UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 20202021

OR

Commission File Number 001-39247

IMARA INC.

(Exact name of Registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 206-2020

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-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 voting and non-voting common equity held by non-affiliates of the Registrant, based on the closing price of the shares of common stock on the Nasdaq Global Select Market on June 30, 20202021 was $190,476,799.$87,931,922.

The number of shares of Registrant’s Common Stock outstanding as of March 1, 20212022 was 17,575,248.26,287,264.

Table of Contents

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS AND INDUSTRY DATA

This Annual Report on Form 10-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, that involve substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this Annual Report on Form 10-K, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans and objectives of management, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “would,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

The forward-looking statements in this Annual Report on Form 10-K include, among other things, statements about:

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Annual Report on Form 10-K, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we

make. We have included important factors in the cautionary statements included in this Annual Report on Form 10-K, particularly in the "Risk Factors" section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make.  

You should read this Annual Report on Form 10-K and the documents that we have filed as exhibits to Annual Report on Form 10-K completely and with the understanding that our actual future results may be materially different from what we expect. The forward-looking statements contained in this Annual Report on Form 10-K are made as of the date of this Annual Report on Form 10-K, and we do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law.

This Annual Report on Form 10-K includes statistical and other industry and market data that we obtained from industry publications and research, surveys and studies conducted by third parties as well as our own estimates of potential market opportunities. All of the market data used in this Annual Report on Form 10-K involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such data. Industry publications and third-party research, surveys and studies generally indicate that their information has been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. Our estimates of the potential market opportunities for our product candidates include several key assumptions based on our industry knowledge, industry publications, third-party research and other surveys, which may be based on a small sample size and may fail to accurately reflect market opportunities. While we believe that our internal assumptions are reasonable, no independent source has verified such assumptions.

RISK FACTOR SUMMARY

Our business is subject to a number of risks that if realized could materially affect our business, financial condition, results of operations, cash flows and access to liquidity. These risks are discussed more fully in Part I, Item 1A. “Risk Factors” of this Annual Report on Form 10-K. Our principal risks include the following:

PARTPART I

Item 1. Business.

Overview

We are a clinical-stage biopharmaceutical company dedicated to developing and commercializing novel therapeutics to treat patients suffering from rare inherited genetic disorders of hemoglobin, known as hemoglobinopathies.hemoglobinopathies, and other serious diseases. Our pipeline is built on the differentiated therapeutic potential of our initiallead product candidate, IMR-687,tovinontrine (IMR-687), which is an oral, once-a-day, potentially disease-modifying treatment for sickle cell disease, or SCD, and β-thalassemia. IMR-687 is a highly selective, potent small molecule inhibitor of phosphodiesterase-9, or PDE9, that has a multimodal mechanism of action that acts primarily on red blood cells, or RBCs, and has the potential to act on white blood cells, or WBCs, adhesion mediators and other cell types that are implicatedPDE9.  Tovinontrine is currently in these disorders. We recently completed a Phase 2a clinical trial of IMR-687 in adult patients with SCD and are currently conducting an open label extension, or OLE, clinical trial, which allows patients from the Phase 2a clinical trial to continue into a long-term four-year trial to test safety and measure tolerability of IMR-687.  In the second quarter of 2020, we initiated a Phase 2b clinical trialdevelopment for the treatment of patients withsickle cell disease, or SCD, and a Phase 2b clinical trial for the treatment of patients with β-thalassemia. We are currently enrolling patients in each Phase 2b clinical trialβ-thalassemia and we expect to report interim data from eachbegin clinical development of these trials in the second half of 2021. We continue to evaluate the impact of the COVID-19 pandemic on these Phase 2b clinical trials, and therefore, our estimated timelines for these clinical trials could be delayed. Our goal is to leverage IMR-687’s differentiated mechanism of action, its ease of administration and stable drug properties to potentially serve a broad range of patients suffering from hemoglobinopathies around the world, including those in underserved regions. In addition, we recently completed preclinical research of IMR-687tovinontrine in heart failure with preserved ejection fraction, or HFpEF, andin the second quarter of 2022.  We are developing a Phasealso advancing IMR-261, an oral, clinic-ready activator of nuclear factor erythroid 2–related factor 2, protocol to support potential future clinical development of IMR-687 in this indication.or Nrf2.  

Disease Areas

Hemoglobinopathies

Hemoglobinopathies are a diverse range of rare inherited genetic disorders in which there is abnormal production or absencedecreased production of hemoglobin, the iron-containing protein in red blood cells, or RBCs, responsible for transporting oxygen in the blood. Hemoglobinopathies can be broadly categorized into two groups. The first group, of hemoglobinopathies, which includes SCD, results from structural abnormalities in hemoglobin that cause RBCs to become inflexible and elongated (sickle-shaped), ultimately blocking blood flow to organs, which can lead to vaso-occlusive crises, or VOCs. SCD is characterized by debilitating pain, progressive multi-organ damage and early death. The global prevalence of SCD is estimated to be approximately 4.4 million patients, including approximately 100,000 patients in the United States and 134,000 patients in the European Union.

The second group of hemoglobinopathies, which includes β-thalassemia, results from decreased or absent production of hemoglobin thereby producingor ineffective erythropoiesis (RBC production), leading to fewer, smaller, paler RBCs that do not deliver adequate oxygen to vital tissues.and chronic anemia. β-thalassemia is often grouped into two subsets: patients who arewith non-transfusion dependent thalassemia, or NTDT, orand patients who arewith transfusion dependent thalassemia, or TDT. If left untreated, β-thalassemia causes severe anemia, splenomegaly, skeletal abnormalities, leg ulcers, iron overload, and organ failure, andoften leading to early death. Both groups of hemoglobinopathies share similar pathophysiology and have limited treatment options, which results in a significant unmet medical need for patients. The global prevalence of SCD and β-thalassemia areis estimated to be approximately 4.4 million and 288,000 patients, respectively. with the total combined prevalence in the United States and the European Union estimated to be approximately 19,000 patients.

SCD and β-thalassemia are both designated as rare diseases in the United States and the European Union. For SCD, prevalence

Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction, or HFpEF, also known as diastolic heart failure, is typically caused by abnormalities of cardiac filling, which leads to symptoms such as shortness of breath, exercise intolerance and fluid retention. Characteristics of HFpEF are heterogeneous, but commonly include ventricular hypertrophy, diastolic dysfunction, endothelial dysfunction, insulin resistance, and inflammation. Comorbidities, such as hypertension, anemia, chronic kidney disease, diabetes, and obesity, are also common in HFpEF and are thought to contribute to its development.  HFpEF accounts for approximately half of all cases of heart failure and has become the predominant form of heart failure over time.   Prevalence in the United States is estimated to be approximately 100,0003-4 million patients.  In contrast to heart failure with reduced ejection fraction, or HFrEF, there are relatively few treatment options to improve symptoms and outcomes for patients inand there are currently only two FDA-approved products (Entresto and Jardiance) for the United States and 134,000 patients in the European Union. For β-thalassemia, total combined prevalence in the United States and the European Union is estimated to be approximately 19,000 patients.treatment of HFpEF.

Product Candidates

Tovinontrine (IMR-687)

Our productlead candidate, IMR-687,tovinontrine, is a highly selective and potent small molecule inhibitor of PDE9. PDE9 selectively degrades cyclic guanosine monophosphate, or cyclic GMP,cGMP, an active signaling molecule that plays an important role in vascular biology. Lower levels of cyclic GMPcGMP are found in patients with SCD and β-thalassemia and are associated with reduced blood flow, increased inflammation, greater cell adhesion and reduced nitric oxide mediated vasodilation. Blocking PDE9 acts to increase cyclic GMPcGMP levels, which is associated with several benefits including the potential reactivation of fetal hemoglobin, or HbF, a natural hemoglobin produced during fetal development.development, lower white blood cell, or WBC, activation and reduced adhesion across various cell types. Increased levels of HbF in RBCs have been demonstrated to improve symptomology and substantially lower disease burden in both patients with SCD and patients with β-thalassemia. Increasing cyclic GMP is associatedβ-thalassemia and, along with lowerreduced WBC activationadhesion and platelet aggregation, may result in fewer VOCs for SCD patients.

In addition, levels of cGMP are often reduced adhesion across various cell types, both of which also contribute to SCD. Finally, activation ofin patients with heart failure. Augmenting cGMP through the nitric oxide-cyclic GMPnatriuretic peptide-cGMP pathway has been shown to induce red cell maturationmediate cardioprotective effects that lead to reduced heart failure disease progression and production, which are particularly relevant in treating β-thalassemia. fewer cardiac events.

We believe IMR-687 has several differentiating features that make ittovinontrine may have advantages over other therapies, including having a multimodal approach and being an optimal therapeutic for SCD and β-thalassemia, as supported by our preclinical data:

Managing hemoglobinopathies and their various clinical manifestations is complex and patients have had limited treatment options. In November 2019, the U.S. Food and Drug Administration, or FDA, approved Oxbryta™ (voxelotor) and Adakveo^® (crizanlizumab) for the treatment of SCD which are important milestones for patients with SCD as previously approved therapies for SCD all have significant limitations, including safety concerns, complex dosing regimens, variable response rates and potential adverse effects from long term use. We believe that IMR-687’s differentiated mechanism of action that seeks to increase HbF in patients with SCD, and the association between increases in HbF and reductions in disease risk, have the potential to provide IMR-687, if approved, with competitive advantages over Oxbryta, where the correlation between increases in hemoglobin and disease risk is being tested in a post-approval confirmatory trial, and Adakveo, which is administered intravenously and does not target RBC sickling.Program

There are no currently approved oral therapies for β-thalassemia; however, in November 2019, the FDA approved REBLOZYL™ (luspatercept-aamt), which is dosed subcutaneously, for the treatment of anemia in adult patients with β-thalassemia who require regular RBC transfusions. Blood transfusions are used to treat both SCD and β-thalassemia, but are suboptimal due to limited patient access and potential serious complications that include iron overload, adverse immune response and transmission of transfusion-associated infections. Allogeneic hematopoietic stem cell transplant, or HSCT, is a potentially curative treatment for both disorders, but is rarely used due to the difficulty in finding a matched donor and an approximately 5% mortality rate. More recent approaches to treating both disorders are emerging, such as gene therapy and gene editing, with promising early clinical data being observed in each. These approaches, however, are complex, costly, difficult to administer and potentially only suitable for a limited subset of patients.

Based on promising preclinical data and data from a Phase 1 clinical trial of IMR-687 in healthy volunteers, in 2018 we initiated our Phase 2a randomized, double-blinded, placebo-controlled clinical trial of IMR-687 in adult patients with SCD. The goals of this trial were to evaluate the safety, tolerability, pharmacokinetics, or PK, exploratory pharmacodynamics, or PD, and clinical outcomes of IMR-687 administered once daily for 16 or 24 weeks in two populations of patients with SCD: one on monotherapy IMR-687 and one on background hydroxyurea, or HU, in combination with IMR-687 to test drug-drug interaction.

In January 2021, we reported final results from the Phase 2a clinical trial. The results showed a lower rate of vaso-occlusive crises/sickle cell-related pain crises, or VOCs/SCPCs, as part of the safety analysis, and VOC-related hospitalizations in specified monotherapy IMR-687 treated patients, as compared to placebo.  Changes in HbF and F-cells varied across patient populations in the clinical trial.  The results further showed IMR-687 was well tolerated as a monotherapy and in combination with HU.

We are alsocurrently conducting an OLE clinical trial, which allows patients from the Phase 2a trial to continue into a long-term, four-year trial to evaluate safety and tolerability of IMR-687. A review of approximately 12 patients with evaluable PD biomarker data for at least four months of treatment on the OLE clinical trial as of December 31, 2020, demonstrated increases in both HbF and F-cells and minimal changes in total hemoglobin.

In the second quarter of 2020, we initiated aArdent Phase 2b clinical trial of IMR-687tovinontrine, a randomized, double-blind, placebo-controlled trial in approximately 115 adult patients with SCD and a Phase 2bSCD.  We have completed enrollment in the Ardent clinical trial of IMR-687 in adult patients with ß-thalassemia. We are currently enrolling patients in each trial and expect to report interim data from eachthis trial in the first week of these trialsApril 2022 and final data in the second half of 2021. Based on2022.  In November 2021, we made the supportive safety and PK datadecision to change the primary endpoint of the Ardent trial to annualized rate of VOCs following a written recommendation from the Phase 2a interim analyses, we designedFDA.  HbF response, which was previously the Phase 2b clinical trialsprimary endpoint, will continue to evaluate higher doses, longer treatment periods, and additional clinical endpointsbe evaluated as compared to the Phase 2a clinical trial.a key secondary endpoint.

In addition to our clinical programs with IMR-687 in patients with SCD and β-thalassemia, in the second quarter The Ardent trial follows completion of 2020, we commenced preclinical development of IMR-687 in HFpEF.  Published literature suggests that the inhibition of PDE9, and resulting increases in cyclic GMP through natriuretic peptide modulation, can serve as an attractive target for the prevention and treatment of vascular disease, including HFpEF.  An exploratory analysis co-led by Vanderbilt University Medical Center, or VUMC, on data from the second interim analysis from our Phase 2a clinical trial of IMR-687tovinontrine in SCD, which demonstrated a well-tolerated safety profile for tovinontrine and potential benefits from tovinontrine with respect to VOCs.  Changes in SCD-related biomarkers were variable.  

We are also conducting a long-term open label extension, or OLE, clinical trial of tovinontrine, which is comprised of patients who completed our Phase 2a clinical trial of tovinontrine.  Data from the OLE trial presented at the American Society of Hematology (ASH) Annual Meeting in December 2021 demonstrated a well-tolerated safety profile for tovinontrine, potential benefits from tovinontrine with respect to VOCs and improvements in certain SCD-related biomarkers, including HbF and F-cells, through 12 months of IMR-687treatment on the OLE trial.  

In the second quarter of 2022, we expect to reduceinitiate a new, long-term OLE trial of tovinontrine for patients who complete the Ardent Phase 2b clinical trial in SCD.  In addition to patients from the Ardent trial, we expect patients from the ongoing Phase 2a OLE trial to roll over into this new OLE trial, resulting in one OLE trial with patients from both the Phase 2a clinical trial and the Ardent Phase 2b clinical trial.

ß-thalassemia Program

We are also conducting the Forte Phase 2b clinical trial of tovinontrine, a randomized, double-blind, placebo-controlled trial in approximately 120 TDT and NTDT patients with ß-thalassemia.  In November 2021, we presented data from a pre-specified interim analysis from the Forte trial in TDT patients.  The interim analysis data demonstrated a well-tolerated safety profile for tovinontrine and a trend for reduced transfusion burden in the higher dose cohort.  We expect to report additional interim data for TDT and NTDT patients from the Forte trial in the first week of April 2022 and data from the final analysis of the Forte clinical trial in the second half of 2022.

HFpEF Program

In the second quarter of 2022, we expect to dose the first patient in the SP₉IN Phase 2 clinical trial of tovinontrine in HFpEF.  The SP₉IN trial will be a randomized, placebo-controlled trial of approximately 170 patients 45 years of age or older with enriched PDE9 expression and persistent symptoms of HFpEF.  The primary endpoint of the trial will be the change in N-terminal pro-B-typepro b-type natriuretic peptide, or NT-proBNP, levels.

IMR-261

We have commenced research activities for IMR-261 (formerly CXA-10), an oral, clinical-ready activator of Nrf2.  In pre-clinical models of SCD, IMR-261 was observed to activate expression of HbF and reduce VOCs. Furthermore, in a well-established biomarkerpreclinical model of cardiovascular riskß-thalassemia, IMR-261 was observed to increase hemoglobin and enhance RBC maturation.  We have initiated work on drug product manufacturing for IMR-261 as we explore potential clinical development paths in patients with SCD.  In April 2020, we entered into an agreement with the Necker Institute of Paris, Francehemoglobinopathies, iron disorders and potentially other areas.

Prior to conduct preclinical studies with IMR-687its acquisition by us, IMR-261 was evaluated by Complexa, Inc. in HFpEF. The preclinical data from three established mouse models for HFpEF suggest potential benefits of IMR-687 across several relevant cardiac biomarkers. We are collaborating with VUMC and have engaged additional key opinion leaders in heart failure, with the aim of developing a Phase 2 protocol to supportclinical trials in focal segmental glomerulosclerosis, or FSGS, and pulmonary arterial hypertension, or PAH, and independent medical literature suggests potential future clinical developmentin a broad array of IMR-687 in this indication.RBC diseases, including disorders of hemoglobin, and iron overload diseases. 

Our Pipeline

We are advancing a pipeline of therapeutic programs to address diseases with significant unmet medical need. The following chart summarizes key information about our programs:

Our Strategy

Our goal is to become a leading biopharmaceutical company focused on the development and commercialization of novel therapies for the treatment of hemoglobinopathies.therapies. To achieve this, we are focused on the following key strategies:

Sickle Cell Disease Overview

SCD is the most common type of inherited hemoglobinopathy. SCD is characterized by debilitating pain, progressive multi-organ damage and early death. Beginning early in life, patients suffer from blocked blood flow to tissues, known as vaso-occlusion, destruction of RBCs, known as hemolysis, and inadequate oxygen delivery, or hypoxia. The most common complication of SCD is pain, often a consequence of VOCs. A VOC occurs when circulation is obstructed by sickled RBCs, causing tissue damage to the organ and resultant pain. The outcomes of these events begin presenting early in childhood and quickly lead to heart and lung complications, renal disfunction, prolonged refractory penile erection (known as priapism), spleen enlargement and failure, stroke, retinopathy and mental and physical disabilities. Given the constellation of these comorbidities, patients with SCD have a diminished quality of life and on average have a significantly shorter lifespan than normal healthy adults, sometimes up to 20 to 30 years shorter.

SCD is caused by a single mutation in the gene that expresses the beta globin subunit of hemoglobin. Hemoglobin in RBCs consists of two beta globin and two alpha globin subunits. Hemoglobin’s primary function is to transport oxygen from the lungs to tissues throughout the body and return carbon dioxide back to the lungs. In oxygen rich environments, like the lungs, hemoglobin has a high affinity for oxygen and binds to it rapidly. In lower oxygen surroundings, like peripheral tissues, hemoglobin has a low affinity for oxygen and releases it quickly. The beta globin subunit mutation in SCD leads to the production of abnormal hemoglobin known as sickle hemoglobin, or HbS. HbS is comprised of two mutant beta globin and two normal alpha globin subunits. In reduced oxygen settings, HbS permits hydrophobic associations between the mutated beta globin subunits and the normal alpha subunits. This causes the oxygen deficient hemoglobin units to assemble into long chains in an event known as polymerization. These long, fixed chains of hemoglobin distort the flexible disc-like RBC into an inflexible crescent or “sickled” shape. Although the sickled RBC may convert back into a regular RBC in oxygen rich environments, it will return to its sickled form in lower oxygen environments and ultimately may be permanently sickled and/or be destroyed.

There are several genetic variations of SCD, including:

Although patients with SCD often present a spectrum of symptoms that can vary over time, patients are often grouped by their predominant symptomology: those that present with hemolytic anemia, which is largely driven by sickled RBCs, and those that present with painful VOCs, where RBCs, WBCs and other cell types play a role.

The Role of Fetal Hemoglobin on RBC Pathophysiology and SCD

One way to prevent the polymerization of HbS that results in sickled RBCs is to enhance the overall affinity of hemoglobin for oxygen, which reduces sickling in low oxygen environments and ameliorates pathophysiology of the disease. A promising approach to enhance hemoglobin-oxygen affinity is to reactivate production of inactive HbF, which we refer to as HbF induction. HbF is a natural hemoglobin that is activated during fetal development and is designed to give the growing

fetus better access to oxygen from the maternal bloodstream. HbF has higher affinity for oxygen and ceases production approximately six months after birth, at which time it is replaced by adult hemoglobin that has lower oxygen affinity. Accordingly, newborns with SCD do not experience RBC sickling andor resulting symptomology in the first four to five months of life. As HbF production declines and mutated HbS is produced in its place, SCD clinical manifestations begin to rapidly emerge. Some children with SCD mature into adulthood with persistence of HbF, otherwise known as hereditary persistence of HbF, and this reduces the long-term clinical manifestations of SCD. In some cases, these patients are essentially asymptomatic. We believe that the protective aspects of naturally occurring HbF supports the development of therapies that induce HbF as a means to treat SCD.

The image below depicts how RBCs can change shape in low oxygen environments. In healthy individuals, there is no change to the hemoglobin organization or RBC structure. In SCD, hydrophobic interactions with the hemoglobin subunits lead to polymerization and cause RBC distortion. In cells with reactivated HbF, polymerization is avoided because HbF reduces the ability of mutated hemoglobin to polymerize.

Reactivation of HbF occurs in immature RBCs, known as erythroblasts and reticulocytes. These cells are found in the bone marrow and have the cellular machinery to produce HbF. Once HbF is induced in nascent RBCs, they eventually grow into mature RBCs that contain HbF. Mature RBCs that are already in circulation are not viable targets for HbF induction because they do not contain DNA. Over time, these mature RBCs without HbF die out and are replaced by newly mature RBCs that contain HbF, further increasing the population of HbF containing RBCs. This time course can be up to 120 days, which is the lifespan of a normal RBC, or substantially shorter, as sickled RBCs live for only eight to 40 days. Therapies that increase HbF must focus on immature RBCs to ensure HbF is increasingly part of the mature and circulating RBC population.

Measuring the reactivation of HbF is accomplished in two interrelated ways. The first assay confirms if an RBC contains HbF, in which case it is known as an F-cell. We believe that measurements of the percentage of F-cells relative to total RBCs, which we refer to as %F-cells, establish whether a therapy is reactivating HbF production. The second assay quantifies the amount of HbF across RBCs, expressed as a percentage of total hemoglobin, or HbF%. Increasing HbF% is key to addressing SCD disease pathology and ultimately drives the improved hemoglobin-oxygen affinity. As illustrated in the graphic below, which is based on data from 242 pediatric patients with SCD across various genotypes, the relationship between %F-cells and HbF% is exponentially correlated in that linear increases in %F-cells yield multi-fold increases in HbF%.

Relationship Between %F-cells and HbF%

While %F-cells increases are important measurements, absolute increases in HbF% ultimately drive reduction in disease risk. We commissioned a third-party to perform aA systematic literature review and series of quantitative meta-analyses to identify evidence for clinical outcomes associated with HbF% in patients with SCD. Statisticallyrevealed statistically significant associations between HbF%increases in HbF and clinical outcomes in SCD were found for the following:including mortality, stroke, acute chest syndrome, pain, blood transfusion, retinopathy and splenomegaly. The figure below shows how absolute increases in HbF% are associated with reduced disease risk across several of these parameters.

Association Between Increases in HbF% and Disease Risk

The Role of Other Cell Types in SCD

While HbF induction focuses primarily on the RBC aspect of SCD pathophysiology, non-RBC factors also play an important role in SCD. Several other cell types contribute to SCD, including WBCs, endothelial cells and platelets. Dysfunction of these cells, their inter-relationship and resulting downstream inflammatory processes contribute to numerous acute symptoms in SCD patients, such as painful VOCs and multi-organ damage. Third-party clinical data suggest that elevated WBCs are a predictor of increased risk of early death in patients with SCD. Furthermore, in patients with SCD, WBCs are activated and express higher levels of cell surface markers associated with adhesion, such as CD11a, CD11b and CD18. WBCs also interact with sickled RBCs and endothelial cells causing both cell aggregation and adhesion within the blood vessel. As a result, endothelial cells are damaged and secrete inflammatory signals that can ultimately lead to organ

damage. Platelets exacerbate this inflammatory cascade by releasing cell signaling molecules known as cytokines and further

contribute to the cellular blockage in blood vessels that causes VOCs and clinical pathology. The following image describes the role of each of these cells and how they may be implicated in SCD.

VOCs.

The Role of Adhesion Mediators in SCD

In addition to specific cell types playing a role in SCD, adhesion mediators cause RBCs, WBCs, endothelial cells and platelets to stick to one another. These adhesion mediators, known as cell adhesion molecules include selectins and vascular factors that form a multi-cellular lattice that contributes to blood vessel blockage. Inhibition of different types of adhesion mediators has recently become an approach to ameliorate SCD pathophysiology, which is distinct from approaches that solely target the underlying sickled RBC. Adhesion mediators can also be easily measured and therefore serve as reproducible biomarkers across RBCs, WBCs, endothelial cells and platelets. These include P-selectin, E-selectin, vascular cell adhesion molecule 1, or VCAM-1, and intercellular adhesion molecule 1, or ICAM-1.

