making. With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat AATD. We expect to select an AATD AIMer development candidate and initiate dosingIND-enabling toxicology studies in three new clinical trials with compounds containing our novel PN backbone chemistry modifications, including WVE-003 in HD, WVE-004 in ALS and FTD, and WVE-N531 in DMD. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating our ophthalmology programs and continue to explore additional targets in neurology and hepatic disorders. the third quarter of 2022.Although we continue to build on our experience in manufacturing oligonucleotides, we have limited experience as a company manufacturing product candidates for commercial supply. We may never be successful in manufacturing product candidates in sufficient quantities or with sufficient quality for commercial use. Our manufacturing capabilities could be affected by cost-overruns, unexpected delays, equipment failures, labor shortages, operator error, natural disasters, unavailability of qualified personnel, difficulties with logistics and shipping, problems regarding yields or stability of product, contamination or other quality control issues, power failures, and numerous other factors that could prevent us from realizing the intended benefits of our manufacturing strategy and have a material adverse effect on our business.

Furthermore, compliance with cGMP requirements and other quality issues may arise during our internal efforts to scale-up manufacturing, and with our current or any future CMOs. If contaminants are discovered in our supply of our product candidates or in our manufacturing facilities or those of our CMOs, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination. We cannot assure you that any stability failures or other issues relating to the manufacture of our product candidates will not occur in the future. Additionally, we and our CMOs may experience manufacturing difficulties due to resource constraints or as a result of labor disputes or unstable political environments. If we or our CMOs were to encounter any of these difficulties, our ability to provide our product candidate to patients in clinical trials, or to provide product for treatment of patients once approved, would be jeopardized.

We may expend our limited resources to pursue a particular product candidate or indication and fail to capitalize on product candidates or indications that may be more profitable or for which there is a greater likelihood of success.

Because we have limited financial resources, we intend to focus on developing product candidates for specific indications that we identify as most likely to succeed, in terms of both regulatory approval and commercialization. As a result, we may forego or delay pursuit of opportunities with other product candidates or for other indications that may prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable products. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

Any product candidates we develop may fail in development or be delayed to a point where they do not become commercially viable.

Before obtaining regulatory approval for the commercial distribution of any of our product candidates, we must conduct, at our own expense, extensive preclinical studies and clinical trials to demonstrate the safety and efficacy in humans of our product candidates. Preclinical and clinical testing is expensive, difficult to design and implement, can take many years to complete and is uncertain as to

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outcome, and the historical failure rate for drugs in preclinical and clinical development is high. For example, in December 2019,our first three clinical programs contained our first-generation chemistry, all of which we discontinued developmentfollowing receipt of suvodirsen for patients with DMD based on the interim analysisnegative clinical data. By contrast, all of the Phase 1 open-label extension (OLE) study.our current product candidates contain our next-generation PN backbone chemistry modifications.

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We, the FDA or comparable foreign regulatory authorities or an IRB, or similar foreign review board or ethics committee, may suspend clinical trials of a product candidate at any time for various reasons, including if we or they believe the healthy volunteer subjects or patients participating in such trials are being exposed to unacceptable health risks. Among other reasons, unacceptable side effects or other more serious adverse events of a product candidate in healthy volunteer subjects or patients in a clinical trial could result in the FDA or comparable foreign regulatory authorities suspending or terminating the trial and refusing to approve a particular product candidate for any or all indications of use.

Clinical trials also require the review, oversight and approval of IRBs or ethics committees, which review the clinical protocols for investigations that will be conducted at their institutions in order to protect the rights and welfare of human subjects. Inability to obtain or delay in obtaining IRB approval can prevent or delay the initiation and completion of clinical trials at particular sites. Furthermore, failure to provide information to the IRB as required throughout the study, such as emergent safety reports and annual updates, may result in suspension of the IRB’s approval of the trial. Our product candidates may encounter problems during clinical trials that will cause us or regulatory authorities to delay, suspend or terminate these trials, or that will delay or confound the analysis of data from these trials. If we experience any such problems, we may not have the financial resources to continue development of the product candidate that is affected or any of our other product candidates. We may also lose, or be unable to enter into, collaborative arrangements for the affected product candidate and for other product candidates we are developing. The development of one or more of our product candidates can fail at any stage of testing. We may experience numerous unforeseen events during, or as a result of, preclinical studies and clinical trials that could delay or prevent regulatory approval or our ability to commercialize our product candidates, including:

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If we do not successfully conduct clinical development, we will not be able to market and sell products derived from our product candidates and to generate product revenues. Even if we do successfully complete clinical trials, those results are not necessarily predictive of results of additional trials that may be needed before we can submit an application for regulatory approval to the FDA or foreign regulatory agencies. If the development of any of our product candidates fails or is delayed to a point where such product candidate is no longer commercially viable, our business may be materially harmed.

Results of preclinical studies and early clinical trials may not be predictive of results of future clinical trials.

The results from preclinical studies or early clinical trials of a product candidate may not predict the results that will be obtained in subsequent subjects or in subsequent clinical trials of that product candidate or any other product candidate. The design of a clinical trial can determine whether its results will support approval of a product candidate and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. In addition, preclinical and clinical data are often susceptible to varying interpretations and analyses. Product candidates that seemingly perform satisfactorily in preclinical studies may nonetheless fail to obtain regulatory approval. For example, our preclinical studies for suvodirsen yielded positive results. However, in December 2019, the interim analysis of the Phase 1 open-label extension (OLE) study of suvodirsen for patients with DMD showed no change from baseline in dystrophin expression and resulted in our discontinuation of the suvodirsen program. There is a high failure rate for drugs proceeding through clinical trials. A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in clinical development even after achieving promising results in earlier studies, and any such setbacks in our clinical development could negatively affect our business and operating results.

If we experience delays or difficulties in the enrollment of patients in clinical trials, our receipt of necessary regulatory approvals could be delayed or prevented.

Clinical trials of a new product candidate require the enrollment of a sufficient number of patients, including patients who are suffering from the disease the product candidate is intended to treat and who meet other eligibility criteria. Rates of patient enrollment are affected by many factors, including the COVID-19 global pandemic or emerging or future variants of COVID-19, the size of the patient population, the age and condition of the patients, the stage and severity of disease, the nature and requirements of the protocol;protocol, the proximity of patients to clinical sites, the availability of effective treatments for the relevant disease, and the eligibility criteria for the clinical trial. Delays or difficulties in patient enrollment or difficulties retaining trial participants, including as a result of the availability of existing or other investigational treatments, can result in increased costs, longer development times or termination of a clinical trial.

In addition, our success may depend, in part, on our ability to identify patients who qualify for our clinical trials, or are likely to benefit from any medicines that we may develop, which will require those potential patients to undergo a screening assay, which we also refer to as a companion diagnostic test, for the presence or absence of a particular genetic sequence. For example, in HD, we are conducting a clinical trials for WVE-120101 and WVE-120102, and expect to begin dosingtrial for WVE-003, in 2021. Each programwhich targets a different SNP associated with the mutant allelesallele of the HTT gene, while each SNP has a particular demographic distribution and defines a subpopulation of patients suited for allele-specific interventions.gene. Approximately 80%40% of the HD patient population carry one, two, or three of the three most common SNPs.this SNP. We have developed a novel screening assay that is intended to identify whether a patient has the particular SNP that our product candidate is targeting, and partnered with a third party for testing in future trials. If we, or any third parties that we engage to assist us are unable to successfully identify patients with the appropriate SNPsSNP that we are targeting, the percentage of patients with the SNPsSNP we are targeting is lower than expected, or we experience delays in testing, we may not realize the full commercial potential of any product candidates we develop.

If we are unable to successfully develop or obtain regulatory approval for companion diagnostic tests for our product candidates, or experience significant delays in doing so, our clinical trials may be delayed and our business could be materially harmed.

The development programs for some of our product candidates contemplate the development of companion diagnostic tests, which are assays or tests to identify an appropriate patient population. The success of certain of our product candidates will depend on several factors, including the successful development of, and ability to obtain regulatory approval for, companion diagnostic tests that will be used to screen and identify the right patients for our product candidates. Our goal is to develop and commercialize disease-modifying medicines for genetically defined diseases with a high degree of unmet medical need, and to become a fully integrated genetic medicines company. The target patient populations for several of our product candidates are relatively small, and it will be difficult to

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successfully identify the appropriate patients for whom our product candidates are being designed without reliable, accessible, relatively inexpensive, easy-to-use companion diagnostic tests.

Companion diagnostic tests are subject to regulation by the FDA and similar regulatory authorities outside the United States as medical devices and require separate regulatory authorization prior to commercialization. We are not a medical device company, and we have limited experience developing medical devices. A more detailed description of the FDA approval process for companion diagnostic tests is included under “Business – Government Regulation – In Vitro Diagnostic Tests for Biomarkers.” Given our limited

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experience in developing and commercializing companion diagnostic tests, we may seek to collaborate with third parties to assist us in the design, manufacture, regulatory authorization and commercialization of the companion diagnostic tests for some of our product candidates. In November 2019, we entered into a collaboration with Asuragen, Inc. (“Asuragen”) for the development and commercialization of companion diagnostics for our allele-selective product candidatescandidate in HD. We, Asuragen and other potential collaborators may encounter difficulties in developing and obtaining approval for the companion diagnostic tests, including issues relating to selectivity/specificity, analytical validation, reproducibility, or clinical validation. Any delay or failure by us or our collaborators to develop or obtain regulatory authorization of the companion diagnostic tests could delay or prevent approval of our product candidates. If we, Asuragen or any other third parties that we engage to assist us, are unable to successfully develop, validate, and commercialize companion diagnostic tests for our drug candidates, or experience delays in doing so, our clinical trials and our business could be materially harmed.

We may be unable to obtain regulatory approval in the United States or foreign jurisdictions and, as a result, be unable to commercialize our product candidates and our ability to generate revenue will be materially impaired.

Our product candidates are subject to extensive governmental regulations relating to, among other things, research, testing, development, manufacturing, quality, safety, efficacy, approval, recordkeeping, reporting, labeling, storage, packaging, advertising and promotion, pricing, marketing and distribution of drugs. Rigorous preclinical studies and clinical trials and an extensive regulatory approval process are required to be successfully completed in the United States and in many foreign jurisdictions before a new drug can be marketed. Satisfaction of these and other regulatory requirements is costly, time consuming, uncertain and subject to unanticipated delays. It is possible that none of the product candidates we may develop will obtain the regulatory approvals necessary for us or our collaborators to begin selling them.

The time required to obtain FDA and other approvals is unpredictable but typically takes many years following the commencement of clinical trials, depending upon the type, complexity and novelty of the product candidate. The standards that the FDA and its foreign counterparts use when regulating companies such as ours are not always applied predictably or uniformly and can change. Any analysis we perform of data from preclinical and clinical activities is subject to confirmation and interpretation by regulatory authorities, which could delay, limit or prevent regulatory approval. We may also encounter unexpected delays or increased costs due to new government regulations, for example, from future legislation or administrative action, or from changes in FDA policy during the period of product development, clinical trials and FDA regulatory review. It is impossible to predict whether legislative changes will be enacted, or whether FDA or foreign regulations, guidance or interpretations will be changed, or what the impact of such changes, if any, may be.

Any delay or failure in obtaining required approvals could adversely affect our ability to generate revenues from the particular product candidate for which we are seeking approval. Furthermore, any regulatory approval to market a product may be subject to limitations on the approved uses for which we may market the product or the labeling or other restrictions. In addition, the FDA has the authority to require a Risk Evaluation and Mitigation Strategy (“REMS”), as a condition of approval, which may impose further requirements or restrictions on the distribution or safe use of an approved drug, such as limiting prescribing rights to certain physicians or medical centers that have undergone specialized training, limiting treatment to patients as specially defined by the indication statement or who meet certain safe-use criteria, and requiring treated patients to enroll in a registry, among other requirements. These limitations and restrictions may limit the size of the market for the product and affect reimbursement by third-party payors.

We are also subject to numerous foreign regulatory requirements governing, among other things, the conduct of clinical trials, manufacturing and marketing authorization, pricing and payment. The foreign regulatory approval process varies among countries and may include all of the risks associated with FDA approval described above, as well as risks attributable to the satisfaction of local regulations in foreign jurisdictions. Approval by the FDA does not ensure approval by comparable regulatory authorities outside of the United States and vice versa.

We have beenIf we are granted orphan drug designations in the United States for someany of our product candidates, but there can be no guarantee that we will maintain orphan status for these product candidates or receive approval for any product candidate with an orphan drug designation.

In 2016 and 2017, we were granted orphan drug designation under the Orphan Drug Act by the FDA for our product candidates, WVE-120101 and WVE-120102, respectively, for the treatment of HD. Subject to receiving approval from the FDA of an NDA, products granted orphan drug status are provided with seven years of marketing exclusivity in the U.S.,United States, meaning the FDA generally will not approve applications for other product candidates for the same orphan indication that contain the same active ingredient.

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We are not guaranteed to maintain or receive orphan status for our current or future product candidates, and if our product candidates that were granted orphan status were to lose their status as an orphan drug or the marketing exclusivity provided to it in the United States, our business and results of operations could be materially adversely affected. While orphan status for any of our products, if granted or maintained, would provide market exclusivity in the United States for the time periods specified above, we would not be able to exclude other companies from manufacturing and/or selling products using the same active ingredient for the same indication

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beyond the exclusivity period applicable to our product on the basis of orphan drug status. In addition, orphan exclusivity does not block the approval of a different drug or biologic for the same rare disease or condition, nor does it block the approval of the same drug or biologic for different conditions. Even if we are the first to obtain approval of an orphan product candidate and are granted exclusivity in the United States, there are circumstances under which a later competitor product may be approved for the same indication during the period of marketing exclusivity, such as if the later product is shown to be clinically superior to our product or if we are not able to provide a sufficient quantity of the orphan drug.

Even if we obtain regulatory approvals, our marketed drugs will be subject to ongoing regulatory oversight. If we fail to comply with continuing U.S. and foreign requirements, our approvals, if obtained, could be limited or withdrawn, we could be subject to other penalties, and our business would be seriously harmed.

Following any initial regulatory approval of any drugs we may develop, we will also be subject to continuing regulatory oversight, including the review of adverse drug experiences and safety data that are reported after our drug products are made commercially available. This would include results from any post-marketing studies or surveillance to monitor the safety and efficacy of the drug product required as a condition of approval or agreed to by us. Any regulatory approvals that we receive for our product candidates may also be subject to limitations on the approved uses for which the product may be marketed. Other ongoing regulatory requirements include, among other things, submissions of safety and other post-marketing information and reports, registration and listing, as well as continued maintenance of our marketing application, compliance with cGMP requirements and quality oversight, compliance with post-marketing commitments, and compliance with good clinical practice for any clinical trials that we conduct post-approval. Failure to comply with these requirements could result in criminal or civil penalties, recalls, or product withdrawals. In addition, we are conducting our clinical trials and we intend to seek approval to market our product candidates in jurisdictions outside of the United States, and therefore will be subject to, and must comply with, regulatory requirements in those jurisdictions.

The FDA has significant post-market authority, including, for example, the authority to require labeling changes based on new safety information and to require post-market studies or clinical trials for a variety of reasons. The FDA also has the authority to require a REMS plan after approval, which may impose further requirements or restrictions on the distribution or use of an approved drug.