Addressable Patient Population

The global incidence of SCD is estimated to be approximately 300,000 births annually, and by 2050, incidence is expected to rise to approximately 400,000 births annually. In the United States, where newborn screening for SCD is mandatory, the estimated prevalence is approximately 100,000 individuals. In the European Union, the estimated prevalence is approximately 134,000 individuals. The global prevalence of SCD is estimated to be approximately 4.4 million patients. SCD is most common among people of African, Middle Eastern and South Asian descent.

Approved and Emerging Modalities and Their Limitations

Approved Treatments

Managing SCD and its various clinical manifestations is complex, and patients have historically had limited options for treatment. In November 2019, the FDA granted accelerated approval for Oxbryta (voxelotor) for the treatment of SCD in adultspatients 12 years of age and childrenolder and its label has subsequently been expanded to include patients four years of age and older. In February 2022, the European Commission approved Oxbryta for the treatment of hemolytic anemia in patients with SCD 12 years of age and older. Oxbryta is an oral therapy taken once daily and is the first approved treatment that directly inhibits sickle hemoglobin polymerization. The accelerated approval of Oxbryta was based on clinically meaningful and statistically significant improvements in hemoglobin levels, accompanied by reductions in red blood cell destruction, known as hemolysis. In November 2019, the FDA also approved Adakveo (crizanlizumab), which has been demonstrated to reduce the frequency of VOCs in adult and pediatric patients aged 16 years and older with SCD. Adakveo received conditional approval in the European Union in October 2020 for the prevention of recurrent VOCs in SCD patients aged 16 years and older.  Adakveo is administered intravenously and binds to P-selectin, which is a cell adhesion protein that plays a central role in the multicellular interactions that can lead to vaso-occlusion.VOCs.

While these two approvals are important milestones for patients with SCD, we believe that there remains a significant unmet need for SCD therapies. Oxbryta was approved by the FDA on an accelerated basis based on improvements in hemoglobin levels as a surrogate endpoint reasonably likely to predict clinical benefit.  Continued approval for this indication may be contingent upon verification and description of the clinical benefit in a confirmatory study which is currently ongoing and is evaluating cerebral blood flow velocity. Adakveo does not treat the underlying cause of SCD and is only available through intravenous administration, not in oral form.

Prior to the approval of Oxbryta and Adakveo for SCD, there were only two FDA-approved drugs in the United States to treat SCD: Hydroxyurea, or HU, and L-glutamine (marketed as Endari).Endari (L-glutamine); and only one approved drug in the European Union:  HU. These therapies have significant limitations in their safety, dosing regimen, efficacy and long-term effects.

HU, an oral chemotherapy that induces HbF and decreases sickling of the RBC, was first approved by the FDA for the treatment of SCD in 1998. In1998 and approved in the seminal trial for HU that led to its approval, patients on average saw increased HbF induction of 3.2% over a two-year treatment period, which resultedEuropean Union in improved clinical outcomes, such as reduction of acute chest syndrome.2007. Despite thesenumerous benefits, HU remains a suboptimal therapy for several reasons:

Due to HU’s various limitations, only approximately 30% and 22% of patients with SCD in the United States and certain countries in Europe, respectively, are treated with HU. Of those patients treated with HU in the United States, approximately 50% discontinue use within six months.

Endari, an oral powder form of L-glutamine, was approved by the FDA in 2017, becoming the first new FDA-approved treatment for SCD in nearly 20 years.2017. L-glutamine is an amino acid precursor to nicotinamide adenine dinucleotide, or NAD, and is thought to reduce the oxidative stress that is present in patients with SCD. In September 2019, Emmaus Life Sciences, Inc. withdrew its marketing application to the European Medicines Agency, or EMA, for Endari.

Blood transfusions are another suboptimal treatment option for patients with SCD. Transfusions can transiently bolster hemoglobin levels by adding functional RBCs but can lead to several complications that include iron overload, adverse immune response and transmission of transfusion-associated infections. Due to the lack of uniform accessibility to blood transfusions, they are not widely employed for the treatment of SCD.Allogeneic hematopoietic stem cell transplant, or HSCT, is available as a potentially curative treatment for SCD and acts by halting sickled RBC production from the affected marrow and replacing it with healthy hematopoietic stem cells from a matched donor. HSCT is rarely used due to the difficulty in finding a matched donor, the potential for infection and an approximately 5% mortality rate. The possibility of increased mortality risk relegates this to a last option, often utilized only in the most severe cases.

Due to the limitations of existing therapies, we believe there remains a critical need to develop new preventative therapies that are easy to access, safe for long-term use and address the multiple aspects of SCD pathology.

Emerging Modalities

There has recently been an increased focus on the development of new treatments for SCD with a spectrum of different approaches, but none address the multifactorial pathology of SCD with an oral once-a-day tablet. These approaches can be broadly categorized as follows:

Anti-Polymerization Agents: Anti-polymerization agents, such as Oxbryta, isare designed to prevent polymerization of hemoglobin and sickling of RBCs by increasing hemoglobin’s affinity for oxygen and maintaining hemoglobin in an oxygenated state. However, approaches that are solely focused on reducing polymerization may not address the complex symptomology of SCD and the clinical impact of Oxbryta on VOCs remains a question.

HbF Inducers:  In additionHbF inducers seek to IMR-687, several other novelreactivate production of HbF inducers are in clinical development.  an effort to enhance hemoglobin-oxygen affinity.  Examples include FTX-6058, under development by Fulcrum Therapeutics, Inc. is in Phase 1 clinical, or Fulcrum, and EPI-01, under development of FTX-6058, a small molecule embryonic ectoderm development inhibitor designed to induce expression of HbF.  by Novo Nordisk A/S, or Novo Nordisk (in collaboration with EpiDestiny, Inc.) is in Phase 1 clinical development of EPI-01, a DNA methyltransferase inhibitor., or EpiDestiny).

PKR Activators:  Pyruvate kinase-R, or PKR, is an enzyme that is involved in the conversion of sugar into energy and is critical for the survival of RBCs. Mutations in PKR cause deficiencies in this process which results in a shortened lifespan for RBCs.  This has led to the hypothesis that PKR activation can overturn this deficiency and may lead to a therapeutic benefit in patients with SCD (and potentially ß-thalassemia).SCD.  Examples include mitapivat (AG-348), under development by Agios Pharmaceuticals, Inc. is developing mitapivat (AG-348), or Agios, and etavopivat (FT-4202), which is in Phase 1/2 clinicalunder development andby Forma Therapeutics, Inc. is developing FT-4202, which is in Phase 3 clinical development.  , or Forma.  

Selectin Inhibitors: Pan selectin and specific P-selectin inhibitors, such as Adakveo, are designed to reduce adhesion of WBCs to the endothelial cell wall and reduce VOCs; however, selectin inhibitors do not ultimately prevent the sickling of RBCs in SCD. Furthermore, Adakveo requires lengthy infusion treatments every three to four weeks. Global Blood Therapeutics, Inc.Inc, or GBT, is also developing inclacumab, a specific P-selectin inhibitor that was previously under development for non-SCD indications.  In preclinical studies, inclacumab demonstrated longer duration of exposure and greater inhibition of platelet-leukocyte aggregation as compared to Adakveo, which may create the potential for quarterly dosing, but inclacumab has yet to be tested in SCD patients (although Global Blood Therapeutics has reported that a Phase 3 clinical trial is planned for 2021).  

Gene Therapy/Editing: Gene-based therapy is an innovative and potentially curative approach to SCD treatment. Like HSCT, gene therapy for SCD involves several pre-treatment steps that can include chemotherapy, which carry significant standalone risks. Recent data from a gene therapy trial indicated that chemotherapeutic pre-treatment resulted in a patient with SCD developing myelodysplastic syndrome, where the blood-forming cells in the bone marrow become abnormal. bluebird bio, Inc., or bluebird, and Aruvant Sciences, Inc., or Aruvant, are each developing gene therapies which aim to deliver a functional copy of the human beta-globin gene (LentiGlobin, which is in Phase 3 clinical development, and ARU-1801, which is in Phase 2 clinical development, respectively).gene.  Gene editing, including CRISPR-Cas9, is an alternative approach to gene modification that has recently advanced in clinical development. Examples of gene editing approaches include CTX-001, currently in Phase 2 clinical development by CRISPR Therapeutics AG, or CRISPR (in collaboration with Vertex Pharmaceuticals Incorporated), BIVV-003, currently in Phase 1/2 clinical development by Sangamo Therapeutics, Inc. (in collaboration with Sanofi), and OTQ923, currently in Phase 1/2 clinical development by Intellia Therapeutics, Inc. (in collaboration with Novartis)Incorporated, or Vertex).  Numerous questions remain with respect to the gene editing approach, including off-target mutagenesis and the ultimate potential reach of such therapeutics. More studies are needed to establish durability and safety of these potential treatments.

The Role of Phosphodiesterase-9 in SCDApproved and Emerging Modalities and Their Limitations

IMR-687 is being developed to inhibit PDE9. PDE9 decreases cyclic GMP, an active signaling molecule that plays an important role in vascular biology. Lower levels of cyclic GMP, as found in patients withApproved Treatments

Managing SCD are associated with reduced blood flow, increased inflammation, greater cell adhesion and reduced nitric oxide mediated vasodilation. The figure below illustrates the role of PDE9 inhibition and its potential benefits on SCD pathophysiology. Nitric oxide, a chemical that supports blood vessel health, drives increases in a broadly expressed enzyme, soluble guanyl cyclase, or sGC, which drivesvarious clinical manifestations is complex, and patients have historically had limited options for treatment. In November 2019, the conversion of Guanosine-5’-triphosphate, or GTP, into cyclic GMP. Cyclic GMP levels are decreased by the PDE9 enzyme, which actively converts cyclic GMP to GMP. Increasing cyclic GMP by inhibiting PDE9 has several potential advantageous downstream impacts, including to increase HbF, reduce cell adhesion, decrease WBC activation and ultimately increase nitric oxide levels.

Novel cyclic GMP Degrader: PDE9 belongs to a family of 11 cyclic nucleotide phosphodiesterases, or PDEs. In general, PDEs degrade both cyclic GMP and cyclic adenosine monophosphate, or cAMP. However, PDE9 solely degrades cyclic GMP, has the highest affinityFDA granted accelerated approval for cyclic GMP of all PDEs, and does not degrade cAMP. Inhibiting PDE9 offers a novel way to increase cyclic GMP levels by limiting cyclic GMP degradation. We believe that other approaches that increase cyclic GMP levels without addressing its degradation, such as HU, are unlikely to confer persistent and robust increases in cyclic GMP. Conversely, preventing degradation of cyclic GMP by targeting PDE9 may enable long-term benefits that include sustained HbF induction, reduced activation of WBCs, positive effects on other cell types and reduced cell adhesion.

High Expression in SCD Cells of Interest: PDE9 is highly expressed in cells of interest in SCD, specifically reticulocytes, which are an important cell type for HbF induction. Furthermore, PDE9 has high expression in WBCs and in areas where RBCs are formed. A potential drawback of inhibiting PDE9Oxbryta (voxelotor) for the treatment of SCD is that PDE9 is also highly expressed in patients 12 years of age and older and its label has subsequently been expanded to include patients four years of age and older. In February 2022, the brain, which in part explains why PDE9 inhibitors have been extensively studied in neurodegenerative diseases. While several PDE9 inhibitors have been shown to be well-tolerated in adults, preclinical data suggests that brain penetrant PDE9 inhibition causes mice to have changes in fear response, which may reflect memory impairment. This could be concerning in pediatric patients with SCD who continue to have ongoing brain development. Thus, any PDE9 inhibitor broadly targeting SCD should minimally cross the blood-brain barrier.

Multimodal Method of Action: In preclinical studies, PDE9 inhibitors have been shown to increase cyclic GMP concentrations, induce HbF and F-cells, reduce WBC activation and adhesion across other cell types and modulate adhesion mediators. A brain penetrant PDE9 inhibitor developed by Bayer known as BAY73-6691, which was originally developedEuropean Commission approved Oxbryta for the treatment of neurodegenerative diseases,hemolytic anemia in patients with SCD 12 years of age and older. Oxbryta is an oral therapy taken once daily and is the first approved treatment that directly inhibits sickle hemoglobin polymerization. In November 2019, the FDA also approved Adakveo (crizanlizumab), which has been demonstrated to reduce the frequency of VOCs in adult and pediatric patients aged 16 years and older with SCD. Adakveo received conditional approval in the European Union in October 2020 for the prevention of recurrent VOCs in SCD patients aged 16 years and older.  Adakveo is administered intravenously and binds to P-selectin, which is a cell adhesion protein that plays a central role in the multicellular interactions that can lead to VOCs.

While these approvals are important milestones for patients with SCD, we believe that there remains a significant unmet need for SCD therapies. Oxbryta was observedapproved by the FDA on an accelerated basis based on improvements in hemoglobin levels as a surrogate endpoint reasonably likely to increase cyclic GMPpredict clinical benefit.  Continued approval for this indication may be contingent upon verification and HbF transcriptiondescription of the clinical benefit in a representative human cell lineconfirmatory study which is currently ongoing and is evaluating cerebral blood flow velocity. Adakveo does not treat the underlying cause of SCD and is only available through intravenous administration, not in oral form.

Prior to the approval of Oxbryta and Adakveo for SCD. Furthermore, BAY73-6691SCD, there were only two FDA-approved drugs in the United States to treat SCD: Hydroxyurea, or HU, and Endari (L-glutamine); and only one approved drug in the European Union:  HU. These therapies have significant limitations in their safety, dosing regimen, efficacy and long-term effects.

HU, an oral chemotherapy that induces HbF and decreases sickling of the RBC, was observedfirst approved by the FDA for the treatment of SCD in 1998 and approved in the European Union in 2007. Despite numerous benefits, HU remains a suboptimal therapy for several reasons:

Endari, an oral powder form of L-glutamine, was approved by the FDA in 2017. L-glutamine is an amino acid precursor to nicotinamide adenine dinucleotide, or NAD, and is thought to reduce WBC activation and adhesion to endothelial cells in patient-derived WBCs, however development was subsequently discontinued and we are not aware of any further development of this compound. Another brain penetrant PDE9 inhibitor developed by Pfizer known as PF-04447943

was originally developed for Alzheimer’s disease and testedthe oxidative stress that is present in patients with SCD. In Pfizer’s Phase 1bSeptember 2019, Emmaus Life Sciences, Inc. withdrew its marketing application to the European Medicines Agency, or EMA, for Endari.

Blood transfusions are another suboptimal treatment option for patients with SCD. Transfusions can transiently bolster hemoglobin levels by adding functional RBCs but can lead to several complications that include iron overload, adverse immune response and transmission of transfusion-associated infections. Due to the lack of uniform accessibility to blood transfusions, they are not widely employed for the treatment of SCD. Allogeneic hematopoietic stem cell transplant, or HSCT, is available as a potentially curative treatment for SCD and acts by halting sickled RBC production from the affected marrow and replacing it with healthy hematopoietic stem cells from a matched donor. HSCT is rarely used due to the difficulty in finding a matched donor, the potential for infection and an approximately 5% mortality rate. The possibility of increased mortality risk relegates this to a last option, often utilized only in the most severe cases.

Due to the limitations of existing therapies, we believe there remains a critical need to develop new preventative therapies that are easy to access, safe for long-term use and address the multiple aspects of SCD pathology.

Emerging Modalities

There has recently been an increased focus on the development of new treatments for SCD with a spectrum of different approaches, but none address the multifactorial pathology of SCD with an oral once-a-day tablet. These approaches can be broadly categorized as follows:

Anti-Polymerization Agents: Anti-polymerization agents, such as Oxbryta, are designed to prevent polymerization of hemoglobin and sickling of RBCs by increasing hemoglobin’s affinity for oxygen and maintaining hemoglobin in an oxygenated state. However, approaches that are solely focused on reducing polymerization may not address the complex symptomology of SCD and the clinical trialimpact of Oxbryta on VOCs remains a question.

HbF Inducers:  HbF inducers seek to reactivate production of HbF in an effort to enhance hemoglobin-oxygen affinity.  Examples include FTX-6058, under development by Fulcrum Therapeutics, Inc., or Fulcrum, and EPI-01, under development by Novo Nordisk A/S, or Novo Nordisk (in collaboration with EpiDestiny, Inc., or EpiDestiny).

PKR Activators:  Pyruvate kinase-R, or PKR, is an enzyme that is involved in the conversion of sugar into energy and is critical for the survival of RBCs. Mutations in PKR cause deficiencies in this process which results in a shortened lifespan for RBCs.  This has led to the hypothesis that PKR activation can overturn this deficiency and may lead to a therapeutic benefit in patients with SCD, there were some reductionsSCD.  Examples include mitapivat (AG-348), under development by Agios Pharmaceuticals, Inc., or Agios, and etavopivat (FT-4202), which is under development by Forma Therapeutics, Inc., or Forma.  

Selectin Inhibitors: Pan selectin and specific P-selectin inhibitors, such as Adakveo, are designed to reduce adhesion of WBCs to the endothelial cell wall and reduce VOCs; however, selectin inhibitors do not ultimately prevent the sickling of RBCs in adhesion markers but no significant HbF inductionSCD. Furthermore, Adakveo requires lengthy infusion treatments every three to four weeks. Global Blood Therapeutics, Inc, or GBT, is also developing inclacumab, a specific P-selectin inhibitor that was observed. Development of PF-04447943 was subsequently discontinuedpreviously under development for non-SCD indications.  

Gene Therapy/Editing: Gene-based therapy is an innovative and we are not aware of any further development of this compound.

Our Solution for Sickle Cell Disease: IMR-687 as a Differentiated PDE9 Inhibitor

Ourpotentially curative approach to address SCD treatment. Like HSCT, gene therapy for SCD involves several pre-treatment steps that can include chemotherapy, which carry significant standalone risks. bluebird bio, Inc., or bluebird, and Aruvant Sciences, Inc., or Aruvant, are each developing gene therapies which aim to deliver a functional copy of the human beta-globin gene.  Gene editing, including CRISPR-Cas9, is fundamentally distinct from other therapies. IMR-687 is being developed to directly and potently inhibit PDE9, which represents a differentiatedan alternative approach to increase cyclic GMP levels,gene modification that has recently advanced in clinical development. Examples of gene editing approaches include CTX-001, currently in development by CRISPR Therapeutics AG, or CRISPR (in collaboration with a selectivity for PDE9 that we believe will make it amenable for long-term use. We recently completed a Phase 2a randomized, double blinded, placebo-controlled clinical trial of IMR-687 in adult patients with SCD and we are currently conducting a Phase 2b clinical trial in this patient population. We believe IMR-687 may have advantages over other therapies, including speed of onset of HbF induction, a multimodal approach and a once daily dosing regimen. In addition, IMR-687 has been shown to be stable at high temperatures and in humid conditions, potentially enabling worldwide access, including in areas where SCD and ß-thalassemia are endemic.

We believe IMR-687 has several differentiating features relative to other PDE9 inhibitors:

Highly Potent PDE9 Inhibitor: IMR-687 is a highly potent PDE9 inhibitor, as measured by induction of cyclic GMP across various doses. We have specifically studied the potency of PDE9 inhibition of IMR-687 as compared to HU and analogues of BAY73-6691 and PF-04447943 by analyzing cyclic GMP levels across various doses in an in vitro assay. We studied analogues of BAY73-6691 and PF-04447943 because BAY73-6691 and PF-04447943 are proprietary compounds to which we did not have direct access. The analogues we used were based on the well-defined crystal structures of BAY73-6691 and PF-04447943 that are publicly available in published patent filings. When compared to these agents, IMR-687 was observed to be more potent across all dose groups.

Differentiated Selectivity and Tolerability Profile: IMR-687 is a highly selective PDE9 inhibitor. We compared the selectivity of IMR-687 and an analog of PF-04447943 against a panel of related PDEs. We chose not to test BAY73-6691Vertex Pharmaceuticals Incorporated, or an analog thereof because BAY73-6691’s lack of potency led us to conclude there was little merit to further testing. For the isoform PDE9A1, IMR-687 was observed to be more than eight times more selective than the PF-04447943 analog and for the isoform PDE9A2, IMR-687 was observed to be more than four times more selective than the same compound. Isoforms are functionally similar proteins within each PDE family that have slightly different genetic coding. We believe the selectivity of IMR-687 will allow us to optimize dose while minimizing off-target effects. IMR-687 has exhibited lower interaction with other PDE family members compared to the PF-04447943 analog, or did not have measurable inhibition.

We also conducted toxicology studies of IMR-687. In a 26-week female rat infertility study and in early embryonic development studies, once-daily dosing of IMR-687 was observed to be well tolerated with no effects on fertility or embryonic development at any dose level studied. In addition to standard adult animal toxicology studies, a juvenile rat study was completed where once daily administration of IMR-687 was observed to be well tolerated with no indication of toxicity.

Minimal Brain Penetration: We are developing IMR-687 specifically because it was observed to have low brain penetration in animal models. We believe this will reduce the potential impact of PDE9 inhibition on central nervous system, or CNS, development and function. Historically, most early PDE9 inhibitors were developed for potential CNS indications and thus were specifically designed to cross the blood-brain barrier. We observed in a mouse model that while plasma concentrations were similar, brain exposure to levels of IMR-687 were observed to be five times lower than those seen with the PF-04447943 analog at 10mg/kg.

Additionally, IMR-687 showed no effect on locomotor activity or in a classical fear conditioning mouse model of learning and memory. In contrast, the brain penetrant PF-04447943 analog was observed to significantly increase conditioned fear responses in mice at an equivalent dose.

Drug Product Stability: IMR-687 has been observed to exhibit a durable shelf life at both standard and elevated room temperature and humidity conditions. For example, at standard room temperature and humidity conditions, we have observed consistent stability results at doses of 50 mg, 100 mg, and 200 mg at the 24-month time point. In addition, we have observed consistent stability results under accelerated stress conditions that mimic the high heat (40° Celsius, 104° Fahrenheit) and increased humidity (75%) of the tropics. We believe this observed stability of IMR-687 provides us with a potential opportunity to treat patients in areas where other treatments may not be accessible, including in the tropical climates where SCD and β-thalassemia are endemic.

Preclinical and Phase 1 Data

In preclinical SCD models, we observed that IMR-687 is a potent cyclic GMP inducer and had a multimodal mechanism of action, acting to increase RBC HbF expression, reduce RBC sickling and decrease expression of WBC adhesion molecules.

In an SCD in vitro model, we measured the ability of IMR-687 to increase cyclic GMP levels in an RBC cell line as compared to HU. In this study, we observed that IMR-687 induced cyclic GMP production in a dose-dependent manner at an approximately 30-fold lower drug concentration than HU. In addition, at an equivalent drug concentration of 10 µM of IMR-687, we observed an approximately ten-fold increase in cyclic GMP levels as compared to HU. We also evaluated IMR-687 in a mouse model of SCD that expresses human sickle hemoglobin. We observed that IMR-687 demonstrated statistically significant increases in HbF-positive RBCs, statistically significant decreases in the percentage of sickled RBCs and decreases in markers of hemolysis, or destruction of RBCs, and WBC adhesion.

In our Phase 1 randomized, double-blind, placebo-controlled clinical trial in healthy volunteers, single and multiple ascending doses of IMR-687 were reported to be well tolerated to a maximum dose of 4.5 mg/kg per day and no serious adverse events were reported.

IMR-SCD-102: SCD Phase 2a Clinical Trial

Our Phase 2a clinical trial was a randomized, double-blind, placebo-controlled clinical trial in adult patients with the HbSS and HbS/ß-0 thalassemia genotypes of SCD and was conducted at clinical centers in the United States and the United Kingdom. The trial evaluated the safety, tolerability, PK and exploratory PD and clinical outcomes of IMR-687 in two groups of SCD patients: patients receiving IMR-687 administered as a monotherapy agent once daily for 24 weeks and patients receiving IMR-687 administered at lower doses in combination with HU for 16 weeks. The design of the Phase 2a trial separated out the monotherapy and combination arms into separate sub-studies. The combination sub-study was purposefully designed in consultation with the FDA, taking into account HU and IMR-687’s overlap in the nitric oxide-cyclic GMP pathway, which ultimately drives cyclic GMP expression. This low-dose, short duration sub-study was thus created to test how the two drugs interact when dosed in combination. Patients in the combination sub-study were required to have been receiving HU for at least 60 days prior to screening and then continue to receive the same dose of HU throughout the duration of the trial. A total of 93 patients were dosed in the trial, of which 58 patients were dosed in the monotherapy sub-study and 35 patients were dosed in the combination sub-study.

We initially commenced the monotherapy sub-study with patients receiving IMR-687 at doses of 50 mg or 100 mg through 12 weeks and then escalating to higher doses of 100 mg or 200 mg, respectively, through 24 weeks if approved by the Safety Review Committee, or SRC, after review of vital signs and treatment emergent adverse events, or TEAEs. After dosing 40 monotherapy patients (referred to as Pop A), in the second quarter of 2019 we amended the trial protocol for the monotherapy sub-study to (i) accelerate the time of dose escalation for the 100 mg/200 mg dose group from week 13 to the end of the first month, (ii) allow for patients to be administered the higher dose for five months instead of three months and (iii) eliminate the 50 mg/100 mg dose group. Following the amendment of the protocol, we dosed a further 18 patients (referred to as Pop A1) in the monotherapy sub-study. All patients in the monotherapy sub-study who were dosed with placebo continued to receive placebo for the duration of the trial.

We initially commenced the combination sub-study with patients receiving IMR-687 at an initial dose of 50 mg on top of a stable dose of HU, with escalation after one month to 100 mg for the remaining portion of the trial (through week 16) upon SRC approval. After dosing 21 combination patients (referred to as Pop B), in the second quarter of 2019, we amended the trial protocol for the combination sub-study to extended dosing for an additional month. Following the amendment of the protocol, we dosed a further 14 patients (referred to as Pop B1) in the combination sub-study. All patients in the combination sub-study who were dosed with placebo continued to receive placebo for the duration of the trial. The design of the Pop A/A1 and B/B1 sub-studies are shown in the graphics below.

We conducted two planned interim analyses of data from our Phase 2a clinical trial as described below.

November 2018 Interim Analysis

The first interim analysis was blinded at the individual patient level and consisted of an evaluation of low dose IMR-687 in at least 18 patients that had completed one month of treatment in the Pop A monotherapy sub-study and was carried out as pre-specified in the protocol. The data cut-off for this interim analysis was October 8, 2018. At 13 weeks, we observed an increase of approximately 110% from baseline in the percentage of F-cells in the group receiving 100 mg of IMR-687 as monotherapy. We also observed decreases in absolute reticulocytes and percent reticulocytes in the 100 mg IMR-687 monotherapy group. The data for WBC and adhesion markers were inconclusive. Blinded safety and tolerability data as of the data cutoff date showed that treatment with IMR-687 was reported to be generally well tolerated, with no clinically significant changes in WBC counts and no evidence of neutropenia.

August 2019 Interim Analysis

The second interim analysis was triggered when at least 18 patients completed the 24 weeks of dosing in this trial in the Pop A monotherapy sub-study and had a cut-off date of July 8, 2019. Patients in the Pop B combination sub-study were evaluated for the first time to measure safety and PK related to HU being dosed in combination with IMR-687. In the second interim analysis, IMR-687 was generally reported to be well tolerated across all doses in the monotherapy and combination sub-studies.

All Comers Analysis (n=37)

The first analysis involved all Pop A monotherapy patients, regardless of where they were in the trial, referred to as all comers. We observed a statistically significant (p=0.022) increase in F-cells for the IMR-687 high dose cohort (100 mg/200 mg) compared to placebo after 24 weeks of dosing. We observed a relative increase in F-cell percentage of 18.1 percentage points, with the mean values for the absolute percentage of F-cells observed in patients increasing from 13.6% to 31.7%Vertex).  We observed a mean absolute increase in HbF% of 1.7 percentage points in the IMR-687 high dose cohort (100 mg/200 mg) after 24 weeks of dosing. Patients in the IMR-687 high dose cohort had a mean baseline HbF% of 6.7%, which increased to 8.4% after 24 weeks of dosing.

In addition, we observed a mean increase in mean corpuscular volume of 4.3 femtoliters in the IMR-687 high dose cohort. While we saw individual changes in other related downstream RBC biomarkers (including variable responses in reticulocytes, LDH, indirect bilirubin and hemoglobin) and white cell adhesion biomarkers (including sP-selectin, sE-selectin, iVCAM-1 and iCAM-1), we did not see consistent trends across the mean values.

Completer Analysis (n = 18)

The second analysis was a pre-specified protocol-driven analysis of the efficacy parameters for the 18 completers. For the measurements of F-cells, 100% of completers showed an increase in F-cells and no completer saw a decrease in F-cells in the high dose arm (100 mg/200 mg). While there was more variability in the lower dose arm (50 mg/100 mg), most completers saw F-cell increases, though they did not have the magnitude of increases as observed for the higher dose (100 mg/200 mg).  Placebo completers, as expected, showed the most variability in changes in F-cells, with 50% showing increases in F-cells and 50% showing decreases, netting out to an overall slight decrease in F-cells. These data allowed us to create a relevant PK/PD model to potentially provide greater understanding of how dose impacts efficacy markers, including F-cells and HbF%.  

Pharmacokinetics (PK) Summary

PK data from the monotherapy sub-study were analyzed to compare IMR-687 exposure for patients in the Phase 2a trial to exposure observed in preclinical studies and in healthy volunteers in the multiple ascending dose stage of our Phase 1 trial, in each case through an analysis of Area Under the Curve_0-24, or AUC_0-24, which measures drug concentration in blood plasma over the first 24 hours following dosing. As shown in the far-left column of the figure below, a preclinical female dog model established a No Observed Adverse Effect Level, or NOAEL, which is the highest experimental point that does not have adverse effects, of 90,239 hours x ng/mL, or h x ng/mL. As shown in the second-from-left column of the figure below, the 6 mg/kg highest dose in the fasted single ascending dose stage of our Phase 1 trial resulted in a mean exposure of 31,000 h x ng/mL. As shown in the set of middle columns of the figure below, exposure in the fed multiple ascending dose stage of the trial ranged from 5,630 h x ng/mL at a dose of 1 mg/kg to 23,930 h x ng/mL at a dose of 4.5 mg/kg, which was the maximum tolerated dose, or MTD. As shown in the far-right columns of the figure below, mean exposure in the interim analysis of the Phase 2a trial ranged from 2,880 h x ng/mL at the 50 mg dose to 16,300 h x ng/mL at the 200 mg dose. Also as reflected in the far-right columns in the figure below, we generated a PK model based on these values that predicted exposure of 21,976 h x ng/mL and 32,000 h x ng/mL for possible future higher doses of 300 mg and 400 mg, respectively. The observed mean exposure for 200 mg dosing of IMR-687 in the interim analysis of the Phase 2a trial and the predicted exposure for 300 mg dosing of IMR-687 are below the mean exposure at the 4.5 mg/kg MTD in the multiple ascending dose stage of our Phase 1 trial and are less than 25% of the NOAEL observed in preclinical dog experiments. While the predicted exposure for 400 mg dosing of IMR-687 surpasses the mean exposure at the 4.5mg/kg MTD in the multiple ascending dose stage of our Phase 1 trial, it is substantially lower than the established female dog NOAEL. We believe the exposure data we have observed to date and the exposure data predicted by our PK modeling support our decision to increase dosage to 300 mg, and potentially 400mg, in our ongoing Phase 2b clinical trial in SCD.

The second interim analysis also included analyses of additional PK exposure metrics from the monotherapy sub-study, including C_max values, which are the peak concentrations achieved by a drug, and concentrations of a drug after 24 hours, or C₂₄ values. The C₂₄ parameter provides an understanding of target coverage over a 24-hour period and is particularly

important when matched with the measure of inhibitory concentrations above 90%, or IC₉₀. We estimated an IC₉₀ value of 160 ng/mL for IMR-687 from the in vitro dose-response curve using IMR-687 in combination with the isolated PDE9 enzyme. Patients in the 50 mg/100 mg group of the monotherapy sub-study were, on average, above this estimated IC₉₀ for approximately six to 12 hours, depending on dose, and patients in the 100 mg/200 mg group were, on average, above this estimated IC₉₀ for approximately 12 to 17 hours, depending on dose. Our PK modeling predicts that a 300 mg dose of IMR-687 will result in concentrations above the estimated IC₉₀ for approximately 22 hours and a 400 mg dose will result in concentrations above the estimated IC₉₀ for over 24 hours. In addition, the C_max and C₂₄ levels observed for 200 mg dosing and predicted for 300 mg dosing of IMR-687 were below those observed at the 4.5 mg/kg MTD dose in the multiple ascending dose stage of our Phase 1 trial. Our PK modeling predicts that the C_max and C₂₄ levels for 400 mg dosing of IMR-687 will be higher than those observed at the 4.5 mg/kg MTD in the multiple ascending dose stage of the Phase 1 trial.

Examination of the of the PK for the combination of IMR-687 + HU as compared to HU alone was the key objective for the combination sub-study of the Phase 2a trial and was recommended by the FDA in our pre-IND discussions. We measured HU PK on its own prior to the commencement of combination dosing as well as HU PK following the commencement of combination dosing at weeks five and 17. The PK data in the second interim analysis indicated that treatment with IMR-687 + HU did not result in changes in the HU PK observed prior to combination dosing and that there were no drug-drug interactions between IMR-687 and HU, which we believe supports our use of higher doses of IMR-687 in combination with HU in our Phase 2b clinical trial of IMR-687 in SCD. These findings also allowed us to combine monotherapy and combination dosing into a single trial population for our ongoing Phase 2b clinical trial of IMR-687 in SCD.

PK/PD Modeling with Completer Data

Noncompartmental PK results were combined with the completer data from the second interim analysis to establish PK/PD correlations for use in connection with our Phase 2b trials. There were two key correlations that helped us better understand HbF response in light of the PK data. The first of these was the correlation between F-cell response data and PK data. We defined responders as patients that had a ≥7% increase from baseline, which included all patients from the 100 mg/200 mg dose group and one patient from the 50 mg/100 mg dose group (total n=6). PK/PD analysis showed that completers that responded to IMR-687 had both higher median AUC_0-24 and C_max valuesNumerous questions remain with respect to IMR-687 as comparedthe gene editing approach, including off-target mutagenesis and the ultimate potential reach of such therapeutics. More studies are needed to completer non-responders. Although the median C₂₄ values were similar for all completers, the 25thestablish durability and 75th percentile values were higher for responders.

The second correlation we examined was between HbF response data and PK data. We defined responders as patients that had a ≥1% absolute increase in HbF from baseline, which included three patients from the 100 mg/200 mg dose group and one patient from the 50 mg/100 mg dose group (n =4). Similar to what we observed in our analysis of the F-cell data, PK/PD analysis showed that completers that responded to IMR-687 had higher median AUC_0-24 levels as compared to non-responders. While the median C₂₄ and C_max values were similar for all completers, the 25th and 75th percentile values for C₂₄ were higher for responders.

Future dose modeling predicts that exposure in AUC_0-24, C_max and C₂₄ for IMR-687 should increase with dose levels above 200 mg and should achieve drug concentration levels above the estimated IC₉₀ for approximately 22 hours at a 300 mg dose and over 24 hours at a 400 mg dose. We believe this PK/PD modeling further justifies our evaluation of higher doses of IMR-687 in our Phase 2b clinical trials.

January 2021 Topline Results

In January 2021, we disclosed topline results of the Phase 2a clinical trial, which are summarized below.  We are continuing to conduct additional analyses with respect to this data, including final PK data, and expect to report results from these additional analyses at a future medical meeting in 2021.  

As described above, in the second quarter of 2019 we amended the trial protocol for the monotherapy sub-study to create Pop A1, which was comprised of patients who received either placebo or IMR-687 at a once-daily dose of 100 mg through 4 weeks and then 200 mg for an additional 20 weeks (24 weeks total).  At the same time, we amended the trial protocol for the combination sub-study to create Pop B1, which was comprised of patients who received either placebo or IMR-687 once-daily at 50 mg on top of a stable dose of standard of care HU, with escalation after 4 weeks to 100 mg for an additional 20 weeks (24 weeks total).  None of the patients enrolled in Pop A1 or Pop B1 were included as part of the August 2019 interim analysis described above.

Summary of Safety and Tolerability Data

Overall, the data demonstrated that IMR-687 was well tolerated as a monotherapy and in combination with HU at all dose levels. In the monotherapy sub-studies (Pop A and Pop A1), the most frequent adverse events in the IMR-687 treatment arm included sickle cell anemia with crisis, nausea, headache and back pain.  In the combination sub-studies (Pop B and Pop B1), the most frequent adverse events in the IMR-687 + HU treatment arm included headache, sickle cell anemia with crisis, nausea, fatigue and ocular icterus. There were no observed clinically significant shifts in vital signs or electrocardiogram data, including no hypotension or neutropenia in either the monotherapy or combination arms.

A 30% lower rate of VOCs/SCPCs, as part of the safety analysis, was observed in the Pop A1 IMR-687 treatment group when compared to placebo. 58% of patients (7 of 12 patients, 9 events total) experienced at least one VOC/SCPC in the Pop A1 IMR-687 treatment group as compared to 83% (5 of 6 patients, 14 events total) in the placebo population. Furthermore, the rate of VOC-related hospitalizations was lower in the Pop A1 IMR-687 treatment group when compared to placebo. 33% of patients (4 of 12) experienced one VOC-related hospitalization in the Pop A1 IMR-687 treatment group as compared to 66% (4 of 6) in the placebo population.  There were no meaningful differences in VOCs/SCPCs or VOC related hospitalizations, between the Pop B1 IMR-687 + HU and HU + placebo groups.

Population A1 Monotherapy (n=18)

Biomarker results showed minimal changes in F-cells, HbF levels and total Hb levels from baseline through week 24. However, a dose-dependent increase in HbF (1.3% absolute increase) was seen when patients dose escalated from 100 mg to 200 mg, starting after 4 weeks (n=10) and through 24 weeks (n=7). One of seven evaluable patients (14%) in Pop A1 recorded an absolute increase in HbF percentage from baseline of greater than 1% (increase of 3.2%). Placebo patients from Pop A1 did not have evaluable week 24 PD biomarker results due in part to missing study visits and are therefore not included in the table below. Biomarkers related to hemoglobin, hemolysis, inflammation, and cardiac stress are summarized below for the IMR-687 treatment arm:

* With respect to F-cell percentage, n=9 at baseline and n=6 at Week 24.

Population B1 Combination Therapy (n=14)

Biomarker results in IMR-687+HU treated patients showed an overall increase in F-cells and HbF levels from baseline to week 24, while Hb levels did not meaningfully change. Three of the eight evaluable patients (33%) had absolute increases in HbF percentage of greater than 1%, with a mean absolute increase in HbF percentage of 4.3% in that subset of patients. There was a single placebo patient from Pop B1, as other patients did not have evaluable week 24 pharmacodynamics biomarker data due in part to missing study visits. Therefore, this single patient is not included in the table below.

Biomarkers related to hemoglobin, hemolysis, inflammation, and cardiac stress are summarized below for the IMR-687+HU treatment arm:

* With respect to F-cell percentage, n=8 at baseline and n=7 at Week 24.

Population A Monotherapy (n=40)

Subsequent to the August 2019 interim analysis described above, four additional patients completed 24 weeks of dosing in the Pop A monotherapy arm. A completers analysis in this group showed that the high dose of IMR-687 (100 mg/200 mg) resulted in an absolute increase in F-cell percentage of 13.3% from baseline (p=0.025) and a mean absolute increase in HbF percentage from baseline of 0.9%. Three of the eight evaluable patients (38%) in Pop A recorded absolute HbF percentage increases of greater than 1%, with a mean absolute increase in HbF percentage of 3.1% in that subset of patients.

We are in the process of conducting multiple post-hoc analyses of the Phase 2a clinical trial data that include, amongst other analyses, reviewing pooled data across the sub-studies from the trial.  Preliminary review of certain of these analyses demonstrate potential benefits from IMR-687 with respect to certain SCD biomarkers, including F-Cells.  We expect to report results from these analyses at a future medical meeting.treatments.

Phase 2a Open Label Extension

We are conducting a four-year OLE clinical trial which allows patients from the Phase 2a clinical trial to enroll in a long-term safety and tolerability study of IMR-687 following completion of the Phase 2a clinical trial. The OLE clinical trial was initially designed so that patients were administered a daily dose of 100 mg of IMR-687, and in the second quarter of 2020, a protocol amendment increased the daily dose to 200 mg.  Patients from the combination sub-study continue to receive the same dose of HU that they received while on the Phase 2a clinical trial throughout the duration of the OLE clinical trial. Based on the tolerability profile of IMR-687 observed thus far in the OLE clinical trial, the safety review committee, or SRC, has approved, subject to the contingency below, dose escalation in the OLE clinical trial to a minimum daily dose of 300mg, with certain patients being eligible for a daily dose of 400mg based upon their weight.  This weight-based approach is similar to that being used in our ongoing Ardent Phase 2b clinical trial in SCD.   The SRC approved the dose adjustments contingent on the independent data monitoring committee, or DMC, for the Ardent Phase 2b clinical trial in SCD opening the higher-dose IMR-687 arm of that trial.  We expect the Ardent Phase 2b clinical trial DMC to make a decision on opening the higher dose arm in March 2021.

We conducted a preliminary review of 24 patients enrolled in the OLE clinical as of December 31, 2020.  As of data cutoff date, approximately 12 of these patients had evaluable PD biomarker data for at least four months of treatment on the OLE clinical trial.  We organized the patients with evaluable PD biomarkers into two sub-groups.  The first sub-group, which we refer to as the treatment interrupted sub-group, was comprised of approximately 8 patients who initiated treatment on the OLE clinical trial more than 12 weeks after completing treatment for the Phase 2a clinical trial.  The second sub-group, which we refer to as the direct roll-over sub-group, was comprised of approximately 4 patients who initiated treatment on the OLE clinical trial within 12 weeks of completing treatment for the Phase 2a clinical trial.  For purposes of analyzing PD biomarker results, patients in the direct roll-over sub-group were analyzed using the baseline value from the Phase 2a clinical trial, while patients in the treatment interrupted sub-group were analyzed using a new baseline established upon initiation of the OLE clinical trial.

Four-Month Data Review

Overall, data from the 24 patients enrolled in the OLE clinical trial as of December 31, 2020 demonstrated that IMR-687 was well tolerated.  The most common adverse events (in more than 5% of subjects) were sickle cell anemia with crisis, headache, pain in extremity, nausea, upper abdominal pain and back pain, and were generally consistent with those observed in the Phase 2a clinical trial.  16 of the 24 patients (67%) experienced at least one adverse event, with a majority of the adverse events being mild or moderate in severity. There were no observed clinically significant shifts in vital signs, safety laboratory data, or electrocardiogram data.

Biomarker results demonstrated increases in both HbF and F-cells after four-months of treatment in both the treatment interrupted sub-group and the direct roll-over sub-group.  Specifically, there was a mean absolute increase in HbF percentage of 1.7% and 2.3% in the treatment interrupted sub-group and direct roll-over sub-group, respectively, and a mean absolute increase in F-cells of 5.9% and 10.2% in the treatment interrupted sub-group and the direct roll-over sub-group, respectively, in each case after four months of treatment. There were minimal changes in total Hb in both sub-groups.  Patients in the treatment interrupted sub-group also demonstrated improvements in several markers of hemolysis after four months of treatment, whereas the direct roll-over sub-group showed variable changes in these measures.

The preliminary biomarker results for the OLE clinical trial are shown in the table below.

* Patients in the direct roll-over sub-group did not have data for NTproBNP or CRP as of December 31, 2020.

We are in the process of analyzing outcomes with respect to VOCs from the OLE clinical trial and expect to report this information at a future medical meeting.

Case Narratives

In the third quarter of 2020, we presented case narratives on the first two patients in the OLE clinical trial to complete at least six-months of treatment.  Below we have provided an update on each of these two patients who remain on the OLE clinical trial as of the filing of this Annual Report on Form 10-K.

Patient #1 was part of the Pop A monotherapy sub-study of the Phase 2a clinical trial and enrolled in the OLE clinical trial shortly following completion of the Phase 2a clinical trial and was therefore a direct roll-over patient.  As of December

31, 2020, Patient #1 had been on the OLE clinical trial for approximately 18 months (and on IMR-687 for 24 months) and has shown continued increases in levels of HbF and F-cells, as well as improvements in several SCD disease biomarkers.  

The table below presents biomarker results for this patient at baseline, 12 months on study (as presented in the third quarter of 2020) and 18 months on study (the most recent OLE visit for this patient):

* As Patient #1 was a direct roll-over patient, baseline was established using the baseline of the Phase 2a clinical trial (mean of screening and randomization values).

In addition, a comparison of VOC data for the 24-month period that Patient #1 has been on IMR-687 (six months on the Phase 2a and 18 months on the OLE) versus information from a retrospective review of the patient’s medical records for the 24-month period prior to initiation of IMR-687 indicate potential benefits of IMR-687.  In the 24-month period on IMR-687, the patient had a 64% reduction (55 to 20 events) in reported VOCs, as compared to the 24-month period prior to IMR-687 administration.

Patient #2 was part of the HU combination sub-study in the Phase 2a clinical trial and was randomized to the placebo dose group, and therefore never received IMR-687 during the Phase 2a clinical trial.  The patient started the OLE clinical trial 14 months after completing the Phase 2a clinical trial, and was therefore a treatment interrupted patient, but remained on a stable HU dose (3000mg daily) during this interim period and while on the OLE clinical trial.  As of December 31, 2020, we had data on Patient #2 through eight months of treatment, reflecting the most recent OLE visit for this patient.  Patient #2 has shown sustained increases in levels of HbF and F-cells over baseline, however this patient has also shown increasing variability in other SCD biomarkers subsequent to the original case narrative presented in August 2020.  

The table below presents biomarker results for this patient at baseline, four months on study (as presented in the third quarter of 2020) and eight months on study (the most recent OLE visit for this patient):

* As Patient #2 was a treatment interrupted patient, baseline was reestablished upon initiation of the OLE clinical trial (to the extent each are available, mean of baseline at screening and initiation of treatment).

In addition, a comparison of VOC data for Patient #2 for the eight-month OLE clinical trial period versus information from a retrospective review of the patient’s medical records for the eight-month period prior to initiation of the OLE clinical trial indicate potential benefits of IMR-687 being administered in combination with HU.  In the eight-month period on IMR-687, the patient had a 69% reduction (16 to 5 events) in reported VOCs, as compared to the eight-month period prior to IMR-687 administration.

We caution that the case narratives reflect data from only two patients at specified intervals in the OLE clinical trial and reported VOC comparisons involve retrospective reviews of the patients’ medical records.  As a result, we cannot assure you that future data on these patients will continue to be favorable or that data on other patients in the OLE clinical trial will demonstrate potential benefit of IMR-687. We plan to present more data on these patients at future medical meetings.

Ardent Phase 2b Clinical Trial of IMR-687 in SCD

In the second quarter of 2020, we initiated a Phase 2b clinical trial, which we refer to as the Ardent trial, of IMR-687 in SCD and enrollment is ongoing. The Ardent trial is designed as a randomized, double-blind, placebo-controlled, multicenter study of approximately 99 patients, aged 18 to 65 years with SCD and one to 12 VOC episodes within the 12 months preceding enrollment. Patients concomitantly receiving a stable dose of HU according to the patient’s established treatment plan are eligible for enrollment. Patient randomization will be stratified by use of HU as well as by region. We plan to utilize weight-based dosing due to the possible wide range of patient weights in the trial and the increased drug exposure resulting from our use of 300 mg and 400 mg doses. We believe this use of weight-based dosing will more precisely manage drug exposure and tolerability, so that patients with below average weights do not receive too high of a dose and patients with above average weight do not receive too low of a dose. The lower-dose IMR-687 arm will test a range of 3.0 mg/kg up to 4.5 mg/kg (including up to a 300 mg dose) and patients will be randomly assigned in a 2:1 ratio to receive either IMR-687 or placebo. The higher-dose IMR-687 arm will test a range of 4.5mg/kg up to 6.7 mg/kg (including up to a 400 mg dose). Prior to enrolling the higher-dose IMR-687 arm, the independent DMC will review the then-available safety and tolerability data and, if the DMC recommends inclusion of the higher dose, randomization will then proceed in a 1:2:1 ratio (IMR-687 lower dose, IMR-687 higher dose or placebo). We expect the DMC to make a decision on opening the higher-dose IMR-687 arm in March 2021. The dose levels to be administered in the Ardent trial are designed to provide meaningful exposure to IMR-687 that could be up to two-fold that employed in the Phase 2a trial and utilize the 300 mg and potentially 400 mg dose for the first time.