We, our CMOs, and the manufacturing facilities we use to make our product candidates will also be subject to ongoing assessment of product quality, compliance with cGMP, and periodic inspection by the FDA and potentially other regulatory agencies. The discovery of any new or previously unknown problems with us or our CMOs, or our or their manufacturing processes or facilities, including failure to maintain compliance with cGMP requirements, may result in the need for field alerts, product recalls, restrictions on the drug or manufacturer or facility, including withdrawal of the drug from the market. We may not have the ability or capacity to manufacture material at a broader commercial scale in the future. We and our CMOs currently manufacture a limited supply of clinical trial materials. Reliance on CMOs entails risks to which we would not be subject if we manufactured all of our material ourselves, including reliance on the CMO for regulatory compliance. Our product promotion and advertising will also be subject to regulatory requirements and continuing regulatory review.

If we or our collaborators, manufacturers or service providers fail to comply with applicable continuing regulatory requirements in the United States or foreign jurisdictions in which we may seek to market our products, we or they may be subject to, among other things, fines, warning letters, holds on clinical trials, refusal by the FDA or comparable foreign regulatory authorities to approve pending applications or supplements to approved applications, suspension or withdrawal of regulatory approval, product recalls and seizures, refusal to permit the import or export of products, operating restrictions, injunction, consent decree, civil penalties and criminal prosecution.

Even if we receive regulatory approval to market our product candidates, the market may not be receptive to our product candidates upon their commercial introduction, which will prevent us from becoming profitable.

Our product candidates are based upon new discoveries, technologies and therapeutic approaches. Key participants in pharmaceutical marketplaces, such as physicians, third-party payors and consumers, may not adopt a product intended to improve therapeutic results that is based on the technology employed by oligonucleotides. As a result, it may be more difficult for us to convince the medical community and third-party payors to accept and use our product, or to provide favorable reimbursement.

Other factors that we believe will materially affect market acceptance of our product candidates include:

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In addition, our estimates regarding the potential market size may be materially different from what we currently expect at the time we commence commercialization, which could result in significant changes in our business plan and may significantly harm our results of operations and financial condition.

The pharmaceutical industry is intensely competitive. If we are unable to compete effectively with existing drugs, new treatment methods and new technologies, we may be unable to commercialize successfully any drugs that we develop.

The pharmaceutical industry is intensely competitive and rapidly changing. Many large pharmaceutical and biotechnology companies, academic institutions, governmental agencies and other public and private research organizations are pursuing the development of novel drugs for the same diseases that we are targeting or expect to target. Many of our competitors have:

We will face intense competition from drugs that have already been approved and accepted by the medical community for the treatment of the conditions for which we may develop drugs. We also expect to face competition from new drugs that enter the market. We believe a significant number of drugs are currently under development, and may become commercially available in the future, for the treatment of conditions that our current or future product candidates are or may be designed to treat. These drugs may be more effective, safer, less expensive, or marketed and sold more effectively, than any products we develop.

Our competitors may develop or commercialize products with significant advantages over any products we are able to develop and commercialize based on many different factors, including:

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Our competitors may therefore be more successful in commercializing their products than we are, which could adversely affect our competitive position and business. Competitive products may make any products we develop obsolete or noncompetitive before we can recover the expenses of developing and commercializing our product candidates. Such competitors could also recruit our employees, which could negatively impact our level of expertise and our ability to execute on our business plan.

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If we or our collaborators, manufacturers, service providers or other third parties fail to comply with applicable healthcare laws and regulations, we or they could be subject to enforcement actions, which could affect our ability to develop, market and sell our products and may harm our reputation.

We are currently, or may in the future, be subject to federal, state, local, and comparable foreign healthcare laws and regulations relating to areas such as fraud and abuse and patients’ rights. These laws may constrain the business or financial arrangements and relationships through which we conduct our operations, including how we research, market, sell and distribute our products for which we obtain marketing approval. These laws and regulations include:

If our operations are found to be in violation of any such requirements, we may be subject to penalties, including civil or criminal penalties, criminal prosecution, monetary damages, the curtailment or restructuring of our operations, loss of eligibility to obtain approvals from the FDA, exclusion from participation in federal healthcare programs including Medicare and Medicaid, the imposition of a corporate integrity agreement with the Office of Inspector General of the Department of Health and Human Services, disgorgement, individual imprisonment, contractual damages, reputational harm, and diminished profits and future earnings, any of which could adversely affect our financial results and adversely affect our ability to operate our business. We intend to develop and implement a comprehensive corporate compliance program prior to the commercialization of our product candidates. Although effective compliance programs can mitigate the risk of investigation and prosecution for violations of these laws, these risks cannot be entirely eliminated. Any action against us for an alleged or suspected violation could cause us to incur significant legal expenses and could divert our management’s attention from the operation of our business, even if our defense is successful. In addition, achieving and sustaining compliance with applicable laws and regulations may be costly to us in terms of money, time and resources.

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If we or our collaborators, manufacturers or service providers fail to comply with applicable federal, state or foreign laws or regulations, we could be subject to enforcement actions, which could affect our ability to develop, market and sell our products successfully and could harm our reputation and lead to reduced acceptance of our products by the market. These enforcement actions include, among others:

Moreover, federal, state or foreign laws or regulations are subject to change, and while we, our collaborators, manufacturers and/or service providers currently may be compliant, that could change due to changes in interpretation, prevailing industry standards or other reasons.

Any drugs we develop may become subject to unfavorable pricing regulations, third-party reimbursement practices or healthcare reform initiatives, thereby harming our business.

Because our product candidates represent new approaches to the treatment of genetic-based diseases, we cannot be sure that coverage and reimbursement will be available for, or accurately estimate the potential revenue from, our product candidates or assure that coverage and reimbursement will be available for any product that we may develop. The regulations that govern marketing approvals, pricing and reimbursement for new drugs vary widely from country to country. Some countries require approval of the sale price of a drug before it can be marketed. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. We are monitoring these regulations as several of our programs move into later stages of development; however, many of our programs are currently in the earlier stages of development and we will not be able to assess the impact of price regulations for a number of years. As a result, we might obtain regulatory approval for a product in a particular country, but then be subject to price regulations that could delay our commercial launch of the product and negatively impact any potential revenues we may be able to generate from the sale of the product in that country and potentially in other countries due to reference pricing.

Our ability to commercialize any products successfully will also depend in part on the extent to which coverage and adequate reimbursement/payment for these products and related treatments will be available from government health administration authorities, private health insurers and other organizations. Even if we succeed in bringing one or more products to the market, these products may not be considered medically necessary and/or cost-effective, and the amount reimbursed for any products may be insufficient to allow us to sell our products on a competitive basis. At this time, we are unable to determine their cost effectiveness or the likely level or method of reimbursement for our product candidates. Increasingly, third-party payors, such as government and private insurance plans, are requiring that drug companies provide them with predetermined discounts from list prices, and are seeking to reduce the prices charged or the amounts paid for pharmaceutical products. If the price we are able to charge for any products we develop, or the payments provided for such products, is inadequate in light of our development and other costs, our return on investment could be adversely affected.

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We currently expect that any drugs we develop may need to be administered under the supervision of a physician on an outpatient basis. Under currently applicable U.S. law, certain drugs that are not usually self-administered (such as most injectable drugs) may be eligible for coverage under the Medicare Part B program if:

There may be significant delays in obtaining coverage for newly-approved drugs, and coverage may be more limited than the indications for which the drug is approved by the FDA or comparable foreign regulatory authorities. Patients who are prescribed medications for the treatment of their conditions, and their prescribing physicians, generally rely on third-party payors to pay all or part of the costs associated with their prescription drugs. Patients are unlikely to use our products unless coverage is provided and payment is adequate to cover all or a significant portion of the cost of our products. Therefore, coverage and adequate payment is critical to new product acceptance. Coverage decisions may depend upon clinical and economic standards that disfavor new drug products when more established or lower cost therapeutic alternatives are already available or subsequently become available. Moreover, eligibility for coverage does not imply that any drug will be paid for in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution. Interim payments for new drugs, if applicable, may also not be sufficient to cover our costs and may not be made permanent. Reimbursement may be based on payments allowed for lower-cost drugs that are already reimbursed, may be incorporated into existing payments for other services and may reflect budgetary constraints or imperfections in Medicare data. Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement rates. However, no uniform policy requirement for coverage and reimbursement for drug products exists among third-party payors in the United States. Therefore, coverage and reimbursement for drug products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. Our inability to promptly obtain coverage and adequate reimbursement rates from both government-funded and private payors for new drugs that we develop and for which we obtain regulatory approval could adversely affect our operating results, our ability to raise capital needed to commercialize products, and our overall financial condition.

We believe that the efforts of governments and third-party payors to contain or reduce the cost of healthcare and legislative and regulatory proposals to broaden the availability of healthcare will continue to affect the business and financial condition of pharmaceutical and biopharmaceutical companies. A number of legislative and regulatory changes in the healthcare system in the United States and other major healthcare markets have been proposed and/or adopted in recent years, and such efforts have expanded substantially in recent years. These developments have included prescription drug benefit legislation that was enacted in 2003 and took effect in January 2006, healthcare reform legislation enacted by certain states, and major healthcare reform legislation that was passed by Congress and enacted into law in the United States in 2010. These developments could, directly or indirectly, affect our ability to sell our products, if approved, at a favorable price.

In particular, in March 2010, the Patient Protection and Affordable Care Act (the “ACA”) was signed into law. This legislation changed the system of healthcare insurance and benefits and was intended to broaden access to healthcare coverage, enhance remedies against fraud and abuse, add transparency requirements for the healthcare and health insurance industries, impose taxes and fees on the healthcare industry, impose health policy reforms, and control costs. This law also contains provisions that would affect companies in the pharmaceutical industry and other healthcare related industries by imposing additional costs and changes to business practices. Since its enactment, there have been judicial and Congressional challenges to certain aspects of the ACA. The uncertainty around the future of the ACA, and in particular the impact to reimbursement levels, may lead to uncertainty or delay in the purchasing decisions of our customers, which may in turn negatively impact our product sales. We continue to evaluate the effect that the ACA has or any potential changes to the ACA could have on our business. Additional federal and state legislative and regulatory developments are likely, and we expect ongoing initiatives in the United States to increase pressure on drug pricing and reimbursement. Such reforms could have an adverse effect on anticipated revenues from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop product candidates.

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Our ability to obtain services, reimbursement or funding from the federal government may be impacted by possible reductions in federal spending.

Other legislative changes have been proposed and adopted since the ACA was enacted. For example, in August 2011, President Obama signed into law the Budget Control Act of 2011, which, among other things, created the Joint Select Committee on Deficit Reduction (Joint Select Committee) to recommend to Congress proposals in spending reductions. The failure of Congress to enact deficit reduction measures of at least $1.2 trillion for the years 2013 through 2021 triggered the legislation’s automatic reduction to several government programs. These cuts included aggregate reductions to Medicare payments to providers of up to 2% per fiscal year, which went into effect beginning on April 1, 2013, and will stay in effect through 2024 unless additional Congressional action is taken. Additionally, under the American Taxpayer Relief Act of 2012, which was enacted on January 1, 2013, the imposition of these automatic cuts was delayed until March 1, 2013. As required by law, President Obama issued a sequestration order on March 1, 2013. Certain of these automatic cuts have been implemented resulting in reductions in Medicare payments to physicians, hospitals, and other healthcare providers, among other things. The full impact on our business of these automatic cuts is uncertain.

If other federal spending is reduced, any budgetary shortfalls may also impact the ability of relevant agencies, such as the FDA or National Institutes of Health to continue to function. Amounts allocated to federal grants and contracts may be reduced or eliminated. These reductions may also impact the ability of relevant agencies to timely review and approve drug research and development, manufacturing, and marketing activities, which may delay our ability to develop, market and sell any products we may develop.

Changes in laws and regulations affecting the healthcare industry could adversely affect our business.

All aspects of our business, including research and development, manufacturing, marketing, pricing, sales, litigation, and intellectual property rights, are subject to extensive legislation and regulation. Changes in applicable U.S. federal and state laws and agency regulation, as well as foreign laws and regulations, could have a materially negative impact on our business. In the United States and

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in some other jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of our product candidates or any potential future product candidates of ours, restrict or regulate post-approval activities, or affect our ability to profitably sell any product candidates for which we obtain marketing approval. Increased scrutiny by the U.S. Congress of the FDA’s approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing testing and other requirements. Congress also must reauthorize the FDA’s user fee programs every five years and often makes changes to those programs in addition to policy or procedural changes that may be negotiated between the FDA and industry stakeholders as part of this periodic reauthorization process. The negotiation process for the next cycle of prescription drug and medical devicegeneric drug user fee programs is beginningwas completed in 20202021 as those programs must be reauthorized by Congress in mid-2022.

Among policy makers and payors in the United States and elsewhere, there is significant interest in promoting changes in health care systems with the stated goals of containing health care costs, improving quality and/or expanding access. In the United States, the pharmaceutical industry has been a focus of these efforts and has been significantly affected by major legislative initiatives. In March 2010, Congress passed the ACA, which substantially changed the way health care is financed by both the government and private insurers, and significantly impacts the United StatesU.S. pharmaceutical industry. As another example, the 2021 Consolidated Appropriations Act signed into law on December 27, 2020 incorporated extensive health care provisions and amendments to existing laws, including a requirement that all manufacturers of drug products covered under Medicare Part B report the product’s average sales price, or ASP, to DHHS beginning on January 1, 2022, subject to enforcement via civil money penalties.  

There remain judicial and Congressional challenges to certain aspects of the ACA, and as a result certain sections of the ACA have not been fully implemented or effectively repealed. In particular,However, following several years of litigation in December of 2018, a Texasthe federal courts, in June 2021, the U.S. DistrictSupreme Court Judge ruled thatupheld the ACA is unconstitutional in its entirety becausewhen it dismissed a legal challenge to the individual mandate was repealed by Congress as part of the Tax Cutslaw’s constitutionality. Further legislative and Jobs Act, effective January 1, 2019. In December 2019, the Fifth Circuit Court of Appeals upheld the district court’s ruling that the individual mandate inregulatory changes under the ACA was unconstitutional but remandedremain possible, although the casenew federal administration under President Biden has signaled that it plans to the district court to determine whether other reforms enacted as part ofbuild on the ACA but not specifically related toand expand the individual mandate ornumber of people who are eligible for health insurance could be severed from the rest of the ACA so as not to have the law declared invalid in its entirety. On March 2, 2020, the United States Supreme Court granted the petitions for writs of certiorari to review this case and allocated one hour for oral arguments, which occurred on November 10, 2020. A decision from the Supreme Court is expected to be issued in spring 2021.subsidies under it. It is unclearunknown what form any such changes or any law would take, and how this litigation and other efforts to repeal and replace the ACA willor whether it may affect the implementation of that law, the pharmaceutical industry more generally, andas a whole or our business.   Additionally,business in the 2020 federal spending package permanently eliminated, effective January 1, 2020, the ACA-mandated “Cadillac” tax on high-cost employer-sponsored health coverage and medical device tax and, effective January 1, 2021, also eliminates the health insurer tax. Further, the Bipartisan Budget Act of 2018, among other things, amendedfuture. We expect that changes or additions to the ACA, effective January 1, 2019,the Medicare and Medicaid programs, such as changes allowing the federal government to closedirectly negotiate drug prices, and changes stemming from other healthcare reform measures, especially with regard to healthcare access, financing or other legislation in individual states, could have a material adverse effect on the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole.” In addition, CMS published a final rule that would give states greater flexibility, effective January 1, 2020, in setting benchmarks for insurershealthcare industry in the individual and small group

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marketplaces, which may have the effect of relaxing the essential health benefits required under the ACA for plans sold through such marketplaces. We continue to evaluate the potential impact of the ACA and its possible repeal or replacement on our business.United States.

The uncertainty around the future of the ACA, and in particular the impact to reimbursement levels, may lead to uncertainty or delay in the purchasing decisions of our customers, which may in turn negatively impact our product sales. If there are not adequate reimbursement levels, our business and results of operations could be adversely affected.