The planned primary efficacy objective of the Ardent trial is to evaluate the proportion of patients with HbF response, defined as an increase of ≥3% in HbF from baseline to week 24, compared to placebo, and the trial is powered for statistical significance with respect to this endpoint. Planned secondary objectives include the evaluation of the effect of IMR-687 versus placebo on (i) HbF-associated biomarkers, (ii) indices of red cell hemolysis, (iii) indices of WBC adhesion, (iv) the incidence of VOCs in relation to HbF levels, and (v) quality of life measures. In addition, the Ardent trial will examine exploratory clinical endpoints, based in part, on the published FDA-ASH Guide to Clinical Development of Sickle Cell Disease Therapies. While the primary efficacy endpoint for the trial will assess results after 24 weeks of treatment, patients will continue on treatment through 52 weeks to provide data for additional exploratory endpoints and to measure the incidence of VOCs over the course of a one-year period. Following the completion of 52 weeks of dosing in the trial, patients will be eligible to enroll in an open-label extension study. In addition, there are pre-specified interim analyses planned in the trial, with the first such interim analysis being conducted when 33 patients have reached 24 weeks of dosing. We expect to report data from this first interim analysis in the second half of 2021.

Our systematic literature review and series of meta-analyses support our belief that HbF has the potential to predict clinical benefit and thus could serve as a surrogate endpoint for accelerated approval in SCD. Drugs that could qualify for accelerated approval are those that treat a serious or life threatening condition, generally provide a meaningful advantage over available therapies, and demonstrate an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, or IMM, that is reasonably likely to predict an effect on IMM or other clinical benefit.

In the first quarter of 2020, we held a face-to-face Type B meeting with the FDA under our Fast Track designation for IMR-687 to discuss both the potential for HbF to serve as a surrogate endpoint for accelerated approval as well as the design of later stage SCD trials seeking to establish the effect of HbF on important clinical outcomes in SCD. In the preliminary meeting comments, the FDA recommended that we conduct a Phase 2b dose finding trial instead of a Phase 2b/3 trial design that we proposed. At the Type B meeting, the FDA commented that our revised Phase 2b trial design and approach to data collection to support HbF as a potential surrogate endpoint was acceptable. The FDA also stated that it would welcome further discussion as the data from the Phase 2b trial matures to discuss the concept of the acceptability of HbF and a potential threshold of 3% from baseline as an acceptable surrogate endpoint. The FDA stressed the importance of defining clear and strong assumptions and having robust results, which would be evaluated by the FDA to test if 3% HbF or higher would provide meaningful clinical benefit and therefore constitute an acceptable surrogate endpoint for a future pivotal trial of IMR-687 in SCD.

Pediatric Development Program of IMR-687 in SCD

We currently anticipate initiating our pediatric clinical program of IMR-687 in SCD in the first half of 2021. We expect to conduct a Phase 1/2 clinical trial in adolescents (12-17 years old) comprised of a single ascending dose, followed by a 36-week multiple dose expansion phase. In December 2020 we held a Type C meeting with the FDA, during which the agency expressed general alignment with the overall clinical trial design and indicated the study could be submitted with the adult study data in the same NDA.

SAD/MAD Clinical Study in Health Volunteers

In the first half of 2021, we expect to initiate a single ascending dose, or SAD, followed by a multiple dose clinical trial of IMR-687 to explore the safety, tolerability, and PK of higher doses of IMR-687. This short duration study in healthy volunteers under fed conditions will sequentially assess doses of IMR-687 up to 800 mg per day administered once daily or twice daily. Based on the safety, tolerability and PK profile observed in the SAD portion of the trial, the multi-dose portion of the trial will evaluate multiple doses of IMR-687 at the maximum tolerated dose observed for both the once daily and twice daily administrations from the SAD portion of the trial.

β-thalassemia Disorder Overview

β-thalassemia, which is part of the second group of hemoglobinopathies, is a rare inherited RBC disorder. Unlike patients with SCD, patients with β-thalassemia have a mutation that causes the absence or decreased synthesis of the beta globin subunit of hemoglobin, thereby creating an over-abundance of the alpha globin subunit. This causes the formation and aggregation of insoluble clumps that lead to ineffective RBC production and a reduction in the number of functioning RBCs. Furthermore, the RBCs that do survive have shorter lifespans and are smaller, paler and less efficient at transporting oxygen throughout tissues of the body. Oftentimes, RBCs of smaller size, measured as mean corpuscular volume, is a first indication of β-thalassemia prior to genotyping. If left untreated, β-thalassemia causes severe anemia, splenomegaly, skeletal abnormalities, organ failure and early death.

β-thalassemia presents as a spectrum of disease, with patients categorized based on hemoglobin levels and clinical manifestations. Although β-thalassemia can be classified as “major,” “intermedia,” and “minor,” a more recent classification is based on a patient’s dependency on blood transfusion. Most β-thalassemia major patients are classified as TDT, while intermedia and minor patients are classified as NTDT. TDT patients have a transfusion regimen that is well established and generally lifelong. NTDT patients are a clinically diverse group, with transfusions required intermittently during periods of RBC stress, such as pregnancy, infection, surgery, times of rapid growth and sometimes later in life.

As in SCD, a promising way to address the missing or decreased presence of the beta globin subunit is to induce HbF production. In addition to resolving persistent anemia, HbF induction rectifies the missing or mutated beta globin subunit and thereby reduces the overabundance of free-floating alpha globin subunits. These benefits have the potential to result in increased functional RBC production, higher hemoglobin levels, reduced hemolysis and the reduction of adhesion and inflammation. Like in SCD, infants with β-thalassemia major do not present clinical symptoms of their disorder until age six to 24 months, and sometimes later, when their HbF is replaced by mutated adult hemoglobin. Natural history data show that patients with β-thalassemia who have high HbF levels, due to hereditary persistence of HbF, have less severe forms of the disorder. In addition, genetic variations associated with increased HbF production have been shown to correlate with reduced β-thalassemia severity.

The image below depicts how RBCs and hemoglobin can change as a result of gene mutations in β-thalassemia. In healthy individuals, there are equal amounts of alpha globin and beta globin subunits, which form normal hemoglobin. In β-thalassemia, the absence and/or mutation of beta globin subunits cause excessive alpha subunits that often aggregate into clusters. In cells with reactivated HbF, the gamma subunit reduces the effects of free-floating alpha chains and may improve hemoglobin efficiency and RBC health.

The potential of HbF induction has been observed through off-label use of HU to treat patients with β-thalassemia and has been explored in numerous clinical trials in both NTDT and TDT patients. Most of these efforts were not randomized controlled trials, and many of them lacked a placebo comparator. Nevertheless, HbF induction by HU showed promising early response in TDT and NTDT patients. In fact, there are numerous documented cases both in clinical trials and in off-label real world use where TDT patients have a reduced need for transfusions with continued HU treatment. Despite these observed benefits, and similar to SCD, there continue to be limitations with HU as a therapy in β-thalassemia, including its toxicity, dosing schedule and potential long-term effects.

In addition to HbF induction, independent research suggests activation of the nitric oxide-cyclic GMP signaling pathway may induce RBC production, which is associated with increases in RBC counts and hemoglobin levels. We believe this is an important mechanism of action to that could be relevant in reducing disease burden. Furthermore, adhesion mediators are also highly upregulated in patients with β-thalassemia and may contribute to the increased number of clots in their blood vessels, known as a hypercoagulability state. Specifically, data show that two adhesion markers, ICAM-1 and VCAM-1, are over-expressed in patients with β-thalassemia as compared to controls. Furthermore, there is evidence that WBCs in patients with β-thalassemia express higher levels of CD11b and CD18, two important biomarkers in the WBC activation cascade. In preclinical SCD studies, we observed that IMR-687 reduced levels of CD11a and CD11b and CD18.

Addressable Patient Population

The prevalence of β-thalassemia globally is estimated to be 288,000, with an incidence of 60,000 births per year. The total combined prevalence of β-thalassemia in the United States and European Union is estimated to be approximately 19,000 patients. Of the patients currently treated in the United States and European Union, we believe approximately 50% and 10%, respectively, are transfusion dependent. β-thalassemia is especially prevalent in developing countries of Africa, South Asia, Southeast Asia, the Mediterranean region and the Middle East. Although historically prevalent in Mediterranean North Africa and South Asia, thalassemias are now encountered in other regions as a result of changing migration patterns. As such, there is a growing focus on developing new therapeutics aimed at improving quality of life for this significant unmet medical need.

Approved and Emerging Modalities and Their Limitations

Approved Treatments

Managing SCD and its various clinical manifestations is complex, and patients have historically had limited options for treatment. In November 2019, the FDA granted accelerated approval for Oxbryta (voxelotor) for the treatment of SCD in patients 12 years of age and older and its label has subsequently been expanded to include patients four years of age and older. In February 2022, the European Commission approved Oxbryta for the treatment of hemolytic anemia in patients with SCD 12 years of age and older. Oxbryta is an oral therapy taken once daily and is the first approved treatment that directly inhibits sickle hemoglobin polymerization. In November 2019, the FDA also approved Adakveo (crizanlizumab), which has been demonstrated to reduce the frequency of VOCs in adult and pediatric patients aged 16 years and older with SCD. Adakveo received conditional approval in the European Union in October 2020 for the prevention of recurrent VOCs in SCD patients aged 16 years and older.  Adakveo is administered intravenously and binds to P-selectin, which is a cell adhesion protein that plays a central role in the multicellular interactions that can lead to VOCs.

While these approvals are important milestones for patients with SCD, we believe that there remains a significant unmet need for SCD therapies. Oxbryta was approved by the FDA on an accelerated basis based on improvements in hemoglobin levels as a surrogate endpoint reasonably likely to predict clinical benefit.  Continued approval for this indication may be contingent upon verification and description of the clinical benefit in a confirmatory study which is currently ongoing and is evaluating cerebral blood flow velocity. Adakveo does not treat the underlying cause of SCD and is only available through intravenous administration, not in oral form.

Prior to the approval of Oxbryta and Adakveo for SCD, there were only two FDA-approved drugs in the United States to treat SCD: Hydroxyurea, or HU, and Endari (L-glutamine); and only one approved drug in the European Union:  HU. These therapies have significant limitations in their safety, dosing regimen, efficacy and long-term effects.

HU, an oral chemotherapy that induces HbF and decreases sickling of the RBC, was first approved by the FDA for the treatment of SCD in 1998 and approved in the European Union in 2007. Despite numerous benefits, HU remains a suboptimal therapy for several reasons:

Endari, an oral powder form of L-glutamine, was approved by the FDA in 2017. L-glutamine is an amino acid precursor to nicotinamide adenine dinucleotide, or NAD, and is thought to reduce the oxidative stress that is present in patients with SCD. In September 2019, Emmaus Life Sciences, Inc. withdrew its marketing application to the European Medicines Agency, or EMA, for Endari.

Blood transfusions are another suboptimal treatment option for patients with SCD. Transfusions can transiently bolster hemoglobin levels by adding functional RBCs but can lead to several complications that include iron overload, adverse immune response and transmission of transfusion-associated infections. Due to the lack of uniform accessibility to blood transfusions, they are not widely employed for the treatment of SCD. Allogeneic hematopoietic stem cell transplant, or HSCT, is available as a potentially curative treatment for SCD and acts by halting sickled RBC production from the affected marrow and replacing it with healthy hematopoietic stem cells from a matched donor. HSCT is rarely used due to the difficulty in finding a matched donor, the potential for infection and an approximately 5% mortality rate. The possibility of increased mortality risk relegates this to a last option, often utilized only in the most severe cases.

Due to the limitations of existing therapies, we believe there remains a critical need to develop new preventative therapies that are easy to access, safe for long-term use and address the multiple aspects of SCD pathology.

Emerging Modalities

There has recently been an increased focus on the development of new treatments for SCD with a spectrum of different approaches, but none address the multifactorial pathology of SCD with an oral once-a-day tablet. These approaches can be broadly categorized as follows:

Anti-Polymerization Agents: Anti-polymerization agents, such as Oxbryta, are designed to prevent polymerization of hemoglobin and sickling of RBCs by increasing hemoglobin’s affinity for oxygen and maintaining hemoglobin in an oxygenated state. However, approaches that are solely focused on reducing polymerization may not address the complex symptomology of SCD and the clinical impact of Oxbryta on VOCs remains a question.

HbF Inducers:  HbF inducers seek to reactivate production of HbF in an effort to enhance hemoglobin-oxygen affinity.  Examples include FTX-6058, under development by Fulcrum Therapeutics, Inc., or Fulcrum, and EPI-01, under development by Novo Nordisk A/S, or Novo Nordisk (in collaboration with EpiDestiny, Inc., or EpiDestiny).

PKR Activators:  Pyruvate kinase-R, or PKR, is an enzyme that is involved in the conversion of sugar into energy and is critical for the survival of RBCs. Mutations in PKR cause deficiencies in this process which results in a shortened lifespan for RBCs.  This has led to the hypothesis that PKR activation can overturn this deficiency and may lead to a therapeutic benefit in patients with SCD.  Examples include mitapivat (AG-348), under development by Agios Pharmaceuticals, Inc., or Agios, and etavopivat (FT-4202), which is under development by Forma Therapeutics, Inc., or Forma.  

Selectin Inhibitors: Pan selectin and specific P-selectin inhibitors, such as Adakveo, are designed to reduce adhesion of WBCs to the endothelial cell wall and reduce VOCs; however, selectin inhibitors do not ultimately prevent the sickling of RBCs in SCD. Furthermore, Adakveo requires lengthy infusion treatments every three to four weeks. Global Blood Therapeutics, Inc, or GBT, is also developing inclacumab, a specific P-selectin inhibitor that was previously under development for non-SCD indications.  

Gene Therapy/Editing: Gene-based therapy is an innovative and potentially curative approach to SCD treatment. Like HSCT, gene therapy for SCD involves several pre-treatment steps that can include chemotherapy, which carry significant standalone risks. bluebird bio, Inc., or bluebird, and Aruvant Sciences, Inc., or Aruvant, are each developing gene therapies which aim to deliver a functional copy of the human beta-globin gene.  Gene editing, including CRISPR-Cas9, is an alternative approach to gene modification that has recently advanced in clinical development. Examples of gene editing approaches include CTX-001, currently in development by CRISPR Therapeutics AG, or CRISPR (in collaboration with Vertex Pharmaceuticals Incorporated, or Vertex).  Numerous questions remain with respect to the gene editing approach, including off-target mutagenesis and the ultimate potential reach of such therapeutics. More studies are needed to establish durability and safety of these potential treatments.

The Role of Phosphodiesterase-9 in SCD

Tovinontrine is being developed to inhibit PDE9. PDE9 decreases cGMP, an active signaling molecule that plays an important role in vascular biology. Lower levels of cGMP, as found in patients with SCD, are associated with reduced blood

flow, increased inflammation, greater cell adhesion and reduced nitric oxide-mediated vasodilation.  In addition, PDE9 is highly expressed in cells of interest in SCD, specifically reticulocytes, which are an important cell type for HbF induction. Furthermore, PDE9 has high expression in WBCs and in areas where RBCs are formed.  In preclinical studies, PDE9 inhibitors have been shown to increase cGMP concentrations, induce HbF and F-cells, reduce WBC activation and adhesion across other cell types and modulate adhesion mediators.  This was further demonstrated in preclinical SCD models of tovinontrine, where we observed that tovinontrine is a potent cGMP inducer and had a multimodal mechanism of action, acting to increase HbF expression in RBCs, reduce RBC sickling and decrease expression of WBC adhesion molecules.

Our Solution for Sickle Cell Disease: Tovinontrine as a Differentiated PDE9 Inhibitor

Our approach to address SCD is fundamentally distinct from other therapies. Tovinontrine is being developed to directly and potently inhibit PDE9, which represents a differentiated approach to increase cGMP levels, with a selectivity for PDE9 that we believe will make it amenable for long-term use. We believe tovinontrine may have advantages over other therapies in SCD, including a multimodal approach and an oral, once daily dosing regimen. In addition, tovinontrine tablets have been shown to be stable at high temperatures and in humid conditions, potentially enabling worldwide access, including in areas where SCD and ß-thalassemia are endemic.

We believe tovinontrine has several differentiating features relative to other PDE9 inhibitors:

Highly Potent PDE9 Inhibitor: Tovinontrine is a highly potent PDE9 inhibitor, as measured by induction of cGMP across escalating doses. Tovinontrine has been designed to rapidly increase cGMP, which translates to HbF induction and potentially reduced WBC adhesion.

Differentiated Selectivity and Tolerability Profile: Tovinontrine is highly specific to PDE9 and not selective for other phosphodiesterase family members. Toxicology studies of tovinontrine, including fertility and juvenile studies, support its potential benefit as a long-term therapy in adults and children. We believe this selectivity will allow us to optimize dose while minimizing off-target effects.

Minimal Brain Penetration: Tovinontrine was observed to have minimal brain penetration in preclinical in vivo models relative to other PDE9 inhibitors that have been studied. We believe this will reduce the potential impact of PDE9 inhibition on central nervous system development and function.

Drug Product Stability: Tovinontrine tablets have been shown to be stable at high temperatures and in humid conditions, potentially enabling worldwide access, including in underserved regions where SCD and β-thalassemia are endemic.

Preclinical and Healthy Volunteer Data

In preclinical SCD models, we observed that tovinontrine is a potent cGMP inducer and had a multimodal mechanism of action, acting to increase HbF expression in RBCs, reduce RBC sickling and decrease expression of WBC adhesion molecules.

In an SCD in vitro model, we measured the ability of tovinontrine to increase cGMP levels in an RBC cell line as compared to HU. In this study, we observed that tovinontrine induced cGMP production in a dose-dependent manner at an approximately 30-fold lower drug concentration than HU. In addition, at an equivalent drug concentration of 10 µM of tovinontrine, we observed an approximately ten-fold increase in cGMP levels as compared to HU. We also evaluated tovinontrine in a mouse model of SCD that expresses human sickle hemoglobin. We observed that tovinontrine demonstrated statistically significant increases in F-cells, statistically significant decreases in the percentage of sickled RBCs and decreases in markers of hemolysis, or destruction of RBCs, and WBC adhesion.

In 2016, we initiated a Phase 1 randomized, double-blind, placebo-controlled clinical trial of tovinontrine in healthy volunteers.  In that trial, single and multiple ascending doses of tovinontrine were reported to be well tolerated to a maximum dose of 4.5 mg/kg per day and no serious adverse events were reported.  In 2021, we conducted a second healthy volunteer clinical trial of tovinontrine to explore higher doses of tovinontrine. This single ascending dose followed by a multiple dose trial tested doses of up to 13 mg/kg per day.  The results demonstrated that doses of up to 8 mg/kg per day were well tolerated and no dose limiting toxicities or serious adverse events were reported at any dose tested.

Phase 2a Clinical Trial of Tovinontrine in SCD

Our Phase 2a clinical trial was a randomized, double-blind, placebo-controlled clinical trial in adult patients with SCD and was conducted at clinical centers in the United States and the United Kingdom. The trial evaluated the safety, tolerability, pharmacokinetics, or PK, and exploratory pharmacodynamic, or PD, and clinical outcomes of escalating doses of tovinontrine administered once daily for 16 to 24 weeks, either as a monotherapy or in combination with HU. A total of 93 patients were dosed in the trial, of which 58 patients were on monotherapy and 35 patients were treated in combination with HU.  Patients on treatment in the monotherapy arm received an escalating dose of tovinontrine of up to 200 mg per day, while patients in the combination arm received an escalating dose of tovinontrine of up to 100 mg per day in addition to HU.

The data from the Phase 2a clinical trial demonstrated that tovinontrine was well tolerated as a monotherapy and in combination with HU at all dose levels. Changes in SCD-related biomarkers were variable across the trial. A post-hoc analysis of the pooled results further showed that when compared to placebo (N=30), patients on tovinontrine (N=63) had:

Phase 2a Open Label Extension of Tovinontrine in SCD

We are conducting a four-year OLE clinical trial which allows patients from the Phase 2a clinical trial to enroll in a long-term safety and tolerability study of tovinontrine following completion of the Phase 2a clinical trial.  Patients in the OLE clinical trial initially received a once-daily dose of tovinontrine of 200 mg and have subsequently been escalated to a once-daily dose of up to 400 mg.

In December 2021, we presented 12-month data from the OLE trial at the American Society of Hematology (ASH) Annual Meeting. Of the 26 subjects enrolled, 21 were evaluable at month 12 (as of the data cut-off).  Tovinontrine was generally well-tolerated as a monotherapy as well as in combination with HU. There were no clinically significant changes in lab safety data, electrocardiogram data or vital signs, and no patients discontinued from the study due to adverse events.

The median annualized VOC rate was reduced by 38% in subjects previously in the placebo group in the Phase 2a clinical trial (N=7), with median annualized VOC rates of 5.0 (Phase 2a) and 3.1 (OLE) per year, with a median duration of treatment of 6.4 months and 11.6 months, respectively.

The low median annualized VOC rate for tovinontrine-treated patients in the Phase 2a clinical trial was maintained in subjects in the OLE clinical trial (N=14), with median annualized VOC rates of 0 (Phase 2a) and 2.0 (OLE) per year, with a median duration of treatment of 6.4 months and 11.8 months, respectively.

22% (4/18) of evaluable patients had an absolute increase in HbF greater than 3%. 47% (9/19) of patients had an absolute increase in F-cells greater than 6%, and F-cell increases were observed in 18 out of 19 evaluable patients.

Ardent Phase 2b Clinical Trial of Tovinontrine in SCD

We are currently conducting the Ardent Phase 2b clinical trial of tovinontrine in SCD, a randomized, double-blind, placebo-controlled, multicenter study of approximately 115 adult patients with SCD. Patients were initially randomly assigned in a 2:1 ratio to receive either low dose tovinontrine (once daily dose of 200 mg or 300 mg based on patient weight) or placebo.  In the first quarter of 2021, an independent data monitoring committee for the Ardent trial recommended opening of the high dose tovinontrine treatment arm following review of available safety and tolerability data.  After this point, patients were randomly assigned in a 1:2:1 ratio to receive low dose tovinontrine (once daily dose of 200 mg or 300 mg based on patient weight), high dose tovinontrine (once daily dose of 300 mg or 400 mg based on patient weight) or placebo.  We completed enrollment in the Ardent trial in the third quarter of 2021.

The planned primary efficacy endpoint of the Ardent trial is annualized rate of VOCs, and the trial is powered for statistical significance with respect to this endpoint. We decided to change the primary endpoint of the Ardent trial from HbF response, defined as an increase of ≥3% in HbF, to annualized rate of VOCs following a written recommendation from the FDA in November 2021.  HbF response will continue to be evaluated as one of two key secondary endpoints, with an

evaluation of time to first VOC as the other key secondary endpoint.  In addition, other secondary endpoints include the evaluation of the effect of tovinontrine versus placebo on (i) the percent of patients who are VOC-free, time to second VOC, VOC-related hospitalizations, (ii) HbF-associated biomarkers, (iii) indices of red cell hemolysis, (iv) indices of WBC adhesion, and (v) quality of life measures.

We plan to conduct an interim analysis from the Ardent trial of patients who have reached at least 24 weeks of dosing and expect to report data related to the primary endpoint from this interim analysis in the first week of April 2022.  We expect to report final data from the Ardent trial through 52 weeks of treatment in the second half of 2022.  