In addition, other legislative changes have been proposed and adopted since the ACA was enacted. These changes include aggregate reductions to Medicare payments to providers of up to 2% per fiscal year pursuant to the Budget Control Act of 2011, which began in 2013 and will remain in effect through 2030 unless additional Congressional action is taken.  However, the Medicare sequester reductions under the Budget Control Act of 2011 was suspended from May 1, 2020 through December 31, 2020 due to the COVID-19 pandemic, pursuant to provisions of the Coronavirus Aid, Relief, and Economic Security Act or (“the CARES Act,“CARES Act”), which also extended the sequester by one year, through 2030, in order to offset the added expense of the 2020 cancellation. The 2021 Consolidated Appropriations Actsuspension was subsequently signed into law on December 27, 2020 and extends the CARES Act suspension period toextended through March 31, 2021.2022, with a reduction of the suspension to 1% sequester through June 30, 2022.

In addition, the Drug Supply Chain Security Act enacted in 2013 imposed obligations on manufacturers of pharmaceutical products related to product tracking and tracing. More recently,tracing, and in February 2022, FDA released proposed regulations to amend the national standards for licensing of wholesale drug distributors by the states; establish new minimum standards for state licensing third-party logistics providers; and create a federal system for licensure for use in the absence of a State program, each of which is mandated by the DSCSA. As another example, on December 20, 2019, President Trump signed the Further Consolidated Appropriations Act for 2020 into law (P.L. 116-94) that includes a piece of bipartisan legislation called the CREATES Act. The CREATES Act aims to address the concern articulated by both the FDA and others in the industry that some brand manufacturers have improperly restricted the distribution of their products, including by invoking the existence of a REMS for certain products, to deny generic and biosimilar product developers access to samples of brand products. The CREATES Act establishes a private cause of action that permits a generic or biosimilar product developer to sue the brand manufacturer to compel it to furnish the necessary samples on “commercially reasonable, market-based terms.” Whether and how generic and biosimilar product developments will use this new pathway, as well as the likely outcome of any legal challenges to provisions of the CREATES Act, remain highly uncertain and its potential effects on our future commercial products are unknown. Other legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for pharmaceutical products. We are unsure whether additional legislative changes will be enacted, or whether the current regulations, guidance or interpretations will be changed, or whether such changes will have any impact on our business.

Additionally, there has been heightened governmental scrutiny in the United States of pharmaceutical pricing practices considering the rising cost of prescription drugs and biologics. Such scrutiny has resulted in several recent congressional inquiries and proposed and

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enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for products. For example, state legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. In December 2020, the U.S. Supreme Court held unanimously that federal law does not preempt the states’ ability to regulate pharmaceutical benefit managers (PBMs) and other members of the health care and pharmaceutical supply chain, an important decision that may lead to further and more aggressive efforts by states in this area.

At the federal level, DHHS has solicited feedback on various measures intended to lower drug prices and reduce the out of pocket costs of drugs and has implemented others under its existing authority. For example, in May 2019, CMS issued a final rule to allow Medicare Advantage plans the option to use step therapy for Part B drugs beginning January 1, 2020. This final rule codified CMS’s policy change that was effective January 1, 2019. In addition, in September 2020, the FDA finalized a rulemaking to establish a system whereby state governmental entities could lawfully import and distribute prescription drugs sourced from Canada. Those new regulations became effective on November 30, 2020, although the impact of such future programs is uncertain in part because lawsuits have been filed challenging the government’s authority to promulgate them. The final regulations may also be vulnerable to being overturned by a joint resolution of disapproval from Congress under the procedures set forth in the Congressional Review Act, which could be applied to regulatory actions taken by the Trump administration on or after August 21, 2020 (i.e., in the last 60 days of legislative session of the 116th Congress). Congress and the executive branch have each indicated that it will continue to seek new legislative and/or administrative measures to control drug costs. For example, in July 2020, President Trump announced four executive orders related to prescription drug pricing that attempted to implement several of his Administration’s proposals, including a policy that would tie Medicare Part B drug prices to international drug prices; one that directed DHHS to finalize the Canadian drug importation proposed rule previously issued by DHHS (which has since been finalized, as noted above) and made other changes allowing for personal importation of drugs from Canada; one that directed DHHS to finalize the rulemaking process on modifying the anti-kickback law safe harbors for plans, pharmacies, and pharmaceutical benefit managers after DHHS confirms that the action is not projected to increase federal spending, Medicare beneficiary premiums, or patients’ total out-of-pocket costs (which DHHS finalized

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in November 2020, also making those rules subject to potentially being overturned under the Congressional Review Act); and one that reduces costs of insulin and epinephrine auto-injectors to patients of federally qualified health centers. President Trump also issued another executive order on September 13, 2020 that directed DHHS to undertake rulemaking in order to test an international reference pricing model for prescription drug products, which was also implemented by DHHS and then challenged in federal court by industry groups in December 2020. The probability of success of these newly announced policies and their impact on the U.S. prescription drug marketplace is unknown. There are likely to be continued political and legal challenges associated with implementing these reforms as they are currently envisioned, and the January 20, 2021 transition to a new Democrat-led presidential administration created further uncertainty. Following his inauguration, President Biden took immediate steps to order a regulatory freeze on all pending substantive executive actions in order to permit incoming department and agency heads to review whether questions of fact, policy, and law may be implicated and to determine how to proceed.  The implementation of cost containment measures or other health care reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our products. Current and future health care legislation could have a significant impact on our business. There is uncertainty with respect to the impact these changes, if any, may have, and any changes likely will take time to unfold. In addition, it is possible that additional governmental action is taken to address the COVID-19 pandemic. For example, on April 18, 2020, CMS announced that qualified health plan issuers under the ACA may suspend activities related to the collection and reporting of quality data that would have otherwise been reported between May and June 2020 given the challenges health care providers are facing responding to the COVID-19 virus. Any additional federal or state health care reform measures could limit the amounts that third-party payers will pay for future health care products and services, and, in turn, could significantly reduce the projected value of certain development projects and reduce our profitability.

Risks associated with our operations outside of the United States and developments in international trade by the U.S. and foreign governments could adversely affect our business.

We have operations and conduct business outside the United States, and we plan to continue to expand these operations. Therefore, we are subject to risks related to operating in foreign countries, which include unfamiliar foreign laws or regulatory requirements or unexpected changes to those laws or requirements; other laws and regulatory requirements to which our business activities abroad are subject, such as the Foreign Corrupt Practices Act and the U.K. Bribery Act; changes in the political or economic condition of a specific country or region; fluctuations in the value of foreign currency versus the U.S. dollar; our ability to deploy overseas funds in an efficient manner; tariffs, trade protection measures, import or export licensing requirements, trade embargoes, and sanctions (including those administered by the Office of Foreign Assets Control of the U.S. Department of the Treasury), and other trade barriers; global instability from an outbreak of pandemic or contagious disease, including the COVID-19 global pandemic and variants thereof; difficulties in attracting and retaining qualified personnel; and cultural differences in the conduct of business. For example, given developments related to international trade over the past few years, unexpected changes in tariffs could adversely affect our cost of goods sold and/or the foreign sales of our product candidates. Further complicating potential uncertainties caused by conducting business outside the United States are recent political movements that are changing decades-old institutions, including, for example, in 2016, the United Kingdom held a referendum in which voters approved an exit from the European Union, commonly referred to as “Brexit.” On March 29, 2017, the United Kingdom formally notified the European Union of its intention to withdraw pursuant to Article 50 of the Lisbon Treaty. The withdrawal of the United Kingdom from the European Union took effect on January 31, 2020, the effective date of the withdrawal agreement, with a transition period that ended on December 31, 2020. Since a significant proportion of the regulatory framework in the United Kingdom was, prior to Brexit, derived from European Union directives and regulations, Brexit and the new Trade and Cooperation Agreement between the European Union and the United Kingdom that took provisional effect on January 1, 2021 could materially impact the regulatory regime with respect to the approval of any product candidates in the United Kingdom. Changes impacting our ability to conduct business in the United Kingdom or other European Union countries, or changes to the regulatory regime applicable to our operations in those countries (such as with respect to the approval of our product candidates), may materially and adversely impact our business, prospects, operating results, and financial condition. Given the lack of comparable precedent, it is unclear what financial, trade, regulatory and legal implications the withdrawal of the United Kingdom from the European Union would have and how such withdrawal would affect us. Any of these effects of Brexit, among others, could adversely affect our business, financial condition and operating results.

We or third parties upon whom we depend may be adversely affected by natural disasters and/or health epidemics (including the COVID-19 pandemic and variants thereof), and our business, financial condition and results of operations could be adversely affected.

Natural disasters could severely disrupt our operations and have a material adverse effect on our business operations. If a natural disaster, health epidemic, or other event beyond our control occurred that prevented us from using all or a significant portion of our office, manufacturing and/or lab spaces, that damaged critical infrastructure, such as the manufacturing facilities of our third-party contract manufacturers, or that otherwise disrupted operations, it may be difficult for us to continue our business for a substantial period of time. Any outbreak of contagious diseases, or other adverse public health developments, could have a material and adverse effect on our business operations. For example,Clinical site initiation and patient enrollment in our clinical trials have been delayed due to prioritization of hospital resources in favor of COVID-19 was declared a pandemic by the World Health Organization on March 11, 2020patients and is continuing to evolve.difficulties in recruiting clinical site investigators and clinical site staff. The COVID-19 global pandemic, including emerging or future variants of COVID-19, and its

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impact on our business is

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highly uncertain and subject to change. We do not yet know the full extent of potential delays or long-term impacts on our business, our preclinical studies and clinical trials, healthcare systems or the global economy. In addition, certain of our research and development efforts are conducted globally. A health epidemic or other outbreak could materially and adversely affect our business, financial condition and results of operations.

The disaster recovery and business continuity plans we have in place may prove inadequate in the event of a serious disaster or similar event. We may incur substantial expenses as a result of the limited nature of our disaster recovery and business continuity plans, which could have a material adverse effect on our business.

There is a substantial risk of product liability claims in our business. If we are unable to obtain or maintain sufficient insurance, a product liability claim against us could adversely affect our business.

Our business exposes us to significant potential product liability risks that are inherent in the development, testing, manufacturing and marketing of human therapeutic products. Product liability claims could delay or prevent completion of our clinical development programs. In addition, if any of our collaboration partners face product liability claims, our programs could also be affected and our business could be harmed. If we succeed in marketing products, such claims could result in an FDA investigation of the safety and effectiveness of our products, our manufacturing processes and facilities or our marketing programs, and potentially a recall of our products or more serious enforcement action, limitations on the approved indications for which they may be used, or suspension or withdrawal of approvals. Regardless of the merits or eventual outcome, liability claims may also result in decreased demand for our products, injury to our reputation, costs to defend the related litigation, a diversion of management’s time and our resources, substantial monetary awards to trial participants or patients and a decline in our share price. Any insurance we obtain may not provide sufficient coverage against potential liabilities. Furthermore, clinical trial and product liability insurance is becoming increasingly expensive. As a result, we may be unable to obtain or maintain sufficient insurance at a reasonable cost to protect us against losses caused by product liability claims that could adversely affect our business.

If we do not comply with laws regulating the protection of the environment and health and human safety, our business could be adversely affected.

Our research, development and manufacturing processes involve the use of hazardous materials, chemicals and various radioactive compounds. We maintain quantities of various flammable and toxic chemicals in our facilities that are required for our research, development and manufacturing activities. We are subject to federal, state and local laws and regulations governing the use, manufacture, storage, handling and disposal of these hazardous materials. We believe our procedures for storing, handling and disposing of these materials comply with the relevant guidelines and laws of the jurisdictions in which our facilities are located. Although we believe that our safety procedures for handling and disposing of these materials comply with the standards mandated by applicable regulations, the risk of accidental contamination or injury from these materials cannot be eliminated. If an accident occurs, we could be held liable for resulting damages, which could be substantial. We are also subject to numerous environmental, health and workplace safety laws and regulations, including those governing laboratory procedures, exposure to blood-borne pathogens and the handling of biohazardous materials. Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of these materials, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of biological, hazardous or radioactive materials. Additional federal, state and local laws and regulations affecting our operations may be adopted in the future. We may incur substantial costs to comply with, and substantial fines or penalties if we violate any of, these laws or regulations.

Risks Related to Our Dependence on Third Parties

We depend on collaborations with third parties for the development and commercialization of certain of our product candidates.

We depend on third-party collaborators for the co-development and co-commercialization of certain of our product candidates and we face significant competition to the extent we elect to collaborate with others. Our potential future collaborators include large and mid-size pharmaceutical companies, regional and national pharmaceutical companies and biotechnology companies. In addition, there have been a significant number of recent business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators. In April 2018, we commenced a collaboration with Takeda to discover, develop and commercialize oligonucleotides for disorders of the CNS. The collaboration provides Takeda with the option to globally co-develop and commercialize programs targeting HD, ALS, FTD, and SCA3, which we will have the right to co-commercialize in the United States. In addition, Takeda will have the right to exclusively license multiple preclinical programs for CNS disorders, including Alzheimer’s disease (“AD”) and Parkinson’s disease (“PD”). Collaborations are complex and time-consuming to negotiate and document. In October 2021, we and Takeda amended the collaboration, which discontinued the Category 2 component of the collaboration and Takeda paid us an additional $22.5 million for collaboration-related research and preclinical expenses. We may not be able to negotiate collaborations on a timely basis, on acceptable terms, or at all. We may also be restricted under existing license or collaboration agreements from entering into agreements on certain terms with other potential collaborators. If we are unable to enter into collaborations with respect to a product candidate, we

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may have to curtail the development of such product

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candidate, reduce or delay its development program or one or more of our other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, or increase our expenditures and undertake development or commercialization activities at our own expense. If we elect to increase our expenditures to fund development or commercialization activities on our own, we may need to obtain additional capital, which may not be available to us on acceptable terms or at all. If we do not have sufficient funds, we may not be able to further develop our product candidates or bring them to market and generate product revenue.

Depending on the type of collaborations we enter into, we may have limited control over the amount and timing of resources that our collaborators dedicate to the development or commercialization of our product candidates. Our ability to generate revenues from these arrangements will depend on our collaborators’ abilities and efforts to successfully perform the functions assigned to them in these arrangements.

Collaborations involving our product candidates may pose the following risks to us:

Collaboration agreements may not lead to development or commercialization of product candidates in the most efficient manner, or at all. Further, if a present or future collaborator of ours were to be involved in a business combination, the continued pursuit and emphasis on our product development or commercialization program could be delayed, diminished or terminated.

We may not be able to execute our business strategy optimally if we are unable to maintain our existing collaborations or enter into new collaborations with partners that can provide sales, marketing and distribution capabilities and funds for the development and commercialization of our product candidates.

We do not currently have any sales and marketing or distribution capabilities. Accordingly, we have entered into a collaboration with Takeda in CNS, which we believe can assist us in building these capabilities. We may also enter into additional alliances in the future. We have selectively chosen to enter into a collaboration in the field of CNS with Takeda because we believe this is the optimal way for us to leverage our resources and create significant value for ourselves and our shareholders, as we advance oligonucleotide candidates for genetically defined diseases.

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Depending on the collaborations that we enter into, we may expect our collaborators to provide assistance with development, regulatory affairs, marketing, sales and distribution, among other areas. Our future revenues may depend heavily on the success of the efforts of these third parties. For example, under our collaboration with Takeda, if Takeda exercises its option with respect to any of our programs in HD, ALS, FTD or SCA3, we will rely on Takeda for commercialization of such optioned programs outside of the United States. In addition, Takeda will be solely responsible for the potential commercialization of additional to-be-identified preclinical CNS programs globally based on targets that Takeda identifies.

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We may not be successful in our collaborations due to various factors, including our ability to successfully demonstrate proof of mechanism in humans, our ability to demonstrate the safety and efficacy of our specific product candidates, our ability to manufacture or have third parties manufacture our product candidates, the strength of our intellectual property and/or concerns about potential challenges to or limitations of our intellectual property. To the extent we have entered into, or enter into new, collaborations, we may not be able to maintain them if, for example, development or approval of a product candidate is delayed, challenges are raised as to the validity or scope of our intellectual property or sales of an approved drug are lower than we or our collaboration partner expected.

For certain product candidates that we may develop, we have formed collaborations to fund all or part of the costs of drug development and commercialization, such as our collaboration with Takeda. We may not, however, be able to enter into additional collaborations for certain other programs, and the terms of any collaboration agreement we do secure may not be favorable to us. If we are not successful in our efforts to enter into future collaboration arrangements with respect to one or more of our product candidates, we may not have sufficient funds to develop that or any other product candidate internally, or to bring any product candidates to market. If we do not have sufficient funds to develop and bring our product candidates to market, we will not be able to generate sales revenues from these product candidates, and this will substantially harm our business.

We rely, and expect to continue to rely, on third parties to conduct some aspects of our compound formulation, research, preclinical studies and clinical trials, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such formulation, research or testing.

We do not independently conduct all aspects of our drug discovery activities, compound formulation research, preclinical studies, or clinical trials of product candidates. We currently rely, and expect to continue to rely, on third parties to conduct some aspects of our research and development, preclinical and clinical studies. Any of these third parties may terminate their engagements with us at any time. If we need to enter into alternative arrangements, it would delay our product development activities. Our reliance on these third parties for research and development activities will reduce our control over these activities but will not relieve us of our responsibilities. For example, for product candidates that we develop and commercialize on our own, we will remain responsible for ensuring that each of our studies that support our clinical trial applications and our clinical trials are conducted in accordance with the study plan and protocols for the trial. If these third parties do not successfully carry out their contractual duties, meet expected deadlines or conduct our studies in accordance with regulatory requirements or our stated study plans and protocols, we will not be able to complete, or may be delayed in completing, the necessary preclinical studies to enable us or our strategic alliance partners to select viable product candidates for clinical trial application submissions and will not be able to, or may be delayed in our efforts to, successfully develop and commercialize such product candidates.

We rely on third parties to design, conduct, supervise and monitor our preclinical studies and clinical trials, and if those third parties perform in an unsatisfactory manner, it may harm our business.

We rely on third party clinical investigators, contract research organizations (“CROs”), clinical data management organizations and consultants to design, conduct, supervise and monitor preclinical studies and clinical trials of our product candidates. Because we rely on third parties and do not have the ability to conduct preclinical studies or clinical trials independently, we have less control over the timing, quality and other aspects of preclinical studies and clinical trials than we would if we conducted them on our own.own, including our inability to control whether sufficient resources are applied to our programs.  If any of our CROs are acquired or consolidated, these concerns are likely to be exacerbated and our preclinical studies or clinical trials may be further impacted due to potential integration, streamlining, staffing and logistical changes. These investigators, CROs and consultants are not our employees and we have limited control over the amount of time and resources that they dedicate to our programs. These third parties may have contractual relationships with other entities, some of which may be our competitors, which may draw time and resources from our programs. Further, these third parties may not be diligent, careful or timely in conducting our preclinical studies or clinical trials, resulting in the preclinical studies or clinical trials being delayed or unsuccessful.

If we cannot contract with acceptable third parties on commercially reasonable terms, or at all, or if these third parties do not carry out their contractual duties, satisfy legal and regulatory requirements for the conduct of preclinical studies or clinical trials or meet expected deadlines, our preclinical and clinical development programs could be delayed and otherwise adversely affected. In all events, we are responsible for ensuring that each of our preclinical studies and clinical trials is conducted in accordance with the general investigational plan and protocols for the trial. The FDA and other health authorities require clinical trials to be conducted in accordance with good clinical practices, including conducting, recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of clinical trial participants are protected. If we or our CROs fail to comply with these requirements, the data generated in our clinical trials may be deemed unreliable or

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uninterpretable and the FDA and other health authorities may require us to perform additional clinical trials. Our reliance on third parties that we do not control does not relieve us of these responsibilities and requirements. Any such event could adversely affect our business, financial condition, results of operations and prospects.

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We rely on third parties in the supply and manufacture our product candidates for our research, preclinical and clinical activities, and may do the same for commercial supplies of our product candidates.

While we have built our own internal manufacturing capabilities, we have not yet manufactured our product candidates on a commercial scale, and may not be able to do so for any of our product candidates. In addition, we currently rely on third parties in the supply and manufacture the materials for our research, preclinical and clinical activities and may continue to do so for the foreseeable future. We may do the same for the commercial supply of our drug product. We use third parties to perform additional steps in the manufacturing process, such as the filling, finishing and labeling of vials and storage of our product candidates and we expect to do so for the foreseeable future. There can be no assurance that our supply of research and development, preclinical and clinical development drug candidates and other materials will not be limited, interrupted or restricted or will be of satisfactory quality or continue to be available at acceptable prices. Replacement of any of the third parties we may engage could require significant effort and expertise because there may be a limited number of qualified replacements. In addition, raw materials, reagents, and components used in the manufacturing process, particularly those for which we have no other source or supplier, may not be available, may not be suitable or acceptable for use due to material or component defects, or may introduce variability into the supply of our product candidates. Furthermore, with the increase of companies developing nucleic acid therapeutics, there may be increased competition for the supply of the raw materials that are necessary to make our oligonucleotides, which could severely impact the manufacturing of our product candidates.

We may be unable to identify manufacturers on acceptable terms or at all because the number of potential manufacturers is limited and they must be acceptable to the FDA or approved by foreign regulatory authorities Suppliers and manufacturers, including us, must meet applicable manufacturing requirements, including compliance with cGMP regulations, and undergo rigorous facility and process validation tests required by regulatory authorities in order to comply with regulatory standards. In the event that any of our suppliers or manufacturers fail to comply with such requirements or to perform itstheir obligations to us in relation to quality, timing or otherwise, some of which may be out of their or our control, or if our supply of components or other materials becomes limited or interrupted for other reasons, we may be forced to increase the manufacturing of the materials ourselves, for which we currently have limited capabilities and resources, or enter into an agreement with another third party, which we may not be able to do on reasonable terms, if at all. Any interruption of the development or operation of the manufacturing of our product candidates, such as order delays for equipment or materials, equipment malfunction, quality control and quality assurance issues, regulatory delays and possible negative effects of such delays on supply chains and expected timelines for product availability, production yield issues, shortages of qualified personnel, discontinuation of a facility or business or failure or damage to a facility resulting from natural disasters, could result in the cancellation of shipments, loss of product in the manufacturing process or a shortfall in available product candidates or materials. In some cases, the technical skills or technology required to manufacture our product candidates may be unique or proprietary to the original manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills or technology to another third party and a feasible alternative may not exist. These factors would increase our reliance on such manufacturer or require us to obtain a license from such manufacturer in order to have another third party manufacture our product candidates. If we are required to change manufacturers for any reason, we will be required to verify that the new manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations and guidelines. The delays associated with the verification of a new manufacturer could negatively affect our ability to develop product candidates in a timely manner or within budget.

We may rely on third party manufacturers if we receive regulatory approval for any product candidate. To the extent that we have existing, or enter into future, manufacturing arrangements with third parties, we will depend on these third parties to perform their obligations in a timely manner consistent with contractual and regulatory requirements, including those related to quality control and assurance. We may also be required to enter into long-term manufacturing agreements that contain exclusivity provisions and/or substantial termination penalties which could have a material adverse effect on our business prior to or after commercialization of any of our product candidates. If we are unable to obtain or maintain third-party manufacturing for product candidates, or to do so on commercially reasonable terms, we may not be able to develop and commercialize our product candidates successfully. Failure to execute on our manufacturing requirements, either by us or by one of our third-party vendors, could adversely affect our business in a number of ways, including:

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If any of our product candidates are approved for marketing and commercialization and we are unable to develop sales, marketing and distribution capabilities on our own, or enter into agreements with third parties to perform these functions on acceptable terms, we will be unable to commercialize successfully any such future products.

We currently have no sales, marketing or distribution capabilities. In addition, while our collaboration with Takeda will provide us with know-how and experience related to commercialization, we have limited experience of our own. If any of our product candidates is approved, we will need to develop internal sales, marketing and distribution capabilities to commercialize such products, which would be expensive and time-consuming, or rely on or enter into additional collaborations with third parties to perform these services. If we decide to market our products directly, we will need to commit significant financial and managerial resources to develop a marketing and sales force with technical expertise and supporting distribution, administration and compliance capabilities. If we rely on third parties with such capabilities to market our products or decide to co-promote products with collaborators, we will need to establish and maintain marketing and distribution arrangements with third parties, and there can be no assurance that we will be able to enter into such arrangements on acceptable terms or at all. In entering into third-party marketing or distribution arrangements, any revenue we may receive will depend upon the efforts of the third parties and there can be no assurance that such third parties will establish adequate sales and distribution capabilities or be successful in gaining market acceptance of any approved product. If we are not successful in commercializing any product approved in the future, either on our own or through third parties, our business, financial condition, results of operations and prospects would be adversely affected.

Risks Related to Managing Our Operations

If we are unable to attract and retain qualified key management and scientists, staff, consultants and advisors, our ability to implement our business plan may be adversely affected.

We are highly dependent upon our senior management and our scientific, clinical and medical staff and advisors. The loss of the service of any of the members of our senior management or other key employees could delay our research and development programs and materially harm our business, financial condition, results of operations and prospects. In addition, we expect that we will continue to have an increased need to recruit and hire qualified personnel as we advance our programs and expand operations. Failure to successfully recruit and retain personnel could impact our anticipated development plans and timelines. For example, in 2019, as a result of the stock price decline and our workforce reduction following the announcement of our decision to discontinue our development of suvodirsen in DMD, and more recently, in light of the COVID-19 global pandemic, we may facehave faced challenges in retaining and attracting employees to support our research and development efforts, and our failure to do so could have an adverse effect on our ability to execute on our business plan. We are dependent on the continued service of our technical personnel because of the highly technical and novel nature of our product candidates, platform and technologies and the specialized nature of the regulatory approval process. Replacing such personnel may be difficult and may take an extended period of time because of the limited number of individuals in our industry with the breadth of skills and experience required to successfully execute our business strategy.strategy, and we cannot assure you that we will be able to identify or employ qualified personnel for any such position on acceptable terms, if at all. Many of the biotechnology and pharmaceutical companies with whom we compete for qualified personnel have greater financial and other resources, different risk profiles and longer histories in the industry than we do. Because our management team and key employees are not obligated to provide us with continued service, they could terminate their employment with us at any time without penalty. We do not maintain key person life insurance policies on any of our management team members or key employees. Our future success will depend in large part on our continued ability to attract and retain highly qualified scientific, technical and management personnel, as well as personnel with expertise in preclinical and clinical testing, manufacturing, governmental regulation and commercialization. In order to do so, we may need to pay higher compensation or fees to our employees or consultants than we currently expect, and such higher compensation payments may have a negative effect on our operating results. We face increased competition for personnel from other companies, universities, public and private research institutions, government entities and other organizations. If we are unable to attract and retain qualified personnel, the rate and success at which we may be able to discover and develop our product candidates and implement our business plan will be limited.

As we continue our preclinical studies and clinical trials and advance to further clinical development, we may experience difficulties in managing our growth and expanding our operations.

Although we have assembled a team of employees with experience developing medicines and obtaining regulatory approval to market those medicines, we have limited experience as a company in drug development. WeOur lead clinical development programs are conducting clinical trials of our two most advanced programs indesigned to treat genetic diseases within the CNS, including ALS, FTD, HD and expect to deliver data from those trials at the end of the first quarter of 2021. Also in 2021,DMD, and we expect to share clinical data in 2022 to provide insight into the clinical effects of PN chemistry to enable decision making. With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat AATD. We expect to select an AATD AIMer development candidate and initiate dosingIND-enabling toxicology studies in three new clinical trials with compounds containing our novel PN backbone chemistry modifications, including WVE-003 in HD, WVE-004 in ALS and FTD, and WVE-N531 in DMD. Beyond neurology, we are advancing our first ADAR editing program in alpha-1 antitrypsin disorders. We are also evaluating our ophthalmology programs and continue to explore additional targets in neurology and hepatic disorders. the third quarter of 2022. As we advance product candidates through preclinical studies and clinical trials, we will need to expand our development, regulatory and manufacturing capabilities or contract with other organizations to provide these capabilities for us. In addition, we must manage our relationships with collaborators or partners, suppliers and other organizations, including our collaboration with Takeda. Our ability to manage our operations and future growth will require us to continue to improve our operational, financial and management controls, reporting systems and procedures. We may not be able to implement improvements to our management information and control systems in an

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efficient or timely manner and may discover deficiencies in existing systems and controls. In addition, our future growth may require significant capital expenditures and may divert financial resources from other projects, such as the development of our product candidates. If we are unable to effectively manage our future growth, our expenses may increase and our ability to generate revenue could be reduced.

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Our employees, consultants and collaborators may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.

We are exposed to the risk of fraud and other misconduct by our employees, consultants and collaborators. Such misconduct could include intentional failures to comply with FDA and other foreign agency regulations, provide accurate information to the FDA, comply with manufacturing standards required by the FDA or that we may establish, comply with federal and state healthcare fraud and abuse laws and regulations, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Such misconduct could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. It is not always possible to identify and deter such misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant fines or other sanctions.

Security breaches, cyber security threats, loss of data and other disruptions could compromise sensitive information related to our business, prevent us from accessing critical information or expose us to liability, which could adversely affect our business and our reputation.

In the ordinary course of our business, we, our CROs and other third parties on which we rely collect and store sensitive data, including legally protected patient health information, personally identifiable information about our employees, intellectual property, vendor information, and proprietary business information. We manage and maintain our applications and data utilizing on-site systems. These applications and data encompass a wide variety of business-critical information, including research and development information and business and financial information.

The secure processing, storage, maintenance and transmission of this critical information by us, or our CROs and other third parties, is vital to our operations and business strategy. Although we are proactive in our approach and take measures to protect sensitive information from unauthorized access or disclosure, our information technology and infrastructure, or that of our CROs or other third parties, may be vulnerable to attacks by hackers, viruses, breaches, interruptions due to employee error, malfeasance or other disruptions, lapses in compliance with privacy and security mandates, or damage from natural disasters, terrorism, war and telecommunication and electrical failures. For example, the COVID-19 pandemic has led to an increase in those working remotely, including our employees and third parties we do business with, which increases our cyber security risk, has created data accessibility concerns, and has made us more susceptible to communication disruptions. In addition, cyberattacks, malicious internet-based activity and fraud are prevalent and continue to increase in frequency. Any such event, including a cyberattack, could compromise our networks, or that of our CROs or other third parties, and the information stored there could be accessed by unauthorized parties, publicly disclosed, lost or stolen. Furthermore, any such event could result in information theft, data corruption, operational disruption, damage to our reputation, or financial loss, and could subject us to liability or negatively impact our business operations.

We have measures in place that are designed to detect and respond to such security incidents and breaches of privacy and security mandates. Any such access, disclosure or other loss of information could result in legal claims or proceedings, liability under laws that protect the privacy of personal information, such as the HIPAA, government enforcement actions and regulatory penalties. Unauthorized access, loss or dissemination could also disrupt our operations, including our ability to conduct research and development activities, process and prepare company financial information, manage various general and administrative aspects of our business and damage our reputation, any of which could adversely affect our business. For example, the loss of clinical trial data from completed or ongoing or planned clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. In addition, there can be no assurance that we, or our CROs and other third parties, will promptly detect any such disruption or security breach, if at all. To the extent that any disruption or security breach were to result in a loss of or damage to our data or applications, or inappropriate disclosure of confidential or proprietary information, we could incur liability and the further development of our product candidates could be delayed.