In the second quarter of 2022, we expect to initiate long-term OLE clinical trial of tovinontrine for patients who complete the Ardent Phase 2b clinical trial in SCD.  In addition to patients from the Ardent trial, we expect patients from the ongoing Phase 2a OLE trial to roll over into this new OLE trial, resulting in one OLE trial with patients from both the Phase 2a clinical trial and the Ardent Phase 2b clinical trial.

β-thalassemia Disorder Overview

β-thalassemia is a rare inherited RBC disorder. Unlike patients with SCD, patients with β-thalassemia have a mutation that causes the absence or decreased synthesis of the beta globin subunit of hemoglobin, thereby creating an over-abundance of the alpha globin subunit. This causes the formation and aggregation of insoluble clumps that lead to ineffective RBC production and a reduction in the number of functioning RBCs. Furthermore, the RBCs that do survive have shorter lifespans and are smaller, paler and less efficient at transporting oxygen throughout tissues of the body. Oftentimes, RBCs of smaller size, measured as mean corpuscular volume, is a first indication of β-thalassemia prior to genotyping. If left untreated, β-thalassemia causes severe anemia, splenomegaly, skeletal abnormalities, organ failure and early death.

β-thalassemia presents as a spectrum of disease, with patients categorized based on hemoglobin levels and clinical manifestations. Although β-thalassemia can be classified as “major,” “intermedia,” and “minor,” a more recent classification is based on a patient’s dependency on blood transfusion. Most β-thalassemia major patients are classified as TDT, while intermedia and minor patients are classified as NTDT. TDT patients have a transfusion regimen that is well established and generally lifelong. NTDT patients are a clinically diverse group, with transfusions required intermittently during periods of RBC stress, such as pregnancy, infection, surgery, times of rapid growth and sometimes later in life.

As in SCD, a promising way to address the missing or decreased presence of the beta globin subunit is to induce HbF production. In addition to resolving persistent anemia, HbF induction rectifies the missing or mutated beta globin subunit and thereby reduces the overabundance of free-floating alpha globin subunits. These benefits have the potential to result in increased functional RBC production, higher hemoglobin levels, reduced hemolysis and the reduction of adhesion and inflammation. In addition to HbF induction, independent research suggests activation of the nitric oxide-cGMP signaling pathway may induce RBC production, which is associated with increases in RBC counts and hemoglobin levels. We believe this is an important mechanism of action to that could be relevant in reducing disease burden. Furthermore, adhesion mediators are also highly upregulated in patients with β-thalassemia and may contribute to the increased number of clots in their blood vessels, known as a hypercoagulability state. Specifically, data show that two adhesion markers, ICAM-1 and VCAM-1, are over-expressed in patients with β-thalassemia as compared to controls. Furthermore, there is evidence that WBCs in patients with β-thalassemia express higher levels of CD11b and CD18, two important biomarkers in the WBC activation cascade.

Addressable Patient Population

The prevalence of β-thalassemia globally is estimated to be 288,000, with an incidence of 60,000 births per year. The total combined prevalence of β-thalassemia in the United States and European Union is estimated to be approximately 19,000 patients. Of the patients currently treated in the United States and European Union, we believe approximately 50% and 10%, respectively, are transfusion dependent. β-thalassemia is especially prevalent in developing countries of Africa, South Asia, Southeast Asia, the Mediterranean region and the Middle East. Although historically prevalent in Mediterranean North Africa and South Asia, thalassemias are now encountered in other regions as a result of changing migration patterns. As such, there is a growing focus on developing new therapeutics aimed at improving quality of life for this significant unmet medical need.

Approved and Emerging Modalities and Their Limitations

Approved Treatments

Blood transfusions have been the standard of care treatment for β-thalassemia. The risks associated with transfusions are similar to those seen in the SCD population, but higher frequency of use often results in iron overload toxicities, a secondary complication of this treatment. Over time, iron becomes trapped in the tissues of vital organs, which can lead to diabetes, cirrhosis, osteoarthritis, heart attack and hormone imbalances. If not addressed, excess iron can result in organ failure and death. There are several approved agents that remove iron from the body, known as iron chelators, but they have significant challenges including high costs, the requirement for frequent monitoring, therapy complications and patient incompatibility.

HSCT is a potential curative therapy for β-thalassemia and has demonstrated successful outcomes across patient types. However, as in SCD, there are numerous barriers to use, including increased mortality risk, that have limited its broader adoption. Recently, the European Commission granted conditional marketing authorization for ZYNTEGLO,Zynteglo, a gene therapy approach to β-thalassemia for patients 12 years and older with TDT and for whom HSCT is appropriate, but a donor has not yet been matched or been made available. The long-term efficacy of the therapy remains unknown, as do many of the associated risks.

In November 2019, the FDA approved REBLOZYLReblozyl (luspatercept-aamt) for the treatment of anemia in adult patients with β-thalassemia who require regular RBC transfusions. REBLOZYLReblozyl was approved by the European Commission in June 2020 to treat adult patients with transfusion-dependent anemia associated with ß-thalassemia.  Reblozyl is a modified receptor protein that promotes RBC maturation and increases overall RBC production, but does not address other cell types implicated in β-thalassemia. REBLOZYLReblozyl is not indicated for use as a substitute for RBC transfusions in patients who require immediate correction of anemia. REBLOZYLReblozyl is the first and only FDA-approved erythroid maturation agent, representing a new class of therapy which works by regulating late-stage RBC maturation to help patients reduce their RBC transfusion burden.

Emerging Modalities

There has been increased development of new treatments for β-thalassemia, but no clinical-stage program addresses the full spectrum of the disease in an oral, once-a-day tablet. These treatments can be broadly categorized into the following approaches:

RBC Maturation. Maturation: Clinical stage programs in this category generally are aimed at promoting RBC maturation and/or increasing overall RBC production, but do not address other cell types implicated in b-thalassemia. Several molecules targeting this pathway which includes the key regulators hepcidin and ferroportin, are in Phase 2 clinical development in patients with b-thalassemia to treat chronic anemia associated with ineffective erythropoiesis and iron overload.overload are in development. These include IONIS-TMPRss6-LRx, an antisense drug under development by Ionis Pharmaceuticals, andVIT-2763, a ferroportin inhibitorInc., or Ionis Pharmaceuticals, SLN-124, under development by Silence Therapeutics PLC, or Silence Therapeutics, and VIT-2763, under development by Vifor Pharma.Pharma Ltd, or Vifor.

Gene Therapy/Editing: As with SCD, gene therapy and gene editing approaches are also being developed as potential curative therapies for b-thalassemia. Lentiglobinbeti-cel is a gene therapy treatment in Phase 3 clinical development by bluebird, bio, while CTX-001 and ST-400 areis a gene editing therapiestherapy currently in Phase 2 clinical development by CRISPR Therapeutics AG (in collaboration with Vertex Pharmaceuticals, Incorporated) and Sangamo Therapeutics, Inc. (in collaboration with Sanofi), respectively.Vertex). Gene therapy involves pretreatment regimens associated with standalone risk which may limit its use in broad patient populations, and gene editing approaches still have many unanswered questions, including off-target mutagenesis.

PKR Activators.: Drug candidates are being developed that activate PKR, an enzyme that is involved in the conversion of sugar into energy and is critical for the survival of RBCs.  Examples include mitapivat, under development by Agios, Pharmaceuticals, Inc. is evaluating mitapivatand etavopivat, under development by Forma in a Phase 2 clinical trial in non-transfusion-dependentTDT and NTDT patients with ß-thalassemia. Forma Therapeutics has reported that it plans to initiate clinical development of its PKR activator, FT-4202, in patients with ß-thalassemia.

Our Solution for β-thalassemia: IMR-687Tovinontrine as a Differentiated PDE9 Inhibitor

PDE9 is a potent and highly selective mechanism that uniquely targets cyclic GMPcGMP degradation, making it a promising pathway to increase cyclic GMP,cGMP, reactivate HbF, enhance RBC production, enable RBC maturation, and reduce WBC activation in β-thalassemia. We believe IMR-687tovinontrine is a differentiated PDE9 inhibitor that is highly potent, selective for its target, minimally brain penetrating, and is delivered in an oral, once-a-day therapy, which could be used globally.

Preclinical Data of IMR-687Tovinontrine in ß-thalassemia

We conducted preclinical studies in a ß-thalassemia mouse model that recapitulates the human NTDT condition. This mouse model lacks a functional beta globin subunit, leading to deficits in hemoglobin and RBCs, as well as slowed RBC maturation. After 30 days of treatment at two different doses, we observed that IMR-687tovinontrine induced statistically significant increases in functional hemoglobin and total RBC counts in a dose dependent way, with the 60mg/kg dose outperforming the 30mg/kg dose. Allometric scaling to reflect dose conversion from mouse to human indicates that the 30mg/kg mouse dose is equivalent to a human dose of approximately 2.4mg/kg and the 60mg/kg mouse dose is equivalent to a human dose of approximately 4.9mg/kg.

Promotion of RBC maturation, a key mechanistic component in reducing ß-thalassemia pathology, was also observed in preclinical studies. After 30 days of once-a-day treatment with 30 mg/kg and 60 mg/kg of IMR-687,tovinontrine, we observed that erythroblast maturation was significantly improved as a result of increasingreflected by an increase in the amount of Ery.C, which is the population of mature erythroblasts, in comparison to Ery.B, which are more immature erythroblasts. These changes were also associated with a decrease on the ratio of Ery.B to Ery.C, otherwise known as a maturation index, where lower ratio indicates progression to maturity.

We believe the NTDT mouse model provides promising in vivo proof of concept that IMR-687 can improve the RBC-mediated aspects of ß-thalassemia. In addition, we believe the preclinical activity observed in NTDT models will translate to TDT preclinical models and supports clinical development in both populations. While SCD and ß-thalassemia are distinct hemoglobinopathies, they share similar pathophysiology and symptomology which support our strategy of developing IMR-687 across these indications.

Forte Phase 2b Clinical Trial of IMR-687Tovinontrine in ß-thalassemia

InWe are currently conducting the second quarterForte Phase 2b clinical trial of 2020, we initiatedtovinontrine in ß-thalassemia, a randomized, double-blind, placebo-controlled Phase 2b clinical trial, which we refer to as the Forte trial, in adult patients with ß-thalassemia and enrollment is ongoing. The trial will evaluateevaluating the safety and tolerability of IMR-687tovinontrine in approximately 60 TDT120 adult patients with ß-thalassemia.  Similar to the Ardent SCD trial, patients were initially randomly assigned in a 2:1 ratio to receive either low dose tovinontrine (once daily dose of 200 mg or 300 mg based on patient weight) or placebo.  In the first quarter of 2021, an independent data monitoring committee for the Forte trial recommended opening of the high dose tovinontrine treatment arm following review of available safety and approximately 60 NTDT patients. Additionally,tolerability data.  After this point, patients have been randomly assigned in a 1:2:1 ratio to receive low dose tovinontrine (once daily dose of 200 mg or 300 mg based on patient weight), high dose tovinontrine (once daily dose of 300 mg or 400 mg based on patient weight) or placebo.

In addition to safety, for TDT patients, we plan to evaluateare evaluating the effect of IMR-687tovinontrine versus placebo in reducing the average number of days between red blood cell transfusions, or transfusion burden, and changeRBC units transfused in iron load rate as the result of transfusion, for the treatment periodany 12-week interval as compared to the 12 weeks12-week interval prior to screening. Frequent transfusions in TDT patients lead to iron overload, which is a common complication often leading torandomization, known as the development of organ damage and increased mortality in these patients. Accordingly, improvement in iron load rate is an important measure of an effective therapy for TDT patients.transfusion burden. For NTDT patients, we plan to evaluateare evaluating the effect of IMR-687tovinontrine versus placebo on HbF as well as on anemia.and hemoglobin, or Hb. The Forte trial will also examine additional exploratory efficacy endpoints as well as additional safety and PK endpoints.

The Forte trial will consist ofIn November 2021, we conducted a retrospective data collection period, a screening period, a double-blind treatment period and a safety follow-up period. Similar to our Phase 2b trial of IMR-687 for SCD, we plan to utilize weight-based dosing. We believe this use of weight-based dosing will more precisely manage drug exposure and tolerability, so that patients with below average weights do not receive too high of a dose and patients with above average weight do not receive too low of a dose. The lower-dose IMR-687 arm will test a range of 3.0mg/kg up to 4.5mg/kg (including up to a 300 mg dose) and patients will be randomly assigned in a 2:1 ratio to receive either IMR-687 or placebo. The higher-dose IMR-687 arm will test a range of >4.5mg/kg up to 6.7mg/kg (including up to a 400 mg dose). In January 2021, an independent DMC reviewed available safety and tolerability data and recommended inclusion of the higher dose arm.  Going forward, randomization will proceed in a 1:2:1 ratio (IMR-687 lower dose, IMR-687 higher dose, or placebo). Safety and tolerability will be assessed after 24 weeks of dosing. There are pre-specified protocol-driven interim analyses plannedin approximately 43 TDT patients, 35 of whom completed at least 12 weeks of treatment and were in the trial,analysis population for transfusion burden.  The median baseline transfusion burden in each of the high dose tovinontrine and placebo groups was 7.5 RBC units/12 weeks. Furthermore, 54% of the subjects in the analysis population (19/35) had the more severe β⁰/β⁰ genotype.  The interim data demonstrated tovinontrine was well-tolerated, with the first such interim analysismost frequent adverse events (at least 10% of subjects in pooled tovinontrine dose groups) being conductednausea, headache and dizziness. Four (9.3%) patients discontinued due to adverse events considered at least possibly related to study drug.

The proportion of patients who had at least a33% reduction in transfusion burden (of at least 2 units) in any 12-week interval as compared to the 12-week interval prior to randomization was greater in the high dose tovinontrine group (7/8) versus placebo, despite an unexpectedly high response rate in the placebo group (8/12). Additionally, the proportion of patients who had at least a 33% reduction in transfusion burden (of at least 2 units) in any 14-week interval as compared to the 12-week interval prior to randomization was also greater in the high dose tovinontrine group (5/8) versus the placebo group (5/12).  Low dose tovinontrine did not show a higher response rate when 30 patients have reached 24 weeks of dosing and an additional interim analysis being conducted when 30 patients have reached 36 weeks of dosing. compared to the placebo group. No substantial differences between groups were observed in transfusion burden response rate using a fixed interval (weeks 13-24). RBC markers were not evaluable in these regularly transfused subjects.

We expect to report data from an additional interim analysis in approximately 50 TDT patients and 30 NTDT patients through 24 weeks of dosing in the first interim analysisweek of April 2022 and final data from the Forte trial in the second half of 2021.2022.

Preclinical PipelineHFpEF Disease Overview

We are advancing a pipeline of development-stage programs utilizing IMR-687 targeting additional indications, including HFpEF, for which we began preclinical research in the second quarter of 2020. Heart failure affects approximately 26 million people worldwide. HFpEF represents almost half of all cases ofalso known as diastolic heart failure, with approximately 2.5-3 million affected adults in the United States alone. Pathophysiologic characteristicsis typically caused by abnormalities of cardiac filling, which leads to symptoms such as shortness of breath, exercise intolerance and fluid retention. Characteristics of HFpEF are heterogeneous, but commonly include ventricular hypertrophy, diastolic dysfunction, endothelial dysfunction, insulin resistance, and inflammationinflammation. Comorbidities, such as hypertension, anemia, chronic kidney disease, diabetes, and manyobesity, are also common

in HFpEF, which are thought to contribute to its development.  HFpEF accounts for approximately half of these have also been describedall cases of heart failure and is becoming the predominant form of heart failure over time.   Prevalence in SCD. Cyclic GMPthe United States is estimated to be approximately 3-4 million patients.  In contrast to heart failure with reduced ejection fraction, or HFrEF, there are relatively few treatment options to improve symptoms and outcomes for patients.

Our Solution for HFpEF: Tovinontrine as a Differentiated PDE9 Inhibitor

cGMP is known to play a pivotal role in cardiovascular and metabolic health. For example, increased cyclic GMPcGMP signaling promotes vasodilation, natriuresis, diuresis, insulin sensitivity and lipolysis, and can inhibit cardiac hypertrophy, inflammation and adverse platelet-leukocyte-endothelial interactions, the latter of which have also been implicated in SCD.interactions. Therefore, increasing cyclic GMPcGMP by PDE9 inhibition may be an attractive target for the treatment of HFpEF and a natural extension from our lead program in SCD.  To investigate this hypothesis, we leveraged our existing clinical program in SCD and tested IMR-687 in preclinical models of HFpEF.

In October 2020, the results of an exploratory analysis co-led by VUMC on data from the second interim analysis from our Phase 2a clinical trial of IMR-687 in adult patients with SCD were presented.  The exploratory analysis examined the potential of IMR-687 to reduce cardiovascular risk in patients with SCD.  We measured plasma concentrations of NT-proBNP, a well-established biomarker of cardiovascular risk (higher levels associate with greater risk).  We found patients treated with IMR-687 in combination with HU saw a mean decrease in NT-proBNP of 27.3% from baseline over four months.  In contrast, patients on background HU alone saw a mean increase in NT-ProBNP levels of 27% from baseline over four months.  The magnitude of this difference in treatment effect was more pronounced among patients with higher baseline NT-proBNP levels. Specifically, among patients with baseline NT-proBNP values greater than 400 pg/ml, treatment with IMR-687 in combination with HU led to a mean reduction of 67.9% from baseline in NT-proBNP over four months, as compared with a mean increase of 28.0% from baseline in patients who received HU alone. As SCDbelieve tovinontrine is a condition characterized by acutedifferentiated PDE9 inhibitor that is highly potent, selective for its target, minimally brain penetrating, and chronic vasculopathy as well as high cardiovascular morbidity and mortality, this exploratory analysis by VUMC provides exploratory human data supporting our belief that PDE9 inhibition with IMR-687 may serve asis delivered in an attractive target for the prevention and treatmentoral, once-a-day therapy.

Preclinical Data of cardiovascular disease, such as HFpEF.Tovinontrine in HFpEF

To compliment the observed human data, we also entered into an agreement with the Necker Institute of Paris, France in the second quarter of 2020 to conduct We conducted in vivo studies with IMR-687 tovinontrine in three different established mouse models for HFpEF.HFpEF in collaboration with the Necker Institute of Paris, France. In the first model, we tested whether IMR-687 tovinontrine could prevent the development of HFpEF induced by unilateral nephrectomy and six-week continuous infusion of d-aldosterone.  IMR-687 Tovinontrine was administered at doses of 60 mg/kg or 100

mg/kg concurrently with d-aldosterone for six weeks.  The results showed that IMR-687 tovinontrine significantly attenuated the development of cardiac and cardiomyocyte hypertrophy and limited the increase in biomarkers of myocardial inflammation and fibrosis.  Congruent findings were obtained in the second model, in which mice received continuous infusion of angiotensin II for six weeks to produce the HFpEF phenotype.  IMR-687 Tovinontrine was administered at doses of 60 or 100 mg/kg concurrently with angiotensin II infusion for six weeks.  The results showed that IMR-687 tovinontrine attenuated cardiac and cardiomyocyte hypertrophy and limited the increase in biomarkers of myocardial inflammation and fibrosis.  In addition to these two preventive models, a third model was employed to test the therapeutic potential of IMR-687tovinontrine to treat prevalent HFpEF.  In this study, twenty-week-old20 week-old diabetic prone obese mice that previously displayed the HFpEF phenotype were assigned to receive vehicle or IMR-687 tovinontrine at 60- or 100-mg/kg for eight weeks. The mice treated with IMR-687 tovinontrine displayed significantly less cardiomyocyte hypertrophy and lower levels of biomarkers of myocardial inflammation and fibrosis.  In the control arms of all three models, we found increased myocardial transcript levels of PDE9, atrial natriuretic peptide, or ANP, and B-type natriuretic peptide, or BNP, providing possible evidence for HFpEF being a condition of PDE9 excess..  In all three models, we found IMR-687 that tovinontrine significantly reduced PDE9, ANP and BNP transcript levels in a dose-dependent manner.  

Planned Phase 2 Clinical Trial of Tovinontrine in HFpEF

In the second quarter of 2022, we expect to dose the first patient in the SP₉IN Phase 2 clinical trial of tovinontrine in HFpEF.  The SP₉IN trial will be a randomized, placebo-controlled trial of approximately 170 patients 45 years of age or older with enriched PDE9 expression and persistent symptoms of HFpEF.  Patients will receive either tovinontrine (twice daily dose of 300 mg or 400 mg based on patient weight) or placebo for 16 weeks.  The primary endpoint will be the change in NT-proBNP levels, with secondary endpoints that include safety and tolerability as well as quality of life measures such as Kansas City Cardiomyopathy Questionnaire (KCCQ) and New York Heart Association (NYHA) classification. Exploratory measures are expected to include a clinical composite score, 6-minute walk test and evaluation of cardiac structure and function.

IMR-261 (formerly CXA-10)

Overview

We are collaborating with VUMChave commenced research activities for IMR-261 (formerly CXA-10), an oral, clinic-ready activator of Nrf2.  Nrf2 coordinates the expression of antioxidant genes in response to oxidative stress, regulates inflammation, inhibits the NF-kB pathway and have engaged additional key opinion leadershas been shown to increase HbF.  Prior to its acquisition by us, IMR-261 was evaluated by Complexa, Inc. in heart failure, with the aim of developing a Phase 2 protocol with theclinical trials in FSGS and PAH, and independent medical literature suggests potential to establish proof-of-conceptin a broad array of IMR-687 in the treatmentRBC diseases, including disorders of patients with HFpEF. Additionally, wehemoglobin and iron overload diseases.  We have beguninitiated work on drug product manufacturing for IMR-261 as we explore potential clinical development paths in hemoglobinopathies, iron disorders and potentially other areas.

Preclinical Data for IMR-261

We evaluated IMR-261 in preclinical studies using in-vitro cell cultures and in-vivo mouse models of SCD and b-thalassemia. In CD34+ cells from sickle cell and healthy donors, high dose IMR-261 increased HbF expression by approximately 7-fold versus placebo, whereas lower dose IMR-261 increased HbF expression by approximately 4-fold versus placebo. Furthermore, an approximately 3-fold increase in F-cells was seen in both high dose and low dose groups when compared to placebo. In the Townes mouse model of SCD, high dose IMR-261 induced HbF by approximately 2.2-fold when compared to placebo (8.3 ng/ml versus 3.7 ng/ml). In addition, high dose tovinontrine significantly decreased select markers of hemolysis and increased Hb by approximately 1.1 g/dL when compared to placebo (8.7 g/dL versus 7.6 g/dL).

In a new formulationseparate experiment in Townes SCD mice that assessed VOC reduction after administration of IMR-687 that potentially could be usedTNF-alpha, IMR-261 significantly reduced the presence of RBC on occluded vessels when compared to placebo. IMR-261 was also tested in this indication.a mouse model of b-thalassemia (Hbb^th1/th1) and showed significant increases in Hb and improvements in ineffective erythropoiesis at the high dose.

License and Acquisition Agreements

Tovinontrine – Exclusive License Agreementwith Lundbeck

In April 2016, we entered into an agreement, or the Lundbeck Agreement, with H. Lundbeck A/S, or Lundbeck, for a worldwide license under certain patent rights and certain know-how owned or otherwise controlled by Lundbeck within the field of prevention, treatment or diagnosis of hemoglobinopathy disorders and/or other diseases or disorders, including those directlyexcluding diseases or indirectly related to hemoglobinopathies,disorders of the central nervous system, which we refer to as the field. This agreementLundbeck Field. The Lundbeck Agreement was amended in July 2016 and October 2017.

The agreementLundbeck Agreement grants us an exclusive license under the licensed technology, including the right to grant sublicenses with certain restrictions, to research, develop, make, have made, use, sell, have sold, offer to sell, import, export and commercialize any product comprising or containing certain PDE9 inhibitors, in the field.Lundbeck Field. We call such products licensed products.Lundbeck Licensed Products. Subject to certain restrictions, under the agreement, we grant Lundbeck a non-exclusive, irrevocable, perpetual, worldwide, sub-licenseable, and fully paid-up right and license under patent rights we control to the extent necessary for Lundbeck to research, develop, make, have made, use, sell, have sold, offer to sell, import, export and commercialize licensed productsLundbeck Licensed Products outside of the field.Lundbeck Field.

The agreementLundbeck Agreement also grants us a non-exclusive license under the licensed technology to research and develop, and make, have made, use, import and export for purposes of enabling such research and development, enhancements, improvements, modifications or derivatives to licensed products, until but not beyond a specified pre-commercialization developmental stage with respect to each such enhancement, improvement, modification or derivative. We have the right to request that Lundbeck grant us an exclusive development and commercialization license to one or more compounds identified through these activities as a back-up compound.

As partial consideration for the licenses granted under the agreement,Lundbeck Agreement, we issued 167,523an aggregate of 443,271 shares of our common stock to Lundbeck inbetween April 2016. We issued 127,002 shares of our common stock to Lundbeck in December 2016 and 148,746 shares of our common stock in August 2017 as a result of antidilution provisions contained in the exclusive license agreement triggered by subsequent closings of our series A preferred stock financing.2017. We are also obligated to make milestone payments to Lundbeck aggregating up to (i) $23.5 million upon the achievement of specified clinical, regulatory and first commercial sale milestones by any licensed product and (ii) $11.8 million upon the achievement of specified clinical, regulatory and first commercial sale milestones by any Imara product that is or comprises a PDE9 inhibitor but is not a licensed product,Lundbeck Licensed Product, which is referred to as a PDE9 product,Product, if any. We are obligated to pay tiered royalties of low-to-mid single-digit percentages to Lundbeck based on our, and any of our affiliates’ and sublicensees’, net sales of licensed products,Lundbeck Licensed Products, and tiered royalties of low single-digit percentages to Lundbeck based on our, and any of our affiliates’ and sublicensees’, net sales of PDE9 products,Products, if any. The royalties are payable on a product-by-product and country-by-country basis. Our obligation to make royalty payments extends with respect to a licensed productLundbeck Licensed Products in a country until the later of ten years after the first commercial sale of that licensed productLundbeck Licensed Product in that country and the expiration of the last-to-expire valid claim of a patent or patent application licensed from Lundbeck covering the licensed productLundbeck Licensed Product or any constituent licensed compound in that country. Our obligation to make royalty payments extends with respect to a PDE9 productProduct in a country until the ten years

after the first commercial sale of such PDE9 productProduct in that country. To date pursuant to this agreement, we have made cash payments to Lundbeck of $1.8 million consisting of an upfront payment and ongoing milestone payments.

The agreementLundbeck Agreement obligates us to use commercially reasonable efforts to develop, seek regulatory approval for, manufacture, market and otherwise commercialize at least one licensed product, in accordance with a development plan and a development milestone timetable specified in the agreement.Lundbeck Agreement. We have the option to extend the development milestone timetable up to two times by agreeing to additional payment obligations.

Both we and Lundbeck have the right to terminate the agreementLundbeck Agreement if the other party materially breaches the agreementLundbeck Agreement and fails to cure such breach within specified cure periods or in the event the other party undergoes certain bankruptcy events. Lundbeck may terminate the agreementLundbeck Agreement if we or any of our affiliates, sublicensees or subcontractors bring specified patent challenges against Lundbeck or assist others in bringing such a patent challenge against Lundbeck and fail to cease such challenge within a specified period of time. We have the right to terminate the agreementLundbeck Agreement for our convenience at any time on six months’ prior written notice to Lundbeck.

IMR-261 – Asset Purchase Agreement with Complexa (assignment for the benefit of creditors), LLC

In October 2020, we entered into an asset purchase agreement, or the Complexa APA, with Complexa (assignment for the benefit of creditors), LLC, or Complexa ABC, pursuant to which we acquired all of Complexa ABC’s right, title and interest in and to the assets comprising the Nrf2 program, including CXA-10 (subsequently renamed IMR-261), previously held by Complexa, Inc.  Complexa, Inc. had previously assigned all such assets to Complexa ABC pursuant to a general assignment entered into in August 2020 between Complexa, Inc. and Complexa ABC.

As consideration for the assets acquired under the Complexa APA, we made a one-time payment of approximately $0.1 million and agreed to pay up to an additional approximately $3.8 million in milestone payments based on the achievement of specified clinical and commercial sale milestones as set for the in the Complexa APA.   As part of the acquisition, Complexa ABC assigned to us all of its rights under license agreements with The UAB Research Foundation and the University of Pittsburgh, each as discussed below.

IMR-261 – Exclusive License Agreement with UAB Foundation

In October 2020, we took assignment to an exclusive license agreement, or the UAB Agreement, originally entered into between The UAB Research Foundation, or UAB, and Complexa, Inc. in April 2012.  The UAB Agreement grants us an exclusive worldwide license to practice and fully exploit certain patent rights and to make, have made, develop, use, lease, offer to sell, sell, import and export products covered by such patents within the field of human therapeutics and diagnostics.  We call such products UAB Licensed Products.  We have the right to grant sublicenses with certain restrictions, including obtaining the consent of UAB, which consent may not be unreasonably withheld, conditioned or delayed.

We are obligated to make milestone payments to UAB aggregating up to approximately $0.3 million upon the achievement of specified commercial sale milestones by any UAB Licensed Product and to pay a low single-digit percentage royalty to UAB based on our, and any of our affiliates’ and sublicensees’, net sales of UAB Licensed Products, if any, subject to a minimum annual royalty payment specified in the UAB Agreement.  Our obligation to make royalty payments extends with respect to a UAB Licensed Product until the expiration of the last-to-expire valid claim of a patent licensed from UAB covering the UAB Licensed Product.  The patents subject to the license under the UAB Agreement only have valid claims in the United States. The royalties are payable on a product-by-product basis.

The UAB Agreement obligates us to use commercially reasonable efforts to develop, manufacture, commercialize and market at least one UAB Licensed Product, in accordance with a development plan and a development milestone timetable specified in the UAB Agreement.

The UAB Agreement expires based upon the expiration of the last-to-expire valid claim of a patent licensed from UAB.  We have the right to terminate the UAB Agreement for our convenience at any time on 90 days’ prior written notice to UAB.  UAB has the right to terminate the UAB Agreement if, amongst other reasons, we are in material default of the UAB Agreement and fail to cure such breach within specified cure periods or in the event we undergo certain bankruptcy events.

IMR-261 – Non-Exclusive License Agreement with University of Pittsburgh

In October 2020, we took assignment to an exclusive license agreement, or the Original Pittsburgh Agreement, originally entered into between University of Pittsburgh – Of the Commonwealth System of Higher Education, or University

of Pittsburgh, and Complexa, Inc. in August 2014.   The Original Pittsburgh Agreement was terminated in its entirety in November 2020 and in May 2021, we and the University of Pittsburgh entered into a new license agreement, or the New Pittsburgh Agreement, to replace the Original Pittsburgh Agreement.  The New Pittsburgh Agreement was amended in December 2021.

The New Pittsburgh Agreement grants us a non-exclusive worldwide license to make, have made, manufacture, research, develop, use, sell, offer for sale and commercialize certain products covered by certain patents within the field of hemoglobinopathies, red cell anemias and iron disorders.  We call such products Pittsburgh Licensed Products. We have the right to grant sublicenses with certain restrictions, including obtaining the consent of Pittsburgh, which consent may not be unreasonably withheld.

As partial consideration New Pittsburgh Agreement, we made upfront payments aggregating to less than $0.1 million.  We are obligated to make milestone payments to the University of Pittsburgh of up to approximately $0.3 million in the aggregate upon the achievement of specified clinical and commercial sale milestones by any Pittsburgh Licensed Product and to pay a low single-digit percentage royalty to the University of Pittsburgh based on our, and any of our affiliates’ and sublicensees’, net sales of Pittsburgh Licensed Product, if any, subject to a minimum annual royalty payment specified in the New Pittsburgh Agreement.  Our obligation to make royalty payments extends with respect to a Pittsburgh Licensed Products until the expiration of the last-to-expire valid claim of a patent licensed from the University of Pittsburgh covering the Pittsburgh Licensed Product.  The patents subject to the license under the New Pittsburgh Agreement only have valid claims in the United States.

The New Pittsburgh Agreement obligates us to use commercially reasonable efforts to develop and obtain FDA approval for Pittsburgh Licensed Products, in accordance with a development milestone timetable specified in the New Pittsburgh Agreement.

The New Pittsburgh Agreement expires upon the expiration of the last-to-expire valid claim of a patent licensed from the University of Pittsburgh.  We have the right to terminate the New Pittsburgh Agreement for our convenience at any time on 90 days’ prior written notice to the University of Pittsburgh.  The University of Pittsburgh has the right to terminate the New Pittsburgh Agreement if, amongst other reasons, we default in the performance of any of our obligations under the New Pittsburgh Agreement and fail to cure such breach within specified cure periods or in the event we undergo certain bankruptcy events.

Competition

The biopharmaceutical industry is characterized by rapidly advancing technologies, intense competition and strong emphasis on proprietary products. While we believe that our technology, knowledge, experience and scientific resources provide us with competitive advantages, we face potential competition from many sources, including major pharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions and government agencies and public and private research institutions. Any product candidates that we successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future.

Our competitors may have significantly greater financial resources, established presence in the market, expertise in research and development, manufacturing, preclinical and clinical testing, obtaining regulatory approvals and reimbursement and marketing approved products than we do. These competitors may also compete with us in recruiting and retaining qualified scientific, sales, marketing and management personnel, and establishing clinical trial sites and patient registration for clinical trials. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

If our lead product candidate IMR-687,tovinontrine is approved for the indications that we are currently targeting, it will likely compete with the currently marketed drugs and, if approved, the therapies in development discussed below.

Sickle Cell Disease

Approved drug treatments for SCD focus primarily on the management of anemia and reduction of VOCs. Until November 2019, there were only two drug treatments approved in the United States: HU and Endari.Endari; and only one approved drug treatment in the European Union:  HU. HU, marketed under trade names including DROXIADroxia by Bristol-Myers Squibb Company, as well as in generic form, is approved for the treatment of anemia related to SCD, to reduce the frequency of

VOCs and the need for blood transfusions. Endari, marketed by Emmaus Life Sciences, Inc., is an oral powder form of L-glutamine approved to reduce severe complications associated with the disorder.

In November 2019, the FDA granted accelerated approval for Oxbryta (voxelotor) for the treatment of SCD in adultspatients 12 years of age and children 12older and its label was subsequently expanded to include patients four years of age and older. Oxbryta is an oral therapy taken once daily and is the first approved treatment that directly inhibits sickle hemoglobin polymerization. In February 2022, the European Commission approved Oxbryta for the treatment of hemolytic anemia in patients with SCD 12 years of age and older.  In addition, in November 2019, the FDA approved Adakveo (crizanlizumab), to reduce the frequency of VOCs in adult and pediatric patients aged 16 years and older with SCD. Adakveo received conditional approval in the European Union in October 2020 for the prevention of recurrent VOCs in SCD patients aged 16 years and older.  Adakveo is administered intravenously and binds to P-selectin, which is a cell adhesion protein that plays a central role in the multicellular interactions that can lead to vaso-occlusion.

These two recent approvals represent important milestones for patients with SCD. We believe that IMR-687’s differentiated mechanism of action that seeks to increase HbF in patients with SCD, and the association between increases in HbF and reductions in disease risk, have the potential to provide IMR-687, if approved, with competitive advantages over Oxbryta, where the correlation between increases in hemoglobin and disease risk is being tested in a post-approval confirmatory trial, and Adakveo, which is administered intravenously and does not target RBC sickling. Further, IMR-687 acts primarily on red blood cells and has the potential to act on white blood cells, adhesion markers and other cell types that are implicated in SCD. We believe that IMR-687’s multimodal mechanism-of-action has the potential to demonstrate significant benefit to patients with SCD.

Blood transfusions are also used to treat SCD and can transiently bolster hemoglobin levels by adding functional RBCs. There are a number of limitations associated with this therapeutic approach, including limited patient access and serious complications such as iron overload. The only potentially curative treatment currently approved for severe SCD is HSCT. However, this treatment option is not commonly used given the difficulties of finding a suitable matched donor and the risks associated with the treatment, which include an approximately 5% mortality rate. HSCT is more commonly offered to pediatric patients with available sibling-matched donors.

IMR-687Tovinontrine could face competition from a number of different therapeutic approaches in development for patients with SCD. For example, bluebird bio has reported that it plans to submitthere are a biologic license application, or BLA, for LentiGlobin for the treatmentnumber of SCDcompanies in 2022 based on the results of its ongoing Phase 2 clinical trial. Aruvant Sciences, Inc. is developing ARU-1801, a gene therapy treatment in Phase 2 clinical development.  There are also several gene editing approaches to treating SCD under evaluation, including CTX-001, currently in Phase 2 clinical development byfor gene editing/therapy treatments, including bluebird, Aruvant, CRISPR Therapeutics AG (in collaboration with Vertex Pharmaceuticals, Incorporated)Vertex), BIVV-003, currently in Phase 1/2 clinical development by Sangamo Therapeutics, Inc. (in collaboration with Sanofi), and OTQ923, currently in Phase 1/2 clinical development by Intellia Therapeutics, Inc. (in collaboration with Novartis)., Graphite Bio, Inc. and Editas Medicine, Inc. There are also several companies advancing therapeutic approaches under development outside of gene editing/therapy.therapy, including GBT, Agios, Forma, Vifor, Novo Nordisk A/S (in collaboration with EpiDestiny, Inc.) is evaluating EPI-01, a small molecule designed to increase production of HbF, in Phase 1 clinical trials.EpiDestiny), Fulcrum, Therapeutics, Inc. is developing FTX-HbF, a small molecule designed to upregulate HbF. Agios Pharmaceuticals, Inc. is developing the PKR activator mitapivat (AG-348), which is in Phase 1/2 clinical development,CSL Ltd. and Forma Therapeutics, Inc. is developing the PKR activator FT-4202, which is in Phase 3 clinical development. In addition, Syros Pharmaceuticals, Inc., in collaboration with Global Blood Therapeutics, is using its gene control platform to discover and develop product candidates to activate gamma globin expression to induce the production of HbF for the treatment of SCD.Pfizer.

ß-thalassemia

Until November 2019, there were no approved drug therapies for ß-thalassemia in the United States. The current standard of care for many patients with ß-thalassemia has been frequent blood transfusions to manage anemia. A potentially curative therapy for ß-thalassemia is HSCT, which is associated with serious risk and is limited to patients with a suitable donor.

In November 2019, the FDA approved REBLOZYL (luspatercept-aamt)Reblozyl for the treatment of anemia in adult patients with ß-thalassemia who require regular RBC transfusions. REBLOZYLReblozyl was approved by the European Commission in June 2020 to treat adult patients with transfusion-dependent anemia associated with ß-thalassemia. Reblozyl is a modified receptor protein that promotes RBC maturation and increases overall RBC production, but does not address other cell types implicated in ß-thalassemia. REBLOZYLReblozyl is not indicated for use as a substitute for RBC transfusions in patients who require immediate correction of anemia. REBLOZYLReblozyl is dosed subcutaneously and is administered every three weeks in an outpatient setting.

In June 2019, the European Commission granted conditional marketing authorization for ZYNTEGLO,Zynteglo, a gene therapy developed by bluebird bio for the treatment of adult and adolescent patients with transfusion-dependent ß-thalassemia and with certain genotypes. Bluebird bio submitted its rolling BLA to the FDA which it has announced that it plans to complete in 2021.

IMR-687Tovinontrine could face competition from a number of different therapeutic approaches that are in development as a therapeutic option for patients with transfusion-dependentTDT or non-transfusion-dependentNTDT ß-thalassemia.

For example, Ionis Pharmaceuticals and Vifor Pharma have ongoing Phase 2 trials to evaluate therapies targeting RBC maturation (IONIS-TMPRss6-LRx andVIT-2763, respectively). Agios Pharmaceuticals, Inc. is evaluating mitapivat,there are a PKR activator,number of companies in a Phase 2 clinical trial in non-transfusion-dependent patients with ß-thalassemia. Forma Therapeutics has reported that it plans to initiate clinical development of its PKR activator, FT-4202, in patients with ß-thalassemia. Sangamofor gene editing/therapy treatments, including bluebird, CRISPR (in collaboration with Sanofi) is conducting a Phase 1/2 clinical trialVertex) and Ionis Pharmaceuticals. There are also several companies advancing therapeutic approaches outside of ST-400,gene editing/therapy, including Agios, Forma, Silence Therapeutics and Vifor.

HFpEF

In the area of HFpEF, tovinontrine could face competition from Entresto (marketed by Novartis) and Jardiance (marketed by Eli Lilly & Co.) which uses a genome-edited cell therapy approach designedare currently the only FDA-approved therapies for HFpEF.  We are also aware of several drugs approved for other indications that are likely to produce functional RBCs using HbF. CRISPR Therapeutics AG, in collaboration with Vertex, is conducting a Phase 1/2 clinical trial of CTX-001, which uses a gene editing approach to upregulate the expression of HbF, in patients with transfusion-dependent ß-thalassemia. Syros Pharmaceuticals, Inc., in collaboration with Global Blood Therapeutics, is using its gene control platform to identify and develop product candidates to activate gamma globin expression to induce the production of HbFseek near-term marketing approval for the treatment of ß-thalassemia.

We believe that IMR-687’s differentiated mechanism of actionHFpEF including Farxiga (Astra Zeneca, PLC), Invokana (Johnson & Johnson) and oral route of administration have the potential to provide IMR-687, if approved, with competitive advantages over approved therapies for ß-thalassemia, including REBLOZYL.Zynquista (Lexicon Pharmaceuticals, Inc).  In

addition, Bristol-Myers Squibb Co., Cytokinetics, Inc., Acceleron Pharma, Inc., Palatin Technologies, Inc., Cardurion Pharmaceuticals, Inc. and TransThera Biosciences Co., Ltd., among potentially other companies, are also developing therapeutic approaches for patients with HFpEF.

Intellectual Property

We strive to protect and enhance the proprietary technology, inventions and improvements that are commercially important to the development of our business, including by seeking, maintaining and defending patent rights, whether developed internally or licensed from third parties. We also rely on trade secrets, know-how, continuing technological innovation and in-licensing opportunities to develop, strengthen and maintain our proprietary position in our field.

Our future commercial success depends, in part, on our ability to: obtain and maintain patent and other proprietary protection for commercially important technology, inventions and know-how related to our business; defend and enforce in our intellectual property rights, in particular our patent rights; preserve the confidentiality of our trade secrets; and operate without infringing, misappropriating or violating the valid and enforceable patents and proprietary rights of third parties. Our ability to stop third parties from making, using, selling, offering to sell or importing any products we develop may depend on the extent to which we have rights under valid and enforceable patents or trade secrets that cover these activities.

The patent positions of biopharmaceutical companies like ours are generally uncertain and can involve complex legal, scientific and factual issues. We cannot predict whether the patent applications we are currently pursuing will issue as patents in any particular jurisdiction or whether the claims of any issued patents will provide sufficient proprietary protection from competitors. We also cannot ensure that patents will issue with respect to any patent applications that we or our licensors may file in the future, nor can we ensure that any of our owned or licensed patents or future patents will be commercially useful in protecting our product candidates and methods of manufacturing the same. In addition, the coverage claimed in a patent application may be significantly reduced before a patent is issued, and its scope can be reinterpreted and even challenged after issuance. As a result, we cannot guarantee that any products we develop will be protected or remain protectable by enforceable patents. Moreover, any patents that we hold may be challenged, circumvented or invalidated by third parties. See “Risk Factors—Risks Related to Our Intellectual Property” for a more comprehensive description of risks related to our intellectual property.

We generally file patent applications directed to our key programs in an effort to secure our intellectual property positions vis-a-vis these programs.  As of December 31, 2020, we owned, co-owned, or held exclusive license rights to numerous patent and patent applications, including at least six issued or allowed U.S. patents, five U.S. pending non-provisional patent applications, 29 issued or allowed non-U.S. patents, including four European patent applications which have been validated among individual European Patent Convention nations, 76 non-U.S. pending patent applications, and three pending Patent Cooperation Treaty, or PCT, applications.

The intellectual property portfolio for our most advanced program as of December 31, 2020,tovinontrine and IMR-261, is summarized below. Prosecution is a lengthy process, during which the scope of the claims initially submitted for examination by the U.S. Patent and Trademark Office may be significantly narrowed before issuance, if issued at all. We expect this may be the case with respect to some of our pending patent applications referred to below.

IMR-687Tovinontrine (IMR-687)

The patent portfolio for our IMR-687tovinontrine program includes at least six published patent families. As of December 31, 2020,2021, we owned, co-owned, or held exclusive license rights to numerous patent and patent applications, including at least six issued or allowed U.S. patents, fivenine U.S. pending non-provisional patent applications, 2982 issued or allowed non-U.S. patents, including fourfive European patent applications which have been validated among individual European Patent Convention nations, 7695 non-U.S. pending patent applications, and threefour pending Patent Cooperation Treaty, or PCT, applications relating to our IMR-687tovinontrine program. These patents and patent applications comprise the following patent families:

The issued patents include coverage of the IMR-687tovinontrine composition of matter. The issued patents include US 9,643,970 (exclusively licensed to us from Lundbeck A/S), which issued May 2017. This U.S. patent and related international family members are directed to the IMR-687tovinontrine composition of matter, including racemic mixtures. The expected expiry date of US 9,643,970, including 63 days of Patent Term Adjustment, based on a 20-year term, of US 9,643,970, is December 2032, absent any other patent term extensions available.

The issued patents also include US 9,434,733 (exclusively licensed to us from Lundbeck A/S), which issued September 2016. This U.S. patent and related international family members are directed to the alternative PDE9 inhibitor compositions of matter, including racemic mixtures. The expected expiry date, based on a 20-year term of US 9,434,733, is January 2033, absent any patent term extensions available.

The issued patents also include US 10,513,524 (exclusively licensed to us from Lundbeck A/S), which issued December 2019. This U.S. patent and related international family members provide further protection for the IMR-687 tovinontrine

composition of matter, including the enantiomer, in addition to coverage of therapeutic methods of treating sickle cell disease with IMR-687.tovinontrine . The expected expiry date, based on a 20-year term, of US 10,513,524 is July 2036, absent any patent term extensions available.

The pending applications include an additional patent family directed to therapeutic methods with a priority filing date of July 2016. A patent in Morocco has been allowed in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is June 2037, absent any patent term extensions available.

The pending applications also include a patent family directed to process chemistry for manufacturing with a priority date of May 2017. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is May 2038, absent any patent term extensions available.

The PCT applications include a patent family directed to polymorphs of IMR-687tovinontrine with a priority filing date of May 2018. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is May 2039, absent any patent term extensions available.

The pending PCT applications also include a PCT application directed to solid dose formulations of IMR-687tovinontrine with a priority filing date of August 2018. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is August 2039, absent any patent term extensions available.

The pending PCT applications also include a PCT application directed to liquid solution formulations of IMR-687tovinontrine with a priority filing date of April 2019. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is April 2040, absent any patent term extensions available.

The pending PCT applications also include a PCT application directed to therapeutic methods of treating thalassemia with a priority date of May 2019. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is May 2040, absent any patent term extensions available.

While we believe that the specific and generic claims contained in our owned and licensed pending U.S., non-U.S., and PCT applications provide protection for the claimed pharmaceutical compositions and methods of use, third parties may nevertheless challenge such claims.

IMR-261

The patent portfolio for our IMR-261 program includes at least four published patent families.  As of December 31, 2021, we owned, co-owned, or held exclusive license rights to numerous patent and patent applications, including at least seven issued or allowed U.S. patents, one U.S. pending non-provisional patent applications, 20 non-U.S. pending patent applications, and two pending PCT application relating to our IMR-261 program. These patents and patent applications comprise the following patent families:

The issued patents include coverage of the IMR-261 composition of matter. The issued patents include US 8,309,526 (exclusively licensed to us from UAB), which issued November 13, 2012. The expected expiry date of US 8,309,526, based on a 20-year term, is April 2025, absent any other patent term extensions available.

The issued patents also include four patents (US 7,776,916, US 9,522,156, US 9,006,473 and 9,867,795, each exclusively licensed to us from UAB), which issued between August 17, 2010 and January 16, 2018. These U.S. patents provide coverage of therapeutic methods of treating certain inflammatory and vascular diseases, including sickle cell disease, with IMR-261. The expected expiry date of these patents, based on a 20-year term, ranges between April 2025 and March 2027, absent any patent term extensions available.