Numerous federal, state and international laws address privacy, data protection and the collection, storing, sharing, use, disclosure and protection of personally identifiable information and other user data. Numerous states already have, and are looking to expand, data protection legislation. For example, in 2018, California enacted the California Consumer Privacy Act (“CCPA”), which became

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effective on January 1, 2020. The CCPA gives California residents expanded privacy rights and protections, and provides civil penalties for violations and a private right of action for data breaches. Outside the United States, personally identifiable information and other user data is increasingly subject to legislation and regulations in numerous jurisdictions around the world, the intent of which is to protect the privacy of information that is collected, processed and transmitted in or from the governing jurisdiction. Foreign data protection, privacy, information security, user protection and other laws and regulations are often more restrictive than those in the United States. In particular, the EU and its member states traditionally have taken broader views as to types of data that are subject to privacy and data protection laws and regulations, and have imposed greater legal obligations on companies in this regard. For example, in April 2016, European legislative bodies adopted the General Data Protection Regulation (“GDPR”), which became effective May 25, 2018. The GDPR applies to any company established in the EU as well as to those outside the EU if they collect and use personal data of EU residents. The GDPR enhances data protection obligations for processors and controllers of personal data, including, for example, expanded disclosures about how personal information is to be used, limitations on retention of

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information, mandatory data breach notification requirements and onerous new obligations on services providers. Non-compliance with the GDPR may result in monetary penalties of up to €20 million or 4% of annual worldwide revenue, whichever is higher. While we have taken steps to comply with the GDPR, including reviewingenhancing our security procedures, updating our website, revising our clinical trial informed consents, and entering into data processing agreements with relevant contractors, we cannot assure you that our efforts to remain in compliance will be fully successful. The GDPR and other changes in laws or regulations associated with the enhanced protection of personal data may increase our costs of compliance and result in greater legal risks.

Foreign currency exchange rates may adversely affect our results.

Due to our operations outside of the United States, we are exposed to market risk, related to changes in foreign currency exchange rates. Historically, we have not hedged our foreign currency exposure. Changes in the relative values of currencies occur regularly and, in some instances, could materially adversely affect our business, our financial condition, the results of our operations or our cash flows.

For the years ended December 31, 20202021 and 2019,2020, changes in foreign currency exchange rates did not have a material impact on our historical financial position, our business, our financial condition, the results of our operations or our cash flows. A hypothetical 10% change in foreign currency rates would not have a material impact on our historical financial position or results of operations. However, there can be no assurance that changes in foreign currency exchange rates will not have a material adverse impact on us in the future.

The effectsU.S. tax legislation and future changes to applicable U.S. or foreign tax laws and regulations may have a material adverse effect on our business, financial condition and results of operations.

We are subject to income and other taxes in the United States and foreign jurisdictions. Changes in laws and policy relating to taxes or trade, including increases in tax rates or modifications, technical corrections or clarifications to tax laws, such as the Tax Cuts and Jobs Act, may have an adverse effect on our business, financial condition and results of operations. This Annual Report on Form 10-K does not discuss any such tax legislation or changes to tax laws and legislation, or the manner in which it might affect us or purchasers of our securities. We urge our investors to consult with their legal and tax advisors with respect to such legislation and the potential tax consequences of investing in our securities. 

We are also subject to different tax regulations in each of the jurisdictions where we conduct our business or where our management is located. We expect the scope and extent of regulation in the jurisdictions in which we conduct our business, or where our management is located, as well as regulatory oversight and supervision, to generally continue to increase. Generally, future changes in applicable U.S. or foreign tax laws and regulations, or their interpretation and application could adversely affecthave an adverse effect on our business, financial condition and financial conditions.

The Tax Cuts and Jobs Act (the “Tax Act”) significantly reformed the Internal Revenue Coderesults of 1986, as amended. The Tax Act, among other things, included changes to U.S. federal tax rates, imposed significant additional limitations on the deductibility of interest and net operating loss carryforwards, allowed for the expensing of capital expenditures, and put into effect the migration from a “worldwide” system of taxation to a territorial system. These changes and other aspects of the Tax Act remain subject to developing interpretation and clarification. Further, the new administration could introduce modifications, technical corrections or clarifications to the Tax Act or other changes in tax laws. Increases in tax rates or modifications and changes in tax laws, including the Tax Act, could materially and adversely affect our business and financial conditions.operations.

Inadequate funding for the FDA, the SEC and other government agencies, or a work slowdown or stoppage at those agencies as part of a broader federal government shutdown, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner, or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, the ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, including beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and the SEC, have had to furlough critical FDA, SEC and other government employees and stop critical activities. Additionally, the FDA and regulatory authorities outside the United States have imposed and may continue to impose various restrictions or other policy measures in response to the COVID-19 pandemic.  If a prolonged government shutdown or slowdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

Risks Related to Our Intellectual Property

If we are not able to obtain and enforce market exclusivity for our technologies or product candidates, development and commercialization of our product candidates may be adversely affected.

In our industry, the majority of an innovative product’s commercial value is usually realized during the period in which it has market exclusivity. Market exclusivity is comprised of both patent and other intellectual property protection, as well as regulatory exclusivity.

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In the United States and some other countries, when market exclusivity expires and generic versions of a product are approved and marketed, there usually are very substantial and rapid declines in the product’s sales. Accordingly, our success depends in part on our ability to obtain and maintain patents and other forms of intellectual property rights, including trademarks, trade secrets and in-licenses of intellectual property rights of others, for our product candidates and platform technologies, methods used to manufacture our product candidates, methods of patient stratification and methods for treating patients using our product candidates, as well as our ability to preserve our trade secrets, to prevent third parties from infringing upon our proprietary rights and to operate without infringing upon the proprietary rights of others. Certain research and development activities involved in pharmaceutical development are exempt from patent infringement in the United States and other jurisdictions, for example, in the U.S.United States by the provisions of 35 U.S.C. § 271(e)(1) (the “Safe Harbor”). However, in the U.S.United States and certain other jurisdictions, the Safe Harbor exemption terminates when the sponsor submits an application for marketing approval (e.g., a New Drug Application (“NDA”) in the U.S.)United States). Therefore, the risk that a third party might allege patent infringement may increase as our products approach commercialization. We may not be able to apply for patents or obtain patent protection on certain aspects of our product candidates or our platform in a timely fashion or at all. Our existing issued and granted patents and any future patents we obtain may not be sufficiently broad to prevent others from using our technology or from developing competing products and technology. There is no guarantee that any of our pending patent applications will result in issued or granted patents, that any of our issued or granted patents will not later be found to be invalid or unenforceable, or that any issued or granted patents will include claims that are sufficiently broad to cover our product candidates, our platform technologies, or any methods relating to them, or to provide meaningful protection from our competitors. Moreover, the patent position of biotechnology and pharmaceutical companies can be highly uncertain and involves complex legal and factual questions. We will be able to protect our proprietary rights from unauthorized use by third parties only to the extent that our current and future proprietary technology and product candidates are covered by valid and enforceable patents or are effectively maintained as trade secrets. If third parties disclose or misappropriate our proprietary rights, it may materially and adversely impact our position in the market.

Legal issues related to the patentability of biopharmaceuticals, and methods of their manufacture and use, are complex and uncertain in some countries. In some countries, applicants are not able to protect methods of treating human beings or medical treatment processes. Intellectual property protection varies throughout the world and is subject to change over time. Certain jurisdictions have enacted various rules and laws precluding issuance of patents encompassing any methods a doctor may practice on a human being or any other animal to treat a disease or condition. Further, many countries have enacted laws and regulatory regimes that do not allow patent protection for methods of use of known compounds. Particularly given that some of our product candidates may represent stereopure versions of previously described oligonucleotides, it may be difficult or impossible to obtain patent protection for them in relevant jurisdictions. Thus, in some countries and jurisdictions, it may not be possible to patent some of our product candidates at all. In some countries and jurisdictions, only composition claims may be obtained, and only when those compositions are or contain compounds that are new and/or novel. Also, patents issued with composition claims (i.e., covering product candidates) cannot always be enforced to protect methods of using those compositions to treat or diagnose diseases or medical conditions. In such countries or jurisdictions, enforcement of patents to protect our product candidates, or their uses, may be difficult or impossible. Lack of patent protection in such cases may have a materially adverse effect on our business and financial condition.

Furthermore, given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates, their manufacture or their use might expire before or shortly after those candidates receive regulatory approval and are commercialized. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours. We expect to seek extensions of patent terms where these are available upon regulatory approval in those countries where we are prosecuting patents. This includes in the United States under the Drug Price Competition and Patent Term Restoration Act of 1984, which permits a patent term extension of up to five years

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beyond the expiration of the patent. However, the applicable authorities, including the FDA in the United States, and any equivalent regulatory authority in other countries, may not agree with our assessment of whether such extensions are available, and may refuse to grant extensions to our patents, or may grant more limited extensions than we request. If this occurs, our competitors may take advantage of our investment in development and clinical trials by referencing our clinical and preclinical data and launch their product earlier than might otherwise be possible.

The U.S. Patent and Trademark Office (“USPTO”) and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other provisions during the patent prosecution process. There are situations in which noncompliance can result in abandonment or lapse of a patent or patent application, or loss of right to enforce patent claims, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such an event, competitors might be able to enter the market earlier than would otherwise have been the case. The standards applied by the USPTO and foreign patent offices in granting patents are not uniform, can vary substantially from country to country, and are not always applied predictably, requiring country-specific patent expertise in each jurisdiction in which patent protection is sought. For example, there is no uniform worldwide policy regarding patentable subject matter or the scope of claims allowable in biotechnology and pharmaceutical patents. As such, we do not know the degree of future protection that we will have on our proprietary products and technologies. While we will endeavor to try to protect our product candidates and platform technology with intellectual property rights such as patents, as appropriate, the process of filing and prosecuting patent applications, and obtaining, maintaining and defending patents is time-consuming, expensive, uncertain, and sometimes unpredictable.

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In addition, there are numerous recent changes to the patent laws and proposed changes to the rules of the USPTO that may have a significant impact on our ability to protect our technology and enforce our intellectual property rights. For example, the America Invents Act, enacted within the last several years, involves significant changes in patent legislation. The U.S. Supreme Court has ruled on several patent cases in recent years, some of which cases either narrow the scope of patent protection available in certain circumstances or weaken the rights of patent owners in certain situations. The decision by the U.S. Supreme Court in Association forMolecular Pathology v. Myriad Genetics, Inc. precludes a claim to a nucleic acid having a stated nucleotide sequence which is identical to a sequence found in nature and unmodified. We currently are not aware of an immediate impact of this decision on our patents or patent applications because we are developing oligonucleotides which contain modifications that we believe are not found in nature. However, this decision has yet to be clearly interpreted by courts and by the USPTO. We cannot make assurances that the interpretations of this decision or subsequent rulings will not adversely impact our patents or patent applications. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on decisions by the U.S. Congress, the federal courts and the USPTO, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future.

Once granted, patents may remain open to opposition, interference, re-examination, post-grant review, inter partes review, nullification or derivation action in court or before patent offices or similar proceedings for a given period after allowance or grant, during which time third parties can raise objections against such initial grant. In the course of such proceedings, which may continue for a protracted period of time, the patent owner may be compelled to limit the scope of the allowed or granted claims attacked or may lose the allowed or granted claims altogether. In addition, there can be no assurance that:

We license patent rights from third-party owners or licensees. If such owners or licensees do not properly or successfully obtain, maintain or enforce the patents underlying such licenses, or if they retain or license to others any competing rights, our competitive position and business prospects may be adversely affected.

We license patent rights from third parties that we may use from time to time to protect certain aspects of our technology and programs. We may license additional third-party intellectual property in the future. To the extent that we use, and ultimately rely on, in-licensed technologies in our platform and our programs, our success will depend in part on the ability of our licensors to obtain, maintain and enforce patent protection for those in-licensed technologies. Our licensors may not successfully prosecute the patent applications licensed to us. Even if patents issue or are granted, our licensors may fail to maintain these patents, may determine not to pursue litigation against other companies that are infringing these patents, or may pursue litigation less aggressively than we would. Further, we may not obtain exclusive rights, which would allow for third parties to develop competing products. Without protection for, or exclusive right to, the intellectual property we license, other companies might be able to offer substantially identical products for sale, which could adversely affect our competitive business position and harm our business prospects. In addition, we may sublicense our rights under our third-party licenses to current or future collaborators or any future strategic partners. Any impairment of these sublicensed rights could result in reduced revenue under any future collaboration agreements we may enter into or result in termination of an agreement by one or more of our current or future collaborators or any future strategic partners.

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Other companies or organizations may challenge our or our licensors’ patent rights or may assert patent rights that prevent us from developing and commercializing our products.

Nucleic acid therapeutics is a relatively new scientific field, the commercial exploitation of which has resulted in many different patents and patent applications from organizations and individuals seeking to obtain patent protection in the field. We have obtained grants and issuances of patents in this field. The issued patents and pending patent applications in the United States and in key markets around the world that we own or license claim certain methods, compositions and processes relating to the discovery, development, manufacture and/or commercialization of oligonucleotides and/or our platform.

As the field of oligonucleotides matures, patent applications are being processed by national patent offices around the world. There is uncertainty about which patents will issue, and, if they do, as to when, to whom, and with what claims. It is likely that there will be significant litigation in the courts and other proceedings, such as interference, reexamination and opposition proceedings, in various patent offices relating to patent rights in the oligonucleotides field. In many cases, the possibility of appeal or opposition exists for either us or our opponents, and it may be years before final, unappealable rulings are made with respect to these patents in certain jurisdictions. The timing and outcome of these and other proceedings is uncertain and may adversely affect our business, particularly if we are not successful in defending the patentability and scope of our pending and issued patent claims or if third parties are successful in obtaining claims that cover any of our product candidates or our platform. In addition, third parties may attempt to invalidate our intellectual property rights. Even if our rights are not directly challenged, invalidated or circumvented, disputes could lead to the weakening of our intellectual property rights. Our defense against any attempt by third parties to challenge, invalidate, circumvent or weaken our intellectual property rights could be costly to us, could require significant time and attention of our management and could adversely affect our business and our ability to successfully compete in the field of oligonucleotides.

We may not be able to protect our intellectual property rights throughout the world.

Obtaining a valid and enforceable issued or granted patent covering our technology in the United States and worldwide can be extremely costly. In jurisdictions where we have not obtained patent protection, competitors may use our technology to develop their own products and further, may export otherwise infringing products to territories where we have patent protection, but where it is more difficult to enforce a patent as compared to the United States. Competitor products may compete with our future products in jurisdictions where we do not have issued or granted patents or where our issued or granted patent claims or other intellectual property rights are not sufficient to prevent competitor activities in these jurisdictions. The legal systems of certain countries, particularly certain developing countries, make it difficult to enforce patents and such countries may not recognize other types of intellectual property protection, particularly relating to biopharmaceuticals. This could make it difficult for us to prevent the infringement of our patents or marketing of competing products in violation of our proprietary rights generally in certain jurisdictions. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial cost and divert our efforts and attention from other aspects of our business.

We generally file a provisional patent application first (a priority filing) at the USPTO. A Patent Cooperation Treaty (“PCT”) application is usually filed within 12 months after the priority filing. Regional and/or national patent applications may be pursued outside of the United States, either based on a PCT application or as a direct filing, in some cases claiming priority to a prior U.S. or

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PCT filing. Some of our cases have been filed in multiple jurisdictions, including major market jurisdictions. We also commonly enter the national stage in the United States through a PCT filing. We have so far not filed for patent protection in all national and regional jurisdictions where such protection may be available. In addition, we may decide to abandon national and regional patent applications before grant. Finally, the grant proceeding of each national or regional patent is an independent proceeding which may lead to situations in which applications might in some jurisdictions be refused by the relevant registration authorities, while granted by others. It is also quite common that depending on the country, different scopes of patent protection may be granted on the same product or technology.

The laws of some jurisdictions do not protect intellectual property rights to the same extent as the laws in the United States, and many companies have encountered significant difficulties in protecting and defending such rights in such jurisdictions. If we or our licensors encounter difficulties in protecting, or are otherwise precluded from effectively protecting, the intellectual property rights important for our business in such jurisdictions, the value of these rights may be diminished and we may face additional competition from others in those jurisdictions. Many countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties, allowing competitors to manufacture and sell their own versions of our product, thereby reducing our sales. In addition, many countries do not permit enforcement of patents, or limit the enforceability of patents against government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such a patent. If we or any of our licensors, collaborators or present or future partners are forced to grant a license to third parties with respect to any patents relevant to our business, our competitive position in the relevant jurisdiction may be impaired and our business and results of operations may be adversely affected.

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The requirements for patentability may differ in certain countries. For example, some jurisdictions may have heightened requirements for patentability compared to others, and may specifically require a detailed description of medical uses of a claimed drug. In some jurisdictions, unlike the United States, there is no link between regulatory approval of a drug and its patent status. Furthermore, generic or biosimilar drug manufacturers or other competitors may challenge the scope, validity or enforceability of our or our licensors’ or collaborators’ patents, requiring us or our licensors or collaborators to engage in complex, lengthy and costly litigation or other proceedings. Generic or biosimilar drug manufacturers may develop, seek approval for, and launch generic versions of our products. Accordingly, our and our licensors’ and collaborators’ efforts to enforce intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we own or license.

We or our licensors, collaborators or any future strategic partners may become subject to third party claims or litigation alleging infringement of patents or other proprietary rights or seeking to invalidate patents or other proprietary rights, and we may need to resort to litigation to protect or enforce our patents or other proprietary rights, all of which could be costly and time consuming, or delay or prevent the development and commercialization of our product candidates, or put our patents and other proprietary rights at risk.

We or our licensors, collaborators or any future strategic partners may be subject to third-party claims for infringement or misappropriation of patent or other proprietary rights. We are generally obligated under our license or collaboration agreements to indemnify and hold harmless our licensors or collaborators for damages arising from intellectual property infringement by us. If we or our licensors, collaborators or any future strategic partners are found to infringe a third-party patent or other intellectual property rights, we could be required to pay damages, potentially including treble damages, if we are found to have willfully infringed. In addition, we or our licensors, collaborators or any future strategic partners may choose to seek, or be required to seek, a license from a third party, which may not be available on acceptable terms, if at all. Even if a license can be obtained on acceptable terms, the rights may be non-exclusive, which could give our competitors access to the same technology or intellectual property rights licensed to us. If we fail to obtain a required license, we or our collaborator, or any future collaborator, may be unable to effectively market product candidates based on our technology, which could limit our ability to generate revenue or achieve profitability and possibly prevent us from generating revenue sufficient to sustain our operations. In addition, we may find it necessary to pursue claims or initiate lawsuits to protect or enforce our patent or other intellectual property rights. The cost to us in defending or initiating any litigation or other proceeding relating to patent or other proprietary rights, even if resolved in our favor, could be substantial, and litigation would divert our management’s attention. Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could delay our research and development efforts and limit our ability to continue our operations.

If we were to initiate legal proceedings against a third party to enforce a patent covering one of our products or our technology, the defendant could counterclaim that our patent is invalid or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, for example, lack of novelty, lack of written disclosure, obviousness, or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the USPTO, or made a misleading statement, during prosecution. The outcome following legal allegations of invalidity and unenforceability during patent litigation is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we and the patent examiner were unaware during prosecution. If a

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defendant were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on one or more of our products or certain aspects of our platform technology. Such a loss of patent protection could negatively impact our business. Patents and other intellectual property rights also will not protect our technology if competitors design around our protected technology without legally infringing our patents or other intellectual property rights.

Intellectual property rights of third parties could adversely affect our ability to commercialize our product candidates, and we might be required to litigate or obtain licenses from third parties in order to develop or market our product candidates. Such litigation or licenses could be costly or not available on commercially reasonable terms.

Because the oligonucleotide intellectual property landscape is still evolving and our product candidates have not yet reached commercialization, it is difficult to conclusively assess our freedom to operate. There are numerous companies that have pending patent applications and issued patents directed to certain aspects of oligonucleotides. We are aware of third-party competitors in the oligonucleotide therapeutics space, whose patent filings and/or issued patents may include claims directed to targets and/or products related to some of our programs. It is possible that at the time that we commercialize our products these third-party patent portfolios may include issued patent claims that cover our products or critical features of their production or use. Our competitive position may suffer if patents issued to third parties or other third-party intellectual property rights cover, or may be alleged to cover, our products or elements thereof, or methods of manufacture or use relevant to our development plans. In such cases, we may not be in a position to develop or commercialize product candidates unless we successfully pursue litigation to nullify or invalidate the third party intellectual property right concerned or enter into a license agreement with the intellectual property right holder, if available on commercially reasonable terms.

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It is also possible that we have failed to identify relevant third-party patents or applications. For example, U.S. applications filed before November 29, 2000, and certain U.S. applications filed after that date that will not be filed outside the United States remain confidential until patents issue. Patent applications in the United States and elsewhere are published approximately 18 months after the earliest filing date for which priority is claimed, with such earliest filing date being commonly referred to as the priority date. Therefore, patent applications covering our products or platform technology could have been filed by others without our knowledge. Additionally, pending patent applications which have been published can, subject to certain limitations, be later amended in a manner that could cover our platform technologies, our products or the use of our products. Third party intellectual property right holders may also actively bring infringement claims against us. We cannot guarantee that we will be able to successfully settle or otherwise resolve such infringement claims. If we are unable to successfully settle future claims on terms acceptable to us, we may be required to engage in or continue costly, unpredictable and time-consuming litigation and may be prevented from or experience substantial delays in marketing our products. If we fail in any such dispute, in addition to being forced to pay damages, we may be temporarily or permanently prohibited from commercializing any of our product candidates that are held to be infringing. We might, if possible, also be forced to redesign product candidates so that we no longer infringe the third-party intellectual property rights. Any of these events, even if we were ultimately to prevail, could require us to divert substantial financial and management resources that we would otherwise be able to devote to our business.

If we fail to comply with our obligations under any license, collaboration or other agreement, we may be required to pay damages and could lose intellectual property rights that are necessary for developing and protecting our product candidates, or we could lose certain rights to grant sublicenses.

There are many issued patents and/or pending patent applications that claim aspects of oligonucleotide compositions, chemistry and/or modifications that we may want or need to apply to our product candidates. There are also many issued patents and/or pending patent applications that claim targeted genes or portions of genes that may be relevant for the oligonucleotides we wish to develop. We are aware of third-party competitors in the oligonucleotide therapeutics space whose patent filings and/or issued patents may include claims directed to targets and/or product candidates related to some of our development programs. It is possible that these third-party patent portfolios may include issued patent claims that cover our product candidates or critical features of their production or use. Thus, it is possible that one or more organizations will hold patent rights to which we will need or want a license. If those organizations refuse to grant us a license to such patent rights on reasonable terms, or at all, we may not be able to market products or perform research and development or other activities covered by these patents.

Our technology licenses and any future licenses we enter into are likely to impose various development, commercialization, funding, milestone, royalty, diligence, sublicensing, insurance, patent prosecution and enforcement, and/or other obligations on us. If we breach any of these imposed obligations, or use the intellectual property licensed to us in an unauthorized manner, we may be required to pay damages and the licensor may have the right to terminate the license, which could result in us being unable to develop, manufacture and sell products that are covered by the licensed technology or enable a competitor to gain access to the licensed technology. Moreover, our licensors may own or control intellectual property that has not been licensed to us and, as a result, we may be subject to claims, regardless of their merit, that we are infringing or otherwise violating the licensor’s rights. In addition, while we cannot currently determine the amount of the royalty obligations we would be required to pay on sales of future products, if any, the amounts may be significant. The amount of our future royalty obligations will depend on the technology and intellectual property we use in

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products that we successfully develop and commercialize, if any. Therefore, even if we successfully develop and commercialize products, we may be unable to achieve or maintain profitability.

If we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.

In addition to seeking patent protection for certain aspects of our product candidates, we also consider trade secrets, including confidential and unpatented know-how, improvements and technological innovation important to the maintenance of our competitive position. We protect trade secrets and confidential and unpatented know-how, improvements and technological innovation, in part, by entering into non-disclosure and confidentiality agreements with parties who have access to such knowledge, such as our employees, corporate collaborators, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and other third parties. We also enter into confidentiality and invention or patent assignment agreements with our employees and consultants that obligate them to maintain confidentiality and assign their inventions to us. Despite these efforts, any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts in the United States and certain foreign jurisdictions are less willing or unwilling to protect trade secrets. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor, we would have no right to prevent them from using that technology or information to compete with us. If any of our trade secrets were to be disclosed to or independently developed by a competitor, our competitive position would be harmed.

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We may be subject to claims that we or our employees or consultants have wrongfully used or disclosed alleged trade secrets of our employees’ or consultants’ former employers or their clients. These claims may be costly to defend and if we do not successfully do so, we may be required to pay monetary damages and may lose valuable intellectual property rights or personnel.

Many of our employees were previously employed at universities or biotechnology or pharmaceutical companies, including our competitors or potential competitors. Although no claims against us are currently pending, we may be subject to claims that these employees or we have inadvertently or otherwise used or disclosed trade secrets or other proprietary information of their former employers. Litigation may be necessary to defend against these claims. If we fail in defending such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. A loss of key research personnel or their work product could hamper our ability to commercialize, or prevent us from commercializing, our product candidates, which could severely harm our business. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to management.

If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.

Our trademarks or trade names may be infringed, challenged, invalidated, circumvented, weakened or declared generic or determined to be infringing on other marks. We may not be able to protect our rights to these trademarks and trade names or may be forced to stop using these names, which we need for name recognition by potential partners or customers in our markets of interest. If we are unable to establish name recognition based on our trademarks and trade names, we may not be able to compete effectively and our business may be adversely affected.

Risks Related to Our Being a Singapore Company

We are a Singapore incorporated company and it may be difficult to enforce a judgment of U.S. courts for civil liabilities under U.S. federal securities laws against us, our directors or our officers in Singapore.

We are incorporated under the laws of the Republic of Singapore, and certain of our directors are residents outside the United States. Moreover, a significant portion of our consolidated assets are located outside the United States. Although we are incorporated outside the United States, we have agreed to accept service of process in the United States through our agent designated for that purpose. Nevertheless, because a majority of the consolidated assets owned by us are located outside the United States, any judgment obtained in the United States against us may not be enforceable within the United States.

There is no treaty between the United States and Singapore providing for the reciprocal recognition and enforcement of judgments in civil and commercial matters and a final judgment for the payment of money rendered by any federal or state court in the United States based on civil liability, whether or not predicated solely upon the federal securities laws, would, therefore, not be automatically enforceable in Singapore. There is uncertainty as to whether judgments of courts in the United States based upon the civil liability provisions of the federal securities laws of the United States would be recognized or enforceable in Singapore. In addition, holders of book-entry interests in our shares will be required to be registered shareholders as reflected in our shareholder register in order to have standing to bring a shareholder action and, if successful, to enforce a foreign judgment against us, our directors or our executive officers in the Singapore courts. The administrative process of becoming a registered holder could result in delays prejudicial to any

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legal proceedings or enforcement action. Consequently, it may be difficult for investors to enforce against us, our directors or our officers in Singapore judgments obtained in the United States which are predicated upon the civil liability provisions of the federal securities laws of the United States.

We are incorporated in Singapore and our shareholders may have more difficulty in protecting their interests than they would as shareholders of a corporation incorporated in the United States.

Our corporate affairs are governed by our constitution and by the laws governing corporations incorporated in Singapore. The rights of our shareholders and the responsibilities of the members of our board of directors under Singapore law are different from those applicable to a corporation incorporated in the United States. Principal shareholders of Singapore companies do not owe fiduciary duties to minority shareholders, as compared, for example, to controlling shareholders in corporations incorporated in Delaware. Our public shareholders may have more difficulty in protecting their interests in connection with actions taken by our management, members of our board of directors or our principal shareholders than they would as shareholders of a corporation incorporated in the United States.

In addition, only persons who are registered as shareholders in our shareholder register are recognized under Singapore law as shareholders of our company. Only registered shareholders have legal standing to institute shareholder actions against us or otherwise seek to enforce their rights as shareholders. Investors in our shares who are not specifically registered as shareholders in our shareholder register (for example, where such shareholders hold shares indirectly through the Depository Trust Company) are required to become registered as shareholders in our shareholder register in order to institute or enforce any legal proceedings or claims against

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us, our directors or our executive officers relating to shareholder rights. Holders of book-entry interests in our shares may become registered shareholders by exchanging their book-entry interests in our shares for certificated shares and being registered in our shareholder register. Such process could result in administrative delays which may be prejudicial to any legal proceeding or enforcement action.

We are subject to the laws of Singapore, which differ in certain material respects from the laws of the United States.

As a company incorporated under the laws of the Republic of Singapore, we are required to comply with the laws of Singapore, certain of which are capable of extra-territorial application, as well as our constitution. In particular, we are required to comply with certain provisions of the Securities and Futures Act 2001 of Singapore (Cap 289) (the “SFA”), which prohibit certain forms of market conduct and require certain information disclosures, and impose criminal and civil penalties on corporations, directors and officers in respect of any breach of such provisions. We are required to comply with the Singapore Code on Take-Overs and Mergers (the “Singapore Takeover Code”), which specifies, among other things, certain circumstances in which a general offer is to be made upon a change in effective control, and further specifies the manner and price at which voluntary and mandatory general offers are to be made.

We are also subject to Section 34 of the Singapore Patents Act, which provides that a person residing in Singapore is required to obtain written authorization from the Singapore Registrar of Patents (the “Registrar”) before filing an application for a patent for an invention outside of Singapore, unless certain conditions have been satisfied. A violation of Section 34 is a criminal offense punishable by a fine not exceeding S$5,000, or imprisonment for a term not exceeding two years, or both. There have been some instances where we have undertaken filings outside of Singapore, and there may be instances where we are required to make such filings in the future, without first obtaining written authorization from the Registrar. We have notified the Registrar of such filings and we have since implemented measures to address the requirements of Section 34 moving forward. To date, the Registrar has offered a compound of some of the offences considered against payment of a sum of S$50 to S$ 100150 per considered case. Under Singapore law, the Registrar has discretion to offer a compound of such offences against payment of a sum of money of up to S$2,000, or to prosecute the offence subject to the other penalties noted above. There remainPer requests in the Registrar’s most recent decision, we have submitted approximately 40140 patent applications in multiple patent families, most of which we have notifiedare related to previously reported applications, to the Intellectual Property Office of Singapore (“IPOS”). The IPOS may consider the filing of wheresome or all of these applications to have breached Section 34 requirements have not been complied with,per IPOS’ current interpretation of Section 34, and we are pendingwaiting for IPOS’ decision thereon.on these applications. We cannot assure you that the Registrar will offer to compound any such violations of Section 34, or that any offer to compound will be for an amount similar to previous compound offers.offer.