The pending applications include a patent family directed to therapeutic methods of treating certain diseases, including sickle cell disease, at specified doses, with a priority date of October 2015. No patents covering therapeutic methods of treating sickle cell disease have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is October 2036, absent any patent term extensions available.

The PCT applications include a patent family directed to therapeutic methods of treating certain diseases, including sickle cell disease, at additional specified doses, with a priority filing date of May 2020. No patents have issued in this patent family, and the expected expiry date of this patent family, based on a 20-year term, is May 2041, absent any patent term extensions available.

In addition to the above, we have licensed on a non-exclusive basis from the University of Pittsburgh, rights to U.S. issued patents covering pharmaceutical compositions of nitro oleic acids, including IMR-261.  The expected expiry date of these patents, based on a 20-year term, is in mid-2028, absent any other patent term extensions available.

The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file, the patent term is 20 years from the earliest date of filing a non-provisional patent application.

In the United States, the term of a patent covering an FDA-approved drug may, in certain cases, be eligible for a patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984 as compensation for the loss of patent term during the FDA regulatory review process. The period of extension may be up to five years, but cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval. Only one patent among those eligible for an extension and only those claims covering the approved drug, a method for using it, or a method for manufacturing it may be extended. Similar provisions are available in Europe and in certain other jurisdictions to extend the term of a patent that covers an approved drug. It is possible that issued U.S. patents covering IMR-687tovinontrine may be entitled to patent term extensions. If our use of drug candidates or the drug candidate itself receive FDA approval, we intend to apply for patent term extensions, if available, to extend the term of patents that cover the approved use or drug candidate. We also intend to seek patent term extensions in any jurisdictions where available, however, there is no guarantee that the applicable authorities, including the FDA, will agree with our assessment of whether such extensions should be granted, and even if granted, the length of such extensions.

In addition to patent protection, we rely upon unpatented trade secrets and confidential know-how and continuing technological innovation to develop and maintain our competitive position. However, trade secrets and confidential know-how are difficult to protect. We seek to protect our proprietary information, in part, using confidentiality agreements with any collaborators, scientific advisors, employees and consultants and invention assignment agreements with our employees. We also have agreements requiring assignment of inventions with selected consultants, scientific advisors and collaborators. These agreements may not provide meaningful protection. These agreements may also be breached, and we may not have an adequate remedy for any such breach. In addition, our trade secrets and/or confidential know-how may become known or be

independently developed by a third party, or misused by any collaborator to whom we disclose such information. Despite any measures taken to protect our intellectual property, unauthorized parties may attempt to copy aspects of our products or to obtain or use information that we regard as proprietary. Although we take steps to protect our proprietary information, third parties may independently develop the same or similar proprietary information or may otherwise gain access to our proprietary information. As a result, we may be unable to meaningfully protect our trade secrets and proprietary information. See “Risk Factors—Risks Related to Our Intellectual Property” for a more comprehensive description of risks related to our intellectual property.

Manufacturing

We currently contract with third parties for the manufacture of our product candidates for preclinical studies and clinical trials and intend to do so in the future. We do not own or operate manufacturing facilities for the production of clinical or commercial quantities of our product candidates. We currently have no plans to build our own clinical or commercial scale manufacturing capabilities. To date, our third-party manufacturers have met our manufacturing requirements. We expect third-party manufacturers to be capable of providing sufficient quantities of our program materials to meet anticipated clinical-trial scale demands. To meet our projected needs for commercial manufacturing, third parties with whom we currently work will need to increase their scale of production or we will need to secure alternate suppliers. We believe that there are alternate sources of supply that can satisfy our clinical and commercial requirements, although we cannot be certain that identifying and establishing relationships with such sources, if necessary, would not result in significant delay or material additional costs. Although we rely on contract manufacturers, we have personnel with manufacturing experience to oversee our relationships with contract manufacturers.

Sales and Marketing

In light of our stage of development, we have not yet established a commercial organization or distribution capabilities. We have retained worldwide commercial rights for our product candidates. If our product candidates receive marketing approval, we plan to commercialize them in the United States and Europe and potentially other international regions with our own sales force.

Government Regulation and Product Approvals

Government authorities in the United States at the federal, state and local level, and in other countries and jurisdictions, such as the European Union, or EU, extensively regulate, among other things, the research, development, testing, manufacture, pricing, quality control, approval, packaging, storage, recordkeeping, labeling, advertising, promotion, distribution, marketing, post-approval monitoring and reporting, and import and export of biopharmaceutical products. The processes for obtaining marketing approvals in the United States and in foreign countries and jurisdictions, along with compliance with applicable statutes and regulations and other regulatory authorities, require the expenditure of substantial time and financial resources.

Approval and Regulation of Drugs in the United States

In the United States, drug products are approved and regulated under the Federal Food, Drug and Cosmetic Act, or FDCA, and applicable implementing regulations and guidance. A company, institution or organization that takes responsibility for the initiation and management of a clinical development program for such products, and for their regulatory approval, is typically referred to as a sponsor.  The failure of an applicanta sponsor to comply with the applicable regulatory requirements at any time during the product development process may result in delays to the conduct of a study, regulatory review and approval and/or administrative or judicial sanctions.

An applicantA sponsor seeking approval to market and distribute a new drug in the United States generally must satisfactorily complete each of the following steps before the product candidate will be approved by the FDA:

Preclinical Studies

Before an applicanta sponsor begins testing a product candidate with potential therapeutic value in humans, the product candidate enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, formulation and stability, as well as other studies to evaluate, among other things, the toxicity of the product candidate. The conduct of the preclinical tests and formulation of the compounds for testing must comply with federal regulations and requirements, including GLP regulations and standards.standards and the United States Department of Agriculture’s Animal Welfare Act, if applicable. Some long-term preclinical testing, such as animal tests of reproductive adverse events and carcinogenicity and long-term toxicity studies may continue after the IND is submitted.

The IND and IRB Processes

An IND is a request for FDA authorization to administer such investigational product to humans. Such authorization must be secured prior to interstate shipment and administration of any product candidate that is not the subject of an approved NDA. In support of a request for an IND, applicantssponsors must submit a protocol for the clinical trial, and any subsequent protocol amendments must be submitted to the FDA as part of the IND application. In addition, the results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and plans for clinical trials, among other things, must be submitted to the FDA as part of an IND. The FDA requires a 30-day waiting period after the filing of each IND before clinical trials may begin. This waiting period is designed to allow the FDA to review the IND to determine whether human research subjects will be exposed to unreasonable health risks. At any time during this 30- day period, the FDA may raise concerns or questions about the conduct of the trials as outlined in the IND and impose a clinical hold or partial clinical hold. In this case, the IND sponsor and the FDA must resolve any outstanding concerns before clinical trials can begin.

Following commencement of a clinical trial under an IND, the FDA may also place a clinical hold or partial clinical hold on that trial. A clinical hold is an order issued by the FDA to the sponsor to delay a proposed clinical investigation or to suspend an ongoing investigation. A partial clinical hold is a delay or suspension of only part of the clinical work requested under the IND. For example, a specific protocol or part of a protocol is not allowed to proceed, while other protocols may do so. No more than 30 days after imposition of a clinical hold or partial clinical hold, the FDA will provide the sponsor a written explanation of the basis for the hold. Following issuance of a clinical hold or partial clinical hold, an investigation may only resume after the FDA has so notified the sponsor that the investigation may proceed. The FDA will base that determination on information provided by the sponsor correcting the deficiencies previously cited or otherwise satisfying the FDA that the investigation can proceed.

A sponsor may choose, but is not required, to conduct a foreign clinical study under an IND. When a foreign clinical study is conducted under an IND, all FDA IND requirements must be met unless waived. When a foreign clinical study is not conducted under an IND, the sponsor must ensure that the study complies with certain regulatory requirements of the FDA in order to use the study as support for an IND or application for marketing approval. The FDA’s regulations are intended to help ensure the protection of human subjects enrolled in non-IND foreign clinical studies, as well as the quality and integrity of the resulting data. They further help ensure that non-IND foreign studies are conducted in a manner comparable to that required for IND studies.

In addition to the foregoing IND requirements, an IRB representing each institution participating in the clinical trial must review and approve the plan for any clinical trial before it commences at that institution, and the IRB must conduct continuing review and reapprove the study at least annually. The IRB must review and approve, among other things, the study protocol and informed consent information to be provided to study subjects. An IRB must operate in compliance with FDA regulations. An IRB can suspend or terminate approval of a clinical trial at its institution, or an institution it represents, if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the product candidate has been associated with unexpected serious harm to patients.

Additionally, some trials are overseen by an independent group of qualified experts organized by the trial sponsor, known as a data safety monitoring board or committee, or DSMB. This group provides a recommendation as to whether or not a trial may move forward at designated check points based on access that only the group maintains to available data from the study. Suspension or termination of development during any phase of clinical trials can occur if it is determined that the participants or patients are being exposed to an unacceptable health risk. Other reasons for suspension or termination may be made by us based on evolving business objectives and/or the competitive climate.

Information about clinical trials must be submitted within specific timeframes to the National Institutes of Health, or NIH, for public dissemination on its ClinicalTrials.gov website.

Expanded Access to an Investigational Drug for Treatment Use

Expanded access, sometimes called “compassionate use,” is the use of investigational new drug products outside of clinical trials to treat patients with serious or immediately life-threatening diseases or conditions when there are no comparable or satisfactory alternative treatment options. The rules and regulations related to expanded access are intended to improve access to investigational drugs for patients who may benefit from investigational therapies. FDA regulations allow access to investigational drugs under an IND by the company or the treating physician for treatment purposes on a case-by-case basis for: individual patients (single-patient IND applications for treatment in emergency settings and non-emergency settings); intermediate-size patient populations; and larger populations for use of the drug under a treatment protocol or Treatment IND Application.

When considering an IND application for expanded access to an investigational product with the purpose of treating a patient or a group of patients, the sponsor and treating physicians or investigators will determine suitability when all of the following criteria apply: patient(s) have a serious or immediately life-threatening disease or condition, and there is no comparable or satisfactory alternative therapy to diagnose, monitor, or treat the disease or condition; the potential patient benefit justifies the potential risks of the treatment and the potential risks are not unreasonable in the context or condition to be treated; and the expanded use of the investigational drug for the requested treatment will not interfere with the initiation, conduct, or completion of clinical investigations that could support marketing approval of the product or otherwise compromise the potential development of the product. Sponsors of one or more investigational drugs for the treatment of a serious disease(s) or condition(s) must make publicly available their policy for evaluating and responding to requests for expanded access for individual patients.

There is no obligation for a sponsor to make its drug products available for expanded access; however, as required by the 21st Century Cures Act, or Cures Act, passed in 2016, if a sponsor has a policy regarding how it responds to expanded access requests, it must make that policy publicly available. Sponsors are required to make such policies publicly available upon the earlier of initiation of a Phase 2 or Phase 3 trial; or 15 days after the investigational drug or biologic receives designation as a breakthrough therapy, fast-track product, or regenerative medicine advanced therapy.

In addition, on May 30, 2018, the Right to Try Act, was signed into law. The law, among other things, provides a federal framework for certain patients to access certain investigational new drug products that have completed a Phase I clinical trial and that are undergoing investigation for FDA approval. Under certain circumstances, eligible patients can seek treatment without enrolling in clinical trials and without obtaining FDA permission under the FDA expanded access program. There is no obligation for a drug manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act, but the manufacturer must develop an internal policy and respond to patient requests according to that policy.

Human Clinical Trials in Support of an NDA

Clinical trials involve the administration of the investigational product candidate to human subjects under the supervision of a qualified investigator in accordance with GCP requirements, which include, among other things, the requirement that all research subjects provide their informed consent in writing before their participation in any clinical trial. Clinical trials are conducted under written clinical trial protocols detailing, among other things, the objectives of the study, inclusion and exclusion criteria, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated.

Human clinical trials are typically conducted in three sequential phases, but the phases may overlap or be combined. Additional studies may also be required after approval.

Phase 1 clinical trials are initially conducted in a limited population to test the product candidate for safety, including adverse effects, dose tolerance, absorption, metabolism, distribution, excretion and pharmacodynamics in healthy humans or in patients. During Phase 1 clinical trials, information about the investigational drug product’s pharmacokinetics and pharmacological effects may be obtained to permit the design of well-controlled and scientifically valid Phase 2 clinical trials.

Phase 2 clinical trials are generally conducted in a limited patient population to identify possible adverse effects and safety risks, evaluate the efficacy of the product candidate for specific targeted indications and determine dose tolerance and optimal dosage and dosage schedule. Multiple Phase 2 clinical trials may be conducted by the sponsor to obtain information prior to beginning larger and more costly Phase 3 clinical trials. Phase 2 clinical trials are well controlled, closely monitored and conducted in a limited patient population.

Phase 3 clinical trials proceed if the Phase 2 clinical trials demonstrate that a dose range of the product candidate is potentially effective and has an acceptable safety profile. Phase 3 clinical trials are undertaken within an expanded patient population to further evaluate dosage, provide substantial evidence of clinical efficacy and further test for safety in an expanded and diverse patient population at multiple, geographically dispersed clinical trial sites. A well-controlled, statistically robust Phase 3 clinical trial may be designed to deliver the data that regulatory authorities will use to decide whether or not to approve, and, if approved, how to appropriately label a drug. Such Phase 3 studies are referred to as “pivotal.”

In some cases, the FDA may approve an NDA for a product candidate but require the sponsor to conduct additional clinical trials to further assess the product candidate’s safety and effectiveness after approval. Such post-approval trials are typically referred to as Phase 4 clinical trials and are conducted either as post-marketing commitments or post-marketing requirements. These studies are used to gain additional experience from the treatment of a larger number of patients in the intended treatment group and to confirm a clinical benefit in the case of drugs approved under accelerated approval regulations. Failure to exhibit due diligence with regard to fulfilling post-marketing commitments or post-marketing requirements could result in withdrawal of approval for products.

A clinical trial may combine the elements of more than one phase and the FDA often requires more than one Phase 3 trial to support marketing approval of a product candidate. A company’s designation of a clinical trial as being of a particular phase is not necessarily indicative that the trial will be sufficient to satisfy the FDA requirements of that phase because this determination cannot be made until the protocol and data have been submitted to and reviewed by the FDA. Generally, pivotal trials are Phase 3 trials, but they may be Phase 2 trials if the design provides a well-controlled and reliable assessment of clinical benefit, particularly in an area of unmet medical need.

Progress reports detailing the status and a brief description of available results of the clinical trials must be submitted at least annually to the FDA. In addition, IND safety reports must be submitted to the FDA for any of the following: serious and unexpected suspected adverse reactions; findings from other studies or animal or in vitro testing that suggest a significant risk in humans exposed to the product; and any clinically important increase in the case of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The FDA will typically inspect one or more clinical sites to assure compliance with GCP and the integrity of the clinical data submitted.

Finally, sponsors of clinical trials are required to register and disclose certain clinical trial information on a public registry (clinicaltrials.gov) maintained by the U.S. National Institutes of Health, or NIH. In particular, 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. Both the NIH and the FDA have recently signaled the government’s willingness to begin enforcing those requirements against non-compliant clinical trial sponsors.  The failure to submit clinical trial information to clinicaltrials.gov, as required, is a prohibited act under the FDCA with violations subject to potential civil monetary penalties of up to $10,000 for each day the violation continues.

Concurrent with clinical trials, companies often complete additional animal studies and they must also develop additional information about the chemistry and physical characteristics of the investigational drug as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, must develop methods for testing the identity, strength, quality, purity, and potency of the final drug. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

Pediatric Studies

Under the Pediatric Research Equity Act of 2003, or PREA, an NDA or supplement thereto must contain data that are adequate to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. Sponsors must also submit pediatric study plans prior to the assessment data. Those plans must contain an outline of the proposed pediatric study or studies the applicantsponsor plans to conduct, including study objectives and design, any deferral or waiver requests and other information required by regulation. The applicant,sponsor, the FDA, and the FDA’s internal review committee must then review the information submitted, consult with each other and agree upon a final plan. The FDA or the applicantsponsor may request an amendment to the plan at any time.

For drugs intended to treat a serious or life-threatening disease or condition, the FDA must, upon the request of an applicant,a sponsor, meet to discuss preparation of the initial pediatric study plan or to discuss deferral or waiver of pediatric assessments. In addition, the FDA will meet early in the development process to discuss pediatric study plans with sponsors,

and the FDA must meet with sponsors by no later than the end-of-phase 1 meeting for serious or life-threatening diseases and by no later than ninety (90) days after the FDA’s receipt of the study plan.

The FDA may, on its own initiative or at the request of the applicant,sponsor, grant deferrals for submission of some or all pediatric data until after approval of the product for use in adults, or full or partial waivers from the pediatric data requirements. Additional requirements and procedures relating toA deferral requests and requestsmay be granted for extension of deferralsseveral reasons, including a finding that the product or therapeutic candidate is ready for approval for use in adults before pediatric trials are contained in the Food and Drug Administration Safety and Innovation Act, or FDASIA, in 2012.complete. Unless otherwise required by regulation, the pediatric data requirements do not apply to products with orphan designation.designation, although the FDA has recently taken steps to limit what it considers abuse of this statutory exemption in the PREA.

Rare Pediatric Disease Priority Review Voucher Program

With enactment of the FDASIAFood and Drug Administration Safety and Innovation Act in 2012, and subsequent passage of the Advancing Hope Act of 2016, Congress authorized the FDA to award priority review vouchers to sponsors of certain rare pediatric disease product applications that meet the criteria specified in the law. This provision is designed to encourage development of new drug and biological products for prevention and treatment of certain rare pediatric diseases. Specifically, under this program, a sponsor who receives an approval for a drug or biologic for a “rare pediatric disease” may qualify for a voucher that can be redeemed to receive a priority review of a subsequent marketing application for a different product. The sponsor of a rare pediatric disease drug product receiving a priority review voucher may transfer (including by sale) the voucher to another sponsor. The voucher may be further transferred any number of times before the voucher is used, as long as the sponsor making the transfer has not yet submitted the application.

For the purposes of this program, a “rare pediatric disease” is a (a) serious or life-threatening disease in which the serious or life-threatening manifestations primarily affect individuals aged from birth to 18 years, including age groups often called neonates, infants, children, and adolescents; and (b) rare disease or conditions within the meaning of the Orphan Drug Act. A sponsor may choose to request rare pediatric disease designation, but the designation process is entirely voluntary; requesting designation is not a prerequisite to requesting or receiving a priority review voucher. In addition, sponsors who choose not to submit a rare pediatric disease designation request may nonetheless receive a priority review voucher if they request such a voucher in their original marketing application and meet all of the eligibility criteria.

In December 2016, the 21st Century Cures Act extended the Rare Pediatric Disease Priority Review Voucher Program, authorizing the FDA to award vouchers through September 30, 2022, limited to drugs with rare pediatric disease designation granted by September 30, 2020. On September 30, 2020, Congress provided a short-term extension of the Priority Review Voucher Program. On December 27, 2020, the Rare Pediatric Disease Priority Review Voucher Program was further extended. Under the current statutory sunset provisions, after September 30, 2024, the FDA may only award a voucher for an approved rare pediatric disease product application if the sponsor has rare pediatric disease designation for the drug, and that designation was granted by September 30, 2024. After September 30, 2026, the FDA may not award any rare pediatric disease priority review vouchers.

ReviewSubmission and ApprovalFiling of an NDA

In order to obtain approval to market a drug product in the United States, a marketing application must be submitted to the FDA that provides sufficient data establishing the safety, purity and potency of the proposed drug product for its intended indication. The application includes all relevant data available from pertinent preclinical and clinical trials, together with detailed information relating to the product’s chemistry, manufacturing, controls and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of a use of a product, or from a number of alternative sources, including studies initiated by independent investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety, purity and potency of the drug product to the satisfaction of the FDA.

The NDA is a vehicle through which applicantssponsors formally propose that the FDA approve a new product for marketing and sale in the United States for one or more indications. Every new drug product candidate must be the subject of an approved NDA before it may be commercialized in the United States. Under federal law, the submission of most NDAs is subject to an application user fee, which for federal fiscal year 20212022 is $2,875,842$3,117,218 for an application requiring clinical data. The sponsor of an approved NDA is also subject to an annual program fee, which for federal fiscal year 20212022 is $336,432.$369,413. Certain exceptions and waivers are available for some of these fees, such as an exception from the application fee for products with orphan designation and a waiver for certain small businesses.

Following submission of an NDA, the FDA conducts a preliminary review of the application generally within 60 calendar days of its receipt and strives tomust inform the sponsor within 74 days of the FDA’s receipt of the submissionat that time or before whether thean application is sufficiently complete to permit substantive review. If the FDA determines that the application is incomplete, it will issue a Refuse to File, or RFT, letter and may request additional information rather than accept the application for filing.and studies. In this event, the application

must be resubmitted with the additional information. The resubmitted applicationinformation and is also subject to review before the FDA accepts it for filing.

Once the submission is accepted for filing, the FDA begins an in-depth substantive review. The FDA has agreed to specified performance goals in the review process of NDAs but the review process and the Prescription Drug User Fee Act, or PDUFA, goal date may be extended by the FDA for three additional months to consider new information or clarification provided by the applicantsponsor to address an outstanding deficiency identified by the FDA following the original submission. Under that agreement, 90% of applications seeking approval of New Molecular Entities, or NMEs, are meant to be reviewed within 10 months from the date on which the FDA accepts the application for filing, and 90% of applications for NMEs that have been designated for “priority review” are meant to be reviewed within six months of the filing date.

Before approvingIn connection with its review of an application, the FDA typically will inspect the facility or facilities where the product is or will be manufactured. These pre-approval inspections may cover all facilities associated with an NDA submission, including component manufacturing, finished product manufacturing and control testing laboratories. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving an NDA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP.GCP and the integrity of the data supporting the application.

In addition, as a condition of approval, the FDA may require an applicanta sponsor to develop a REMS. A REMS uses risk-minimization strategies beyond the professional labeling to ensure that the benefits of the product outweigh the potential risks. To determine whether a REMS is needed, the FDA will consider the size of the population likely to use the product, the seriousness of the disease, the expected benefit of the product, the expected duration of treatment, the seriousness of known or potential adverse events and whether the product is a new molecular entity.

The FDA may refer an application for a novel product to an advisory committee or explain why such referral was not made. 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 recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Fast Track, Breakthrough Therapy, Priority Review and Regenerative Advanced Therapy Designations

The FDA is authorized to designate certain products for expedited 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 are referred to as Fast Track designation, Breakthrough Therapy designation, Priority Review designation and Regenerative Advanced Therapy designation. None of these expedited programs change the standards for approval but they may help expedite the development or approval process of product candidates.

Specifically, the FDA may designate a new product for Fast Track review if it is intended for the treatment of a serious or life-threatening disease or condition and it demonstrates the potential to address unmet medical needs for such a disease or condition. For Fast Track products, sponsors may have greater interaction with the FDA, and the FDA may initiate review of sections of a Fast Track product’s NDA before the application is complete. This rolling review may be available if the FDA determines, after preliminary evaluation of clinical data submitted by the sponsor, that a Fast Track product may be effective. The sponsor must also provide, and the FDA must approve, a schedule for the submission of the remaining information, and the sponsor must pay applicable user fees. However, the FDA’s time-period goal for reviewing a Fast Track application does not begin until the last section of the application is submitted. In addition, the Fast Track designation may be withdrawn by the FDA if the FDA believes that the designation is no longer supported by data emerging in the clinical trial process.

Second, a new product may be designated as a Breakthrough Therapy if it is intended to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the product may demonstrate substantial improvement over available therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The FDA may take certain actions with respect to Breakthrough Therapies, including holding meetings with the sponsor throughout the development process; providing timely advice to the product sponsor

regarding development and approval; involving more senior staff in the review process; assigning a cross-disciplinary project lead for the review team and taking other steps to design the clinical trials in an efficient manner.

Third, the FDA may designate a product for Priority Review if it treats a serious condition and, if approved, would provide a significant improvement in safety or effectiveness. The FDA determines, on a case-by-case basis, whether the proposed product represents a significant improvement 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 product reaction, documented enhancement of patient compliance that may lead to improvement in serious outcomes, and 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.