The laws of Singapore and of the United States differ in certain significant respects. The rights of our shareholders and the obligations of our directors and officers under Singapore law (including under the Companies Act 1967 of Singapore (Cap 50) (the “Singapore Companies Act”) are different from those applicable to a company incorporated in the State of Delaware in material respects, and our shareholders may have more difficulty and less clarity in protecting their interests in connection with actions taken by our management, members of our board of directors or our controllingaffiliated shareholders than would otherwise apply to a company incorporated in the State of Delaware.

The application of Singapore law, in particular, the Singapore Companies Act may, in certain circumstances, impose more restrictions on us and our shareholders, directors and officers than would otherwise be applicable to a company incorporated in the State of

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Delaware. For example, the Singapore Companies Act requires directors to act with a reasonable degree of diligence and, in certain circumstances, imposes criminal liability for specified contraventions of particular statutory requirements or prohibitions. In addition, pursuant to the provisions of the Singapore Companies Act, shareholders holding 10% or more of the total number of paid-up shares carrying the right of voting in general meetings may require the convening of an extraordinary general meeting of shareholders by our directors. If our directors fail to comply with such request within 21 days of the receipt thereof, the original requisitioning shareholders, or any of them holding more than 50% of the voting rights represented by the original requisitioning shareholders, may proceed to convene such meeting, and we will be liable for the reasonable expenses incurred by such requisitioning shareholders. We are also required by the Singapore Companies Act to deduct such corresponding amounts from fees or other remuneration payable by us to such non-complying directors.

We are subject to the Singapore Takeover Code, which requires a person acquiring 30% or more of our voting shares to conduct a takeover offer for all of our voting shares. This could have the effect of discouraging, delaying or preventing a merger or acquisition and limit the market price of our ordinary shares.

We are subject to the Singapore Takeover Code. The Singapore Takeover Code contains provisions that may delay, deter or prevent a future takeover or change in control of our company and limit the market price of our ordinary shares for so long as we remain a public company with more than 50 shareholders and net tangible assets of S$5 million (Singapore dollars) or more. For example, under the Singapore Takeover Code, any person acquiring, whether by a series of transactions over a period of time or not, either on such person’s own or together with parties acting in concert with such person, 30% or more of our voting shares, or if such person holds, either on such person’s own or together with parties acting in concert with such person, between 30% and 50% (both inclusive) of our voting shares, and if such person (or parties acting in concert with such person) acquires additional voting shares representing

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more than 1% of our voting shares in any six-month period, must, except with the consent of Securities Industry Council in Singapore, extend a takeover offer for our remaining voting shares in accordance with the Singapore Takeover Code. Therefore, any investor seeking to acquire a significant stake in our company may be deterred from doing so if, as a result, such investor would be required to conduct a takeover offer for all of our voting shares.

These same provisions could discourage potential investors from acquiring a stake or making a significant investment in our company and may substantially impede the ability of our shareholders to benefit from a change of effective control and, as a result, may adversely affect the market price of our ordinary shares and the ability to realize any benefits from a potential change of control.

For a limited period of time, our directors have general authority to allot and issue new ordinary shares on terms and conditions and for such purposes as may be determined by our board of directors in its sole discretion.

Under Singapore law, we may only allot and issue new shares with the prior approval of our shareholders in a general meeting. At our most recent annual general meeting of shareholders, our shareholders provided our directors with a general authority, subject to the provisions of the Singapore Companies Act and our constitution, to allot and issue any number of new ordinary shares and/or make or grant offers, agreements, options or other instruments (including the grant of awards or options pursuant to our equity-based incentive plans and agreements in effect from time to time) that might or would require ordinary shares to be allotted and issued (collectively, the “Instruments”); and unless revoked or varied by the Companyus in a general meeting, such authority will continue in force until the earlier of (i) the conclusion of our next annual general meeting of shareholders, or (ii) the expiration of the period within which our next annual general meeting of shareholders is required by law to be held. Subject to the general requirements of the Singapore Companies Act and our constitution, the general authority given to our directors by our shareholders to allot and issue ordinary shares and/or make or grant the Instruments may be exercised by our directors on such terms and conditions, for such purposes and for consideration as they may in their sole discretion deem fit, and with such rights or restrictions as they may think fit to impose and as are set forth in our constitution. Any additional issuances of new ordinary shares and/or any grant of the Instruments by our directors may dilute our shareholders’ interests in our ordinary shares and/or adversely impact the market price of our ordinary shares.

We may be or become a passive foreign investment company, which could result in adverse U.S. federal income tax consequences to U.S. Holders.

The rules governing passive foreign investment companies (“PFICs”) can have adverse effects for U.S. federal income tax purposes. The tests for determining PFIC status for a taxable year depend upon the relative values of certain categories of assets and the relative amounts of certain kinds of income. The determination of whether we are a PFIC, which must be made annually after the close of each taxable year, depends on the particular facts and circumstances (such as the valuation of our assets, including goodwill and other intangible assets) and may also be affected by the application of the PFIC rules, which are subject to differing interpretations. The fair market value of our assets is expected to relate, in part, to (a) the market price of our ordinary shares and (b) the composition of our income and assets, which will be affected by how, and how quickly, we spend any cash that is raised in any financing transaction. Moreover, our ability to earn specific types of income that we currently treat as non-passive for purposes of the PFIC rules is uncertain with respect to future years. Because the value of our assets for purposes of determining PFIC status will depend in part on the market

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price of our ordinary shares, which may fluctuate significantly, there can be no assurance that we will not be considered a PFIC for our current taxable year ending December 31, 20212022 or for any future taxable year.

If we are a PFIC, a U.S. Holder (defined below) would be subject to adverse U.S. federal income tax consequences, such as ineligibility for any preferred tax rates on capital gains or on actual or deemed dividends, interest charges on certain taxes treated as deferred, and additional reporting requirements under U.S. federal income tax laws and regulations. A U.S. Holder may in certain circumstances mitigate adverse tax consequences of the PFIC rules by filing an election to treat the PFIC as a qualified electing fund (“QEF”) or, if shares of the PFIC are “marketable stock” for purposes of the PFIC rules, by making a mark-to-market election with respect to the shares of the PFIC. We do not intend to comply with the reporting requirements necessary to permit U.S. Holders to elect to treat us as a QEF. If a U.S. Holder makes a mark-to-market election with respect to its ordinary shares, the U.S. Holder is required to include annually in its U.S. federal taxable income an amount reflecting any year end increase in the value of its ordinary shares. For purposes of this discussion, a “U.S. Holder” is a beneficial owner of ordinary shares that is for U.S. federal income tax purposes: (i) an individual who is a citizen or resident of the United States; (ii) a corporation (or other entity taxable as a corporation for U.S. federal income tax purposes) created or organized in or under the laws of the United States, any state thereof or the District of Columbia; (iii) an estate the income of which is subject to U.S. federal income taxation regardless of its source; or (iv) a trust (a) if a court within the U.S. can exercise primary supervision over its administration, and one or more U.S. persons have the authority to control all of the substantial decisions of that trust, or (b) that was in existence on August 20, 1996, and validly elected under applicable Treasury Regulations to continue to be treated as a domestic trust.

Investors should consult their own tax advisors regarding all aspects of the application of the PFIC rules to the ordinary shares.

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Singapore taxes may differ from the tax laws of other jurisdictions.

Prospective investors should consult their tax advisors concerning the overall tax consequences of purchasing, owning and disposing of our shares. Singapore tax law may differ from the tax laws of other jurisdictions, including the United States.

We may become subject to unanticipated tax liabilities.

We are incorporated under the laws of Singapore. We are, however, subject to income, withholding or other taxes in certain jurisdictions by reason of our activities and operations, and it is also possible that tax authorities in any such jurisdictions could assert that we are subject to greater taxation than we currently anticipate. Any such non-Singaporean tax liability could materially adversely affect our results of operations.

Tax authorities could challenge the allocation of income and deductions among our subsidiaries, which could increase our overall tax liability.

We are organized in Singapore, and we currently have subsidiaries in the United States, Japan, the United Kingdom, and Ireland. As we grow our business, we conduct, and expect to continue to conduct, increased operations through our subsidiaries in various jurisdictions. If two or more affiliated companies are located in different jurisdictions, the tax laws or regulations of each country generally will require transactions between those affiliated companies to be conducted on terms consistent with those between unrelated companies dealing at arms’ length, and appropriate documentation generally must be maintained to support the transfer prices. We maintain our transfer pricing policies to be compliant with applicable transfer pricing laws, but our transfer pricing procedures are not binding on applicable tax authorities.

If tax authorities were to successfully challenge our transfer pricing, there could be an increase in our overall tax liability, which could adversely affect our financial condition, results of operations and cash flows. In addition, the tax laws in the jurisdictions in which we operate are subject to differing interpretations. Tax authorities may challenge our tax positions, and if successful, such challenges could increase our overall tax liability. In addition, the tax laws in the jurisdictions in which we operate are subject to change. We cannot predict the timing or content of such potential changes, and such changes could increase our overall tax liability, which could adversely affect our financial condition, results of operations and cash flows.

Our financial results reflect the effect of certain tax credits and the operation of certain tax regimes within the United Kingdom. Recently proposedenacted legislation in the United Kingdom maywill limit the amount we may be able to claim as a payable tax credit in the future which could impact our financial condition, results of operations and cash flows.

We benefit from the U.K. research and development tax credit regime for small and medium sized companies, whereby our subsidiary in the United Kingdom is able to surrender the trading losses that arise from its research and development activities for a payable tax credit of up to 33.4% of eligible research and development expenditure on staff and consumables. Expenditure of staff supplied by unconnected third parties are eligible for a cash rebate of up to 21.7%.

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Due to a recently proposedenacted change in the U.K. legislation affecting the U.K. research and development tax credit regime for small and medium sized companies, our ability to receive a payable tax credit for the surrender of our trading losses from research and development activities incurred from taxable years beginning on or after April 1, 2021 wouldwill be limited to the amount equal to three times our “pay as you earn” and U.K. national insurance tax liabilities.liabilities, absent our qualification under an exception from such limitation.

Further, we may not be able to continue to claim a U.K. tax credit for research and development tax credits under the small and medium-sized companies regime in the future if we increase our personnel and expand our business because we may no longer qualify as a small or medium-sized enterprise.

Risks Related to Our Ordinary Shares

The public market for our ordinary shares may not be liquid enough for our shareholders to sell their ordinary shares quickly or at market price, or at all.

Prior to the completion of our initial public offering, there was no public market for our ordinary shares. An active trading market for our shares may not develop or be maintained and our shareholders may not be able to sell their ordinary shares quickly or at the market price, or at all. Our executive officers, our directors and their respective affiliates, and our other significant shareholders beneficially own a significant portion of our outstanding ordinary shares, and therefore, liquidity in our ordinary shares is limited. Due to the limited liquidity in our ordinary shares, relatively small orders can have a disproportionate impact on the trading price of our shares. Further, the limited liquidity in our ordinary shares may also impair our ability to raise capital by conducting offerings of our ordinary shares and may impair our ability to enter into strategic partnerships or acquire companies or products by using our ordinary shares as consideration.

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The market price of our ordinary shares is likely to be highly volatile, and our shareholders may lose some or all of their investment.

The market price of our ordinary shares is likely to continue to be highly volatile, including in response to factors that are beyond our control. The stock market in general experiences extreme price and volume fluctuations. In particular, the market prices of securities of pharmaceutical and biotechnology companies are extremely volatile, and experience fluctuations that are often unrelated or disproportionate to the operating performance of these companies. These broad and sector-specific market fluctuations can result in extreme fluctuations in the price of our ordinary shares, regardless of our operating performance, and can cause our shareholders to lose some or all of their investment in the Company.us.

Our principal shareholders and management own a significant percentage of our ordinary shares and will be able to exert significant control over matters subject to shareholder approval.

Based on information publicly available to us as of December 31, 2020,2021, our executive officers, our directors and their respective affiliates, and our other significant shareholders beneficially own a significant portion of our outstanding ordinary shares. As a result, these shareholders, if acting together, will continue to have significant influence over the outcome of corporate actions requiring shareholder approval, including the election of directors, any merger, consolidation or sale of all or substantially all of our assets and any other significant corporate transaction. The interests of these shareholders may not be the same as or may even conflict with the interests of our other shareholders. For example, these shareholders could delay or prevent a change of control of our company, even if such a change of control would benefit our other shareholders, which could deprive shareholders of an opportunity to receive a premium for their ordinary shares as part of a sale of our company or our assets and might affect the prevailing market price of our ordinary shares. The significant concentration of share ownership may adversely affect the trading price of our ordinary shares due to investors’ perception that conflicts of interest may exist or arise.

We incur significant costs due to operating as a public company, and our management is required to devote substantial time to compliance initiatives.

As a public company, we incur significant legal, accounting and other expenses. We are subject to the reporting and other requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act, the Sarbanes-Oxley Act of 2002 or the Sarbanes-Oxley Act,(the “Sarbanes-Oxley Act”), and the Dodd-Frank Wall Street Reform and Protection Act, as well as rules subsequently adopted by the SEC and the Nasdaq Stock Market. These rules and regulations require, among other things, that we file annual, quarterly and current reports with respect to our business and financial condition and establish and maintain effective disclosure and financial controls and corporate governance practices. We expect that compliance with these rules and regulations will continue to substantially increase ourresult in substantial legal and financial compliance costs and will make some activities more time-consuming and costly, particularly as we are no longer an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012 (“the JOBS Act”).costly. Our management and other personnel devote a substantial amount of time to these compliance requirements.

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If we fail to maintain proper and effective internal controls, our ability to produce accurate and timely financial statements could be impaired, which could harm our operating results, our ability to operate our business and investors’ views of us.

We are required to comply with Section 404 of the Sarbanes-Oxley Act. Section 404 of the Sarbanes-Oxley Act requires public companies to maintain effective internal control over financial reporting. In particular, we must perform system and process evaluation and testing of our internal control over financial reporting to allow management to report on the effectiveness of our internal control over financial reporting. Ensuring that we have adequate internal financial and accounting controls and procedures in place so that we can produce accurate financial statements on a timely basis is a costly and time-consuming effort that is evaluated frequently. If we fail to maintain the effectiveness of our internal controls or fail to comply in a timely manner with the requirements of the Sarbanes-Oxley Act, or if we identify deficiencies in our internal control over financial reporting that are deemed to be material weaknesses, this could have a material adverse effect on our business. We could lose investor confidence in the accuracy and completeness of our financial reports, which could have an adverse effect on the price of our ordinary shares and we could be subject to sanctions or investigations by Nasdaq, the SEC or other regulatory authorities, which would require additional financial and management resources. In addition, if our efforts to comply with new or changed laws, regulations, and standards differ from the activities intended by regulatory or governing bodies due to ambiguities related to practice, regulatory authorities may initiate legal proceedings against us and our business may be harmed.

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The estimates and judgments we make, or the assumptions on which we rely, in preparing our consolidated financial statements could prove inaccurate.

Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP)(“U.S. GAAP”). The preparation of these consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of our assets, liabilities, revenues and expenses, the amounts of charges accrued by us and related disclosure of contingent assets and liabilities. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances. We cannot assure, however, that our estimates, or the assumptions underlying them, will not change over time or otherwise prove inaccurate. For example, our estimates as they relate to anticipated timelines and milestones for our clinical trials or preclinical development may prove to be inaccurate. If this is the case, we may be required to restate our consolidated financial statements, which could, in turn, subject us to securities class action litigation. Defending against such potential litigation relating to a restatement of our consolidated financial statements or otherwise would be expensive and would require significant attention and resources of our management. Moreover, our insurance to cover our obligations with respect to the ultimate resolution of any such litigation may be inadequate. As a result of these factors, any such potential litigation could have a material adverse effect on our financial results, harm our business, and cause our share price to decline.