With passage of the 21st Century Cures Act, or the Cures Act in December 2016, Congress authorized the FDA to accelerate review and approval of products designated as Regenerative Advanced Therapies. A product is eligible for this designation if it is a regenerative medicine therapy that is intended to treat, modify, reverse or cure a serious or life-threatening disease or condition and if preliminary clinical evidence indicates that the product has the potential to address unmet medical needs for such disease or condition. The benefits of a Regenerative Advanced Therapy designation include early interactions with the FDA to expedite development and review, benefits available to breakthrough therapies, potential eligibility for Priority Review and accelerated approval based on surrogate or intermediate endpoints.

Accelerated Approval Pathway

The FDA may grant accelerated approval to a product for a serious or life-threatening condition that provides meaningful therapeutic advantage to patients over existing treatments based upon a determination that the 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 condition 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, 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. Products 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 where 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 clinical benefit of a product.

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 product, even if the effect on the surrogate or intermediate clinical endpoint occurs rapidly. Thus, accelerated approval has been used extensively in the development and approval of products 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 trials to demonstrate a clinical or survival benefit. Thus the benefit of accelerated approval derives from the potential to receive approval based on surrogate endpoints sooner than possible for trials with clinical or survival endpoints, rather than deriving from any explicit shortening of the FDA approval timeline, as is the case with priority review.

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 product’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 confirm the effect on the clinical endpoint. Failure to conduct required post-approval studies, or to confirm a clinical benefit during post-marketing studies, would allow the FDA to initiate expedited proceedings to withdraw approval of the product. All promotional materials for product candidates approved under accelerated regulations are subject to prior review by the FDA.

The FDA’s Decision on an NDA

On the basis of the FDA’s evaluation ofAfter evaluating the application and accompanyingall related information, including the resultsadvisory committee recommendations, if any, and inspection reports of the inspection of the manufacturing facilities and clinical trial sites, the FDA maywill issue either a Complete Response Letter, or CRL, or an approval letter or a complete response letter.  An approval letter authorizes commercial marketingTo reach this determination, the FDA must determine that there is substantial evidence that the drug product is effective and that its expected benefits outweigh its potential risks to patients. This “benefit-risk” assessment is informed by the extensive body of evidence about the product with specific prescribing information for specific indications. product’s safety and efficacy in the NDA.

A complete response letterCRL generally outlines the deficiencies in the submission and may require substantial additional testing or information in order for the FDA to reconsider the application. If and when those deficiencies have been addressed to the FDA’s satisfaction in a resubmission of the NDA, the FDA will issue an approval letter. The FDA has committed to reviewing such resubmissions in 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 a CRL is issued, the sponsor will have one year to respond to the deficiencies identified by the FDA, approves a newat which time the FDA can deem the application withdrawn or, in its discretion, grant the sponsor an additional six month extension to respond.

An approval letter authorizes commercial marketing of the product itwith specific prescribing information for specific indications. It may limit the approved indications for use of the product. The agency may also require testing and surveillance programs to monitor the product after commercialization, or impose other conditions, including distribution restrictions or other risk management mechanisms, including a REMS, to help ensure that the benefits of the product outweigh the potential risks. REMS can include medication guides, communication plans for health care professionals, and elements to assure safe use, or ETASU. ETASU can include, but are not limited to, special training or certification for prescribing or dispensing, dispensing only under certain circumstances, special monitoring and the use of patent registries. The FDA may prevent or limit further marketing of a product based on the results of post-market studies or surveillance programs. After approval, many types of changes to the approved product, such as adding new indications, changes and additional labeling claims, are subject to further testing requirements and FDA review and approval.

Post-Approval Regulation

If regulatory approval for marketing of a product or new indication for an existing product is obtained, the sponsor will be required to comply with all regular post-approval regulatory requirements as well as any post-approval requirements that the FDA may have imposed as part of the approval process. The sponsor will be required to report, among other things, certain adverse reactions and manufacturing problems to the FDA, provide updated safety and efficacy information and comply with requirements concerning advertising and promotional labeling requirements. Manufacturers and certain of their subcontractors are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with ongoing regulatory requirements, including cGMP regulations, which impose certain procedural and documentation requirements upon manufacturers.

A product may also be subject to official lot release, meaning that the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. If the product is subject to official release, the manufacturer must submit to the FDA samples of each lot, together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot. The FDA may also perform certain confirmatory tests on lots of some products before releasing the lots for distribution. Finally, the FDA will conduct laboratory research related to the safety, purity, potency and effectiveness of pharmaceutical products.

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

The FDA strictly regulates the marketing, labeling, advertising and promotion of prescription drug products placed on the market. This regulation includes, among other things, standards and regulations for direct-to-consumer advertising, communications regarding unapproved uses, industry-sponsored scientific and educational activities, and promotional activities involving the Internet and social media. Promotional claims about a drug’s safety or effectiveness are prohibited before the drug is approved. After approval, a drug product generally may not be promoted for uses that are not approved by the FDA, as reflected in the product’s prescribing information. In the United States, health care professionals are generally permitted to prescribe drugs for such uses not described in the drug’s labeling, known as off-label uses, because the FDA does not regulate the practice of medicine. However, FDA regulations impose rigorous restrictions on manufacturers’ communications, prohibiting the promotion of off-label uses. It may be permissible, under very specific, narrow conditions, for a manufacturer to engage in nonpromotional, non-misleading communication regarding off-label information, such as distributing scientific or medical journal information as part of bona fide scientific exchange. In September 2021, the FDA published final regulations which describe the types of evidence that the agency will consider in determining the intended use of a drug product.

If a company is found to have promoted off-label uses, it may become subject to adverse public relations and administrative and judicial enforcement by the FDA, the Department of Justice, or the Office of the Inspector General of the Department of Health and Human Services, or HHS, as well as state authorities. This could subject a company to a range of penalties that could have a significant commercial impact, including civil and criminal fines and agreements that materially restrict the manner in which a company promotes or distributes drug products. The federal government has levied large civil and criminal fines against companies for alleged improper promotion, and has also requested that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed.

Pediatric Exclusivity

The Best Pharmaceuticals for Children Act provides an incentive of additional marketing exclusivity in the United States to sponsors who voluntarily complete certain pediatric clinical studies. If granted, pediatric exclusivity provides for the attachment of an additional six months of marketing protectionregulatory exclusivity to the term of any patent or existing regulatory exclusivity, including the non-patent and orphan drug exclusivity. This six-month exclusivity may be granted if an NDA sponsor submits pediatric data that fairly respond to a pediatric written request from the FDA for such data. 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.

Orphan Drug Designation and Exclusivity

Under the Orphan Drug Act, the FDA may designate a drug product as an “orphan drug” if it is intended to treat a rare disease or condition, generally meaning that it affects fewer than 200,000 individuals in the United States, or more in cases in which there is no reasonable expectation that the cost of developing and making a product available in the United States for treatment of the disease or condition will be recovered from sales of the product. A company must seek orphan drug designation before submitting an NDA for the candidate product. If the request is granted, the FDA will disclose the identity of the therapeutic agent and its potential use. Orphan drug designation does not shorten the PDUFA goal dates for the regulatory review and approval process, although it does convey certain advantages such as tax benefits and exemption from the PDUFA application fee.

If a product with orphan designation receives the first FDA approval for the disease or condition for which it has such designation or for a select indication or use within the rare disease or condition for which it was designated, the product generally will receive orphan drug exclusivity. Orphan drug exclusivity means that the FDA may not approve another sponsor’s marketing application for the same drug for the same condition for seven years, except in certain limited circumstances. Orphan exclusivity does not block the approval of a different product for the same rare disease or condition, nor does it block the approval of the same product for different conditions. If a drug designated as an orphan drug ultimately receives marketing approval for an indication broader than what was designated in its orphan drug application, it may not be entitled to exclusivity.

Orphan drug exclusivity will not bar approval of another product under certain circumstances, including if a subsequent product with the same drug for the same condition is shown to be clinically superior to the approved product on the basis of greater efficacy or safety, or providing a major contribution to patient care, or if the company with orphan drug exclusivity is not able to meet market demand. This is the case despite an earlier court opinion holding that the Orphan Drug Act unambiguously required the FDA to recognize orphan drug exclusivity regardless of a showing of clinical superiority.

In September 2021, the Court of Appeals for the 11th Circuit held that, for the purpose of determining the scope of market exclusivity, the term “same disease or condition” in the statute means the designated “rare disease or condition” and could not be interpreted by the FDA to mean the “indication or use.” Thus, the court concluded, orphan drug exclusivity applies to the entire designated disease or condition rather than the “indication or use.” It is unclear how this court decision will be implemented by the FDA.

Patent Term Restoration and Extension

A patent claiming a new drug product may be eligible for a limited patent term extension under the Hatch-Waxman Act, which permits a patent restoration of up to five years for patent term lost during product development and the FDA regulatory review. The restoration period granted on a patent covering a product is typically one-half the time between the effective date of athe IND for the clinical investigation involving human beings is begun and the submission date of an application, plus the time between the submission date of an application and the ultimate approval date. Patent term restoration cannot be used to extend the remaining term of a patent past a total of 14 years from the product’s approval date. Only one patent applicable to an approved product is eligible for the extension, and the application for the extension must be submitted prior to the expiration of the patent in question. A patent that covers multiple products for which approval is sought can only be extended in connection with one of the approvals. The United States Patent and Trademark Office reviews and approves the application for any patent term extension or restoration in consultation with the FDA.

Health Care Law and Regulation

Health care providers and third-party payors play a primary role in the recommendation and prescription of drug products that are granted marketing approval. Arrangements with providers, consultants, third-party payors and customers are subject to broadly applicable fraud and abuse, anti-kickback, false claims laws, patient privacy laws, and regulations and other health care laws and regulations that may constrain business and/or financial arrangements. Restrictions under applicable federal and state health care laws and regulations, include the following:

Further, some state laws require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government in addition to requiring manufacturers to report information related to payments to physicians and other health care providers or marketing expenditures. Additionally, some state and local laws require the registration of pharmaceutical sales representatives in the jurisdiction. 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.

Pharmaceutical Insurance Coverage and Health Care Reform

In the United States and markets in other countries, patients who are prescribed treatments for their conditions and providers performing the prescribed services generally rely on third-party payors to reimburse all or part of the associated health care costs. Significant uncertainty exists as to the coverage and reimbursement status of products approved by the FDA and other government authorities. Thus, even if a product candidate is approved, sales of the product will depend, in part, on the extent to which third-party payors, including government health programs in the United States such as Medicare and Medicaid, commercial health insurers and managed care organizations, provide coverage and establish adequate reimbursement levels for, the product. 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 are increasingly challenging the prices charged, examining the medical necessity and reviewing the cost-effectiveness of medical products and services and imposing controls to manage costs. Third-party payors may limit coverage to specific products on an approved list, also known as a formulary, which might not include all of the approved products for a particular indication.

In order to secure coverage and reimbursement for any product that might be approved for sale, a company may need to conduct expensive pharmacoeconomic studies in order to demonstrate the medical necessity and cost-effectiveness of the product, in addition to the costs required to obtain FDA or other comparable marketing approvals. Nonetheless, product candidates may not be considered medically necessary or cost effective. A decision by a third-party payor not to cover a product could reduce physician utilization once the product is approved and have a material adverse effect on sales, results of operations and financial condition. Additionally, a payor’s decision to provide coverage for a product does not imply that an adequate reimbursement rate will be approved. Further, one payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage and reimbursement for the product, and the level of coverage and reimbursement can differ significantly from payor to payor.

The containment of health care costs also has become a priority of federal, state and foreign governments and the prices of products have been a focus in this effort. Governments have shown significant interest in implementing cost-containment programs, including price controls, restrictions on 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 a company’s revenue generated from the sale of any approved products. Coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which a company or its collaborators receive marketing approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

There have been a number of federal and state proposals during the last few years regarding the pricing of pharmaceutical and biopharmaceutical products, limiting coverage and reimbursement for drugs and biologics and other medical products, government control and other changes to the health care system in the United States. In March 2010, President Obama signed into law the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Affordability Reconciliation Act, or collectively the ACA. In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted. In August 2011, the Budget Control Act of 2011, among other things, created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2013 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs. These changes included aggregate reductions to Medicare payments to providers of up to 2% per fiscal year, which went into effect in April 2013 and will remain in effect through 20302031 under the Coronavirus Aid, Relief, and Economic Security Act, or the CARES Act. These Medicare sequester reductions have been suspended through the end of March 2022. From April 2022 through June 2022 a 1% sequester cut will be in effect, with the full 2% cut resuming thereafter. The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. These laws may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices we may obtain for any of our product candidates for which we may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used.

Since enactment of the ACA, there have been, and continue to be, numerous legal challenges and Congressional actions to repeal and replace provisions of the law. For example, with enactment of the Tax Cuts and Jobs Act of 2017, or TCJA, which was signed by President Trump on December 22, 2017, Congress repealed the “individual mandate.” The repeal of this provision, which requires most Americans to carry a minimal level of health insurance, became effective in 2019.  

Further, on December 14, 2018, a U.S. District Court judge in the Northern District of Texas ruled that the individual mandate portion of the ACA is an essential and inseverable feature of the ACA, and therefore because the mandate was repealed as part of the Tax Cuts and Jobs Act,TCJA, the remaining provisions of the ACA are invalid as well. On December 18, 2019, the Court of Appeals for the Fifth Circuit affirmed the lower court’s ruling that the individual mandate portion of the ACA is unconstitutional and it remanded the case to the district court for reconsideration of the severability question and additional analysis of the provisions of the ACA. Thereafter, theThe U.S. Supreme Court agreed to hearheard this case. Oral argument in the case took place on November 10, 2020 and, a ruling byon June 17, 2021, dismissed this action after finding that the Court is expected sometime this year.plaintiffs do not have standing to challenge the constitutionality of the ACA.  Litigation and legislation over the ACA are likely to continue, with unpredictable and uncertain results.

The Trump administration also took executive actions to undermine or delay implementation of the ACA, including directing federal agencies with authorities and responsibilities under the ACA to waive, defer, grant exemptions from, or delay the implementation of any provision of the ACA that would impose a fiscal or regulatory burden on states, individuals, healthcare providers, health insurers, or manufacturers of pharmaceuticals or medical devices. On January 28, 2021, however, President Biden issued a new Executive Order which directs federal agencies to reconsider rules and other policies that limit Americans’ access to health care, and consider actions that will protect and strengthen that access.  Under this Order, federal agencies are directed to re-examine: policies that undermine protections for people with pre-existing conditions, including complications related to COVID-19; demonstrations and waivers under Medicaid and the ACA that may reduce coverage or undermine the programs, including work requirements; policies that undermine the Health Insurance Marketplace or other markets for health insurance; policies that make it more difficult to enroll in Medicaid and the ACA; and policies that reduce affordability of coverage or financial assistance, including for dependents.

The costsprices of prescription pharmaceuticals have also been the subject of considerable discussion in the United States. To date, thereThere have been several recent U.S. congressional inquiries, as well as proposed and enacted state and federal legislation designed to, among other things, bring more transparency to drugpharmaceutical pricing, review the relationship between pricing and manufacturer patient programs, and reduce the costs of drugspharmaceuticals under Medicare and reform government program reimbursement methodologies for drug products. To those ends,Medicaid.  In 2020, President Trump issued fiveseveral executive orders intended to lower the costs of prescription drug products but it is unclear whether, and to what extent,certain provisions in these orders have been incorporated into regulations.  These regulations include an interim final rule implementing a most favored nation model for prices that would tie Medicare Part B payments for certain physician-administered pharmaceuticals to the lowest price paid in other economically advanced countries, effective January 1, 2021. That rule, however, has been subject to a nationwide preliminary injunction and, on December 29, 2021, CMS issued a final rule to rescind it. With issuance of this rule, CMS stated that it will remainexplore all options to incorporate value into payments for Medicare Part B pharmaceuticals and improve beneficiaries' access to evidence-based care.

In addition, in force underOctober 2020, HHS and the Biden

Administration. Further on September 24, 2020, the Trump Administration finalizedFDA published a rulemakingfinal rule allowing states or certainand other non-federal government entities to submitdevelop a Section 804 Importation Program, or SIP, to import certain prescription drugs from Canada into the United States. The final rule is currently the subject of ongoing litigation, but at least six states (Vermont, Colorado, Florida, Maine, New Mexico, and New Hampshire) have passed laws allowing for the importation program proposals toof drugs from Canada with the FDAintent of developing SIPs for review and approval. Applicants are required to demonstrate that their importation plans pose no additional risk to public health and safety and will result in significant cost savingsapproval by the FDA.  Further, on November 20, 2020, HHS finalized a regulation removing safe harbor protection for consumers.

The FDA has issued draft guidance that would allowprice reductions from pharmaceutical manufacturers to import their own FDA-approved drugs that are authorizedplan sponsors under Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The implementation of the rule has been delayed by the Biden administration from January 1, 2022 to January 1, 2023 in response to ongoing litigation. The rule also creates a new safe harbor for sale in other countries (multi-market approved products).price reductions reflected at the point-of-sale, as well as a new safe harbor for certain fixed fee arrangements between pharmacy benefit managers and manufacturers, the implementation of which have also been delayed by the Biden administration until January 1, 2023.

At the state level, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biological 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. A number of states, for example, require drug manufacturers and other entities in the drug supply chain, including health carriers, pharmacy benefit managers, wholesale distributors, to disclose information about pricing of pharmaceuticals. In addition, regional health care authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other health care programs. These measures could reduce the ultimate demand for our products, once approved, or put pressure on our product pricing. 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, which could result in reduced demand for our product candidates or additional pricing pressures.

Review and Approval of Medicinal Products in the European Union

In order to market any product outside of the United States, a company must also comply with numerous and varying regulatory requirements of other countries and jurisdictions regarding quality, safety and efficacy and governing, among other things, clinical trials, marketing authorization, commercial sales and distribution of products. Whether or not it obtains FDA approval for a product, an applicanta sponsor will need to obtain the necessary approvals by the comparable non-U.S. regulatory authorities before it can commence clinical trials or marketing of the product in those countries or jurisdictions. Specifically, the process governing approval of medicinal products in the EU generally follows the same lines as in the United States. It entails satisfactory completion of preclinical studies and adequate and well-controlled clinical trials to establish the safety and efficacy of the product for each proposed indication. It also requires the submission to the relevant competent authorities of a marketing authorization application, or MAA, and granting of a marketing authorization by these authorities as part of a national authorization procedure, or to the EMA as part of a centralized procedure, before the product can be marketed and sold in the EU.

Clinical Trial Approval

TheOn January 31, 2022, the new Clinical Trials Regulation (EU) No 536/2014 became effective in the European Union and replaced the prior Clinical Trials Directive 2001/20/EC,EC. The new regulation aims at simplifying and streamlining the Directive 2005/28/EC on GCPauthorization, conduct and the related national implementing provisions of the individual member states of the European Union, or EU Member States, govern the system for the approvaltransparency of clinical trials in the European Union. Under this system,the new coordinated procedure for the approval of clinical trials, the sponsor of a clinical trial to be conducted in more than one Member State of the European Union, or EU Member State, will only be required to submit a single application for approval. The submission will be made through the Clinical Trials Information System, a new clinical trials portal overseen by the EMA and available to clinical trial sponsors, competent authorities of the EU Member States and the public.

The main characteristics of the regulation include: a streamlined application procedure via a single entry point, the “EU Portal and Database”; a single set of documents to be prepared and submitted for the application as well as simplified reporting procedures for clinical trial sponsors; and a harmonized procedure for the assessment of applications for clinical trials, which is divided in two parts. Part I is assessed by the appointed reporting EU Member State, whose assessment report is submitted for review by the sponsor and all other competent authorities of all EU Member States in which an applicantapplication for authorization of a clinical trial has been submitted, or Concerned Member States. Part II is assessed separately by each Concerned Member State. Strict deadlines have been established for the assessment of clinical trial applications. The role of the relevant ethics committees in the assessment procedure will continue to be governed by the national law of the Concerned Member State. However, overall related timelines will be defined by the Clinical Trials Regulation.

The new regulation did not change the preexisting requirement that a sponsor must obtain prior approval from the competent national authority of the EU Member StatesState in which the clinical trial is to be conducted. If the clinical trial is conducted in different EU Member States, the competent authorities in each of these EU Member States must provide their approval for the conduct of the clinical trial. Furthermore, the applicantsponsor may only start a clinical trial at a specific study site after the competentapplicable ethics committee has issued a favorable opinion. The clinical trial application must be accompanied by, among other documents, an investigational medicinal product dossier (the Common Technical Document) with supporting information prescribed by Directive 2001/20/EC, Directive 2005/28/EC, where relevant the implementing national provisions of the individual EU Member States and further detailed in applicable guidance documents.

In April 2014, the new Clinical Trials Regulation, (EU) No 536/2014, or Clinical Trials Regulation, was adopted. The Clinical Trials Regulation will be directly applicable in all the EU Member States, repealing the current Clinical Trials Directive 2001/20/EC and replacing any national legislation that was put in place to implement the Directive. Conduct of all clinical trials performed in the EU will continue to be bound by currently applicable provisions until the new Clinical Trials Regulation becomes applicable. The extent to which on-going clinical trials will be governed by the Clinical Trials Regulation will depend on when the Clinical Trials Regulation becomes applicable and on the duration of the individual clinical trial. If a clinical trial continues for more than three years from the day on which the Clinical Trials Regulation becomes applicable the Clinical Trials Regulation will at that time begin to apply to the clinical trial.

The Clinical Trials Regulation was published on June 16, 2014 but has not yet become effective. As of January 1, 2020, the website of the European Commission reported that the implementation of the Clinical Trials Regulation was dependent on the development of a fully functional clinical trials portal and database, which would be confirmed by an independent audit, and that the new legislation would come into effect six months after the European Commission publishes a notice of this confirmation. The website indicated that the audit was expected to commence in December 2020. In late

2020, the EMA indicated that it plans to focus on the findings of a system audit; improving the usability, quality and stability of the clinical trial information system; and knowledge transfer to prepare users and their organizations for the new clinical trial system.  The EMA has indicated that the system will go live in December 2021.

As in the United States, parties conducting certain clinical trials must post clinical trial information in the EU at the EudraCT website: https://eudract.ema.europa.eu.

PRIME Designation in the European Union

In March 2016, the European Medicines Agency, or EMA, launched an initiative to facilitate development of product candidates in indications, often rare, for which few or no therapies currently exist. The PRIority MEdicines, or PRIME, scheme is intended to encourage drug development in areas of unmet medical need and provides accelerated assessment of products representing substantial innovation reviewed under the centralized procedure. Products from small- and medium-sized enterprises may qualify for earlier entry into the PRIME scheme than larger companies. Many benefits accrue to sponsors of product candidates with PRIME designation, including but not limited to, early and proactive regulatory dialogue with the EMA, frequent discussions on clinical trial designs and other development program elements, and accelerated marketing authorization application assessment once a dossier has been submitted.

Marketing Authorization

To obtain a marketing authorization for a product under EU regulatory systems, an applicanta sponsor must submit an MAA either under a centralized procedure administered by the EMA, or one of the procedures administered by competent authorities in

the EU Member States (decentralized procedure, national procedure or mutual recognition procedure). A marketing authorization may be granted only to an applicanta sponsor established in the EU. Regulation (EC) No 1901/2006 provides that prior to obtaining a marketing authorization in the EU, applicantssponsors have to demonstrate compliance with all measures included in an EMA-approved Paediatric Investigation Plan, or PIP, covering all subsets of the pediatric population, unless the EMA has granted (1) a product-specific waiver, (2) a class waiver or (3) a deferral for one or more of the measures included in the PIP.

The centralized procedure provides for the grant of a single marketing authorization by the European Commission that is valid across the European Economic Area (i.e. the EU as well as Iceland, Liechtenstein and Norway). Pursuant to Regulation (EC) No 726/2004, the centralized procedure is compulsory for specific products, including for medicines produced by certain biotechnological processes, products designated as orphan medicinal products, advanced therapy medicinal products and products with a new active substance indicated for the treatment of certain diseases. For products with a new active substance indicated for the treatment of other diseases and products that are highly innovative or for which a centralized process is in the interest of patients, the centralized procedure may be