We do not anticipate paying any cash dividends on our ordinary shares in the foreseeable future.

We have never declared or paid cash dividends on our ordinary shares. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business, and we do not anticipate paying any cash dividends on our ordinary shares in the foreseeable future. In addition, the terms of any future debt agreements may preclude us from paying dividends. As a result, capital appreciation, if any, of our ordinary shares will be our shareholders’ sole source of gain for the foreseeable future.

We may incur significant costs from class action litigation due to share volatility.

Our share price may fluctuate for many reasons, including as a result of public announcements regarding the progress of our development efforts or the development efforts of our collaborators and/or competitors, the addition or departure of our key personnel, variations in our quarterly operating results and changes in market valuations of pharmaceutical and biotechnology companies. Holders of stock whichthat has experienced significant price and trading volatility have occasionally brought securities class action litigation against the companies that issued the stock. If any of our shareholders were to bring a lawsuit of this type against us, even if the lawsuit is without merit, we could incur substantial costs defending the lawsuit. The lawsuit could also divert the time and attention of our management, which could harm our business.

Sales of additional ordinary shares could cause the price of our ordinary shares to decline.

Sales of substantial amounts of our ordinary shares in the public market, or the availability of such shares for sale, by us or others, including the issuance of ordinary shares upon exercise of outstanding options or vesting of outstanding restricted share units, or the perception that such sales could occur, could adversely affect the price of our ordinary shares. Certain of our shareholders have required us, or have the right to require us, to register the sales of their shares under the Securities Act of 1933, as amended, or the Securities Act under agreements between us and such shareholders. For example, in August 2019, we filed a registration statement on Form S-3, which was declared effective on August 14, 2019, to register the resale from time to time by certain of our executive officers, directors and their affiliates of up to approximately 7.1 million ordinary shares.

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If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, our share price and trading volume could decline.

The trading market for our ordinary shares may depend in part on the research and reports that securities or industry analysts publish about us or our business. If too few securities or industry analysts cover our company, the trading price for our ordinary shares would likely be negatively impacted. If one or more of the analysts who cover us downgrade our ordinary shares or publish inaccurate or unfavorable research about our business, our share price would likely decline. If one or more of these analysts cease coverage of our company or fail to publish reports on us regularly, demand for our ordinary shares could decrease, which might cause our share price and trading volume to decline.

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None.

We maintain our U.S. corporate offices and research and development facilities in Cambridge, Massachusetts, where we lease office and laboratory space. In December 2020, we exercised our option to lease an additional 13,126 square feet of the facility and the lease for the additional space is expected to commence on October 1, 2021. The combined space results in a total of approximately 44,000 square feet, which constitutes the entire building.feet.

We lease approximately 90,000 square feet of office and laboratory space in Lexington, Massachusetts, which we use for our research, development and current good manufacturing practice (“cGMP”)cGMP manufacturing.

We also occupy laboratory and office space in Japan. We believe our existing facilities are adequate to meet our current needs.

We are not currently a party to any material legal proceedings.

Not applicable.

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PART II

Market Information

Our ordinary shares are traded on the Nasdaq Global Market under the symbol “WVE”.

Shareholders

As of February 22, 2021,25, 2022, we had 48,997,36860,844,495 ordinary shares outstanding and approximately 12 shareholders of record of our ordinary shares.

Unregistered Sales of Securities

Not applicable.

Issuer Purchases of Equity Securities

None.

Not applicable.

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The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our financial statements and related notes appearing elsewhere in this Annual Report on Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report on Form 10-K, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Annual Report on Form 10-K, our actual results could differ materially from the results described in, or implied by, these forward-looking statements.

Overview

We are a clinical-stage genetic medicines company committed to delivering life-changing treatments for people battling devastating diseases. Using PRISM™, our proprietary discovery and drug development platform that enables the precise design, optimization and production of novel stereopure oligonucleotides, we aspire to develop best-in-class medicines that target the transcriptome to treat genetically defined diseases with a high degree of unmet need.

We are developing oligonucleotides that target ribonucleic acid (“RNA”) and harness existing cellular machinery to reduce the expression of disease-promoting RNA or proteins, restore the production of functional proteins, or modulate protein expression. By intervening at the RNA level, we have the potential to address diseases that have historically been difficult to treat with small molecules or biologics, while retaining the ability to titrate dose, modulate duration of effect, and avoid risk of permanent off-target genetic changes and other challenges associated with DNA editing or gene therapy approaches. Oligonucleotides have additional advantages as a therapeutic class, including the ability to access multiple tissue types and the ability to modulate the frequency of dosing to ensure broad distribution within tissues over time. Oligonucleotides also have well-established manufacturing processes and validated test methods based on decades of improvements, as well as established regulatory, access and reimbursement pathways.

Our approach is based on the scientific insight that the biological machinery necessary to address genetic diseases already exists in human cells and can be controlled with the right tools. We have built a genetic toolkit comprised of multiple therapeutic modalities, including RNase-H mediated silencing, RNAi, splicing, and RNA base editing, all of which leverage learnings and optimizations from our PRISM platform and allow us to design built-for-purpose molecules to optimally address disease biology.  

Our A-to-I RNA base editing oligonucleotides (“AIMers”) represent our newest therapeutic modality. AIMers are designed to correct single base mutations on RNA transcript, thereby avoiding permanent changes to the genome that occur with DNA-targeting approaches. Rather than using an exogenous editing enzyme, AIMers recruit proteins that exist in the body, called ADAR (adenosine deaminases acting on RNA) enzymes, which naturally possess the ability to change an adenine (A) to an inosine (I), which cells read as guanine (G). This approach enables simplified delivery and avoids the risk of irreversible off-target effects with DNA-targeting approaches. AIMers are short in length, fully chemically modified, and use novel chemistry, including proprietary PN backbone modifications and chiral control, which make them distinct from other ADAR-mediated editing approaches.

Our PRISM platform is built on the recognition that a significant opportunity exists to tune the pharmacological properties of oligonucleotide therapeutics by leveraging three key features of these molecules: sequence, chemistry, and stereochemistry. Our unique ability to control stereochemistry, which is a reality of chemically modified oligonucleotides, provides the resolution necessary to optimize pharmacological profiles. PRISM therefore enables us to design stereopure oligonucleotides, which are comprised of molecules with atoms precisely and purposefully arranged in three-dimensional orientations at each linkage. These differ from the mixture-based oligonucleotides currently on the market or in development by others. Additionally, to mitigate pharmacological risks

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and potential manufacturing challenges, our approach focuses on designing short, chemically modified oligonucleotides without the need for complex delivery vehicles.

Our work in developing stereopure oligonucleotides has enabled the continued evolution of PRISM and our drug discovery process of selecting genetically defined targets, identifying a sequence and applying the therapeutic modality we determine is best suited for the disease biology. We use our PRISM platform engine to screen candidates and optimize the pharmacologic profile based on predefined design principles, which reflect a deep understanding of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key pharmacological properties. Through continued exploration of these interactions using iterative analysis of in vitro and in vivo outcomes and machine learning-driven predictive modeling, we also continue to refine our design principles that we deploy across subsequent programs.

In August 2020, we publicly introduced our novel PN backbone chemistry modifications, which have been shown preclinically to increase potency, distribution and durability of effect across various modalities. PN chemistry has been incorporated into all of our current clinical, preclinical and discovery-stage programs.

We have a robust and diverse pipeline of PN-modified, stereopure oligonucleotides, including our clinical silencing and splicing programs, as well as our AIMers. Our lead clinical development programs are designed to treat genetic diseases within the central nervous system (“CNS”), including amyotrophic lateral sclerosis (“ALS”), frontotemporal dementia (“FTD”), Huntington’s disease (“HD”), and muscular dystrophies, including Duchenne muscular dystrophy (“DMD”). These programs include:

With RNA base editing, our initial focus is on using GalNAc-conjugated AIMers to treat hepatic diseases and our lead program is designed to treat alpha-1antitrypsin deficiency (“AATD”). We expect to select an AATD AIMer development candidate and initiate IND-enabling toxicology studies in the third quarter of 2022.

We continue to invest in PRISM to further evolve and apply the expanding capabilities and promise of our unique platform. We have also established and continue to enhance our internal current good manufacturing practices (“cGMP”) manufacturing capabilities to increase control and visibility of our drug substance supply chain, while continuing to innovate oligonucleotide manufacturing.

COVID-19 Business Update

We arecontinue to closely monitoringmonitor developments related to COVID-19, which was declared a pandemic by the World Health Organization on March 11, 2020. In response to this global pandemic, we have concentrated our efforts on the health and safety of our employees and patients, while maintaining business continuity and honoring our commitment to deliver life-changing treatments for people battling devastating diseases.

We implemented business continuity plans in March 2020 designed to address the impact and potential impact of COVID-19 on our operations. Effective March 12, 2020, we implemented measures to mitigate the spread of COVID-19 and contribute to the ongoing public health effort to reduce the spread of the virus. We formed a COVID-19 Response Team to maintain business continuity while safeguarding employee and patient health. We also mandated a work-from-home policy for most employees and set up additional processes to work from home effectively, including measures to bolster our cybersecurity. Since early June 2020, we have been able to increase the number of employees working onsite, as well as expand the amount and type of manufacturing and lab-based activities being conducted onsite.

Our manufacturing operations and lab-basedon-site activities continue with social-distancing and updated protocols for safely accessing and working within our facilities. Asfacilities, including a biopharmaceutical research and development company,mandatory COVID-19 vaccination policy that we are deemed to provide essential services under the “stay at home” advisory that was issued by the Governor of Massachusetts on March 23, 2020.implemented in October 2021. While we continue to conduct R&Dresearch and development activities, including our ongoing clinical trials, the COVID-19 pandemic has impacted, and may continue to impact, certain of our early-stage discovery efforts and clinical trials. We are working with our clinical investigators, R&Dresearch and development vendors, and supply chain vendors to continually assess and take steps to mitigate the potential impact of COVID-19 on our manufacturing operations and R&Dresearch and development activities.

We will continue to closely monitor the COVID-19 situation (along with emerging or future variants of COVID-19) as we evolve our business continuity plans. Given the global economic slowdown and the other risks and uncertainties associated with COVID-19, our business, financial condition, results of operations, and prospects could be materially adversely affected. For additional information, see “Item 1A. Risk Factors” of this Annual Report on Form 10-K.

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Overview

We are a clinical-stage genetic medicines company committed to delivering life-changing treatments for people battling devastating diseases. Using PRISM™, our proprietary discovery and drug development platform that enables the precise design, optimization and production of novel stereopure oligonucleotides, we aspire to develop best in class medicines for genetically defined diseases with a high degree of unmet need.

We are developing oligonucleotides that target ribonucleic acid (“RNA”) to either reduce the expression of disease-promoting proteins or transform the production of dysfunctional mutant proteins into the production of functional proteins. By intervening at the RNA level, we have the potential to address diseases that have historically been difficult to treat with small molecules or biologics, while retaining the ability to titrate dose and avoid permanent off-target genetic changes and other challenges associated with DNA editing or gene therapy approaches. The mechanisms that we are currently using to target RNA with our oligonucleotides include silencing, splicing, and ADAR (adenosine deaminases acting on RNA)-mediated RNA editing (“ADAR editing”). Oligonucleotides have additional advantages as a therapeutic class including the ability to access multiple tissue types and the ability to modulate the frequency of dosing to ensure broad distribution within tissues over time. Oligonucleotides also have well-established manufacturing processes and validated test methods based on decades of improvements.

The oligonucleotides we are developing with PRISM are stereopure and differ from the mixture-based oligonucleotides currently on the market or in development by others. A stereopure oligonucleotide is comprised of molecules with atoms precisely arranged in three-dimensional orientations at each linkage. Based on our preclinical studies, we believe that controlling the stereochemistry of each backbone position will allow us to optimize the pharmacological profile of our oligonucleotides by maximizing the potential therapeutic benefit while minimizing the potential for side effects and safety risks. To further mitigate pharmacological risks and potential manufacturing challenges, our approach focuses on designing oligonucleotides without the need for delivery vehicles. Through our work in developing stereopure oligonucleotides, we have created and continue to evolve PRISM, our proprietary discovery and drug development platform.

PRISM enables us to target genetically defined diseases with stereopure oligonucleotides across multiple therapeutic modalities. PRISM combines our unique ability to construct stereopure oligonucleotides with a deep understanding of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key pharmacological properties. By exploring these interactions through iterative analysis of in vitro and in vivo outcomes and machine learning-driven predictive modeling, we continue to define design principles that we deploy across programs to rapidly develop and manufacture clinical candidates that meet pre-defined product profiles. In August 2020, we introduced our novel PN backbone chemistry modifications, which were discovered through PRISM and have been shown preclinically to increase potency, tissue exposure and durability across various modalities.

Our lead clinical development programs are focused on genetic diseases within neurology. Our first stereopure therapeutic candidates in development, WVE-120101 and WVE-120102, are designed to selectively target mutant huntingtin (“mHTT”) and spare wild-type, or healthy, huntingtin (“wtHTT”) for the treatment of Huntington’s disease (“HD”). WVE-120101 and WVE-120102 are currently being studied in two Phase 1b/2a clinical trials, PRECISION-HD1 and PRECISION-HD2, and we expect to deliver data from both trials at the end of the first quarter of 2021. We also expect to initiate dosing in three new clinical trials with compounds containing our novel PN backbone chemistry modifications in 2021. These new programs include WVE-003, our mHTT SNP3 program for the treatment of HD, WVE-004, our C9orf72 program for the treatment of amyotrophic lateral sclerosis (“ALS”) and frontotemporal dementia (“FTD”), and WVE-N531, our Exon 53 program for the treatment of Duchenne muscular dystrophy (“DMD”). We continue to advance our ATXN3 program in SCA3. We are also pursuing additional programs in disorders of the central nervous system (“CNS”), including Alzheimer’s disease, Parkinson’s disease, and others, in collaboration with Takeda Pharmaceutical Company Limited (“Takeda”). In addition to neurology, our pipeline includes programs in hepatic diseases, including alpha-1 antitrypsin disease (“AATD”), and ophthalmologic disorders, specifically inherited retinal diseases. We continue to invest in PRISM to continue to evolve and apply the expanding capabilities and promise of our unique platform. We have also established and continue to enhance our internal current good manufacturing practices (“cGMP”) manufacturing capabilities to increase control and visibility of our drug substance supply chain, while continuing to innovate oligonucleotide manufacturing.

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Financial Operations Overview

We have never been profitable, and since our inception, we have incurred significant operating losses. Our net loss was $122.2 million in 2021 and $149.9 million in 2020 and $193.6 million in 2019.2020. As of December 31, 20202021 and 2019,2020, we had an accumulated deficit of $683.3$805.5 million and $533.4$683.3 million, respectively. We expect to incur significant expenses and operating losses for the foreseeable future.

Revenue

We have not generated any product revenue since our inception and do not expect to generate any revenue from the sale of products for the foreseeable future. Our revenue during the years ended December 31, 20202021 and 20192020 represented revenue earned under our two revenue-generating collaboration agreements: the Pfizer Collaboration Agreement (as defined in Note 5 in the notes to the consolidated financial statements appearing elsewhere in this Annual Report on Form 10-K (“Note 5”)), which was entered into in

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May 2016 and ended by its original terms in May 2020, and the Takeda Collaboration Agreement (as defined in Note 5), which became effective in April 2018.

Operating Expenses

Our operating expenses since inception have consisted primarily of research and development expenses and general and administrative expenses.

Research and Development Expenses

Research and development expenses consist primarily of costs incurred for our research activities, including our discovery efforts, and the development of our product candidates, which include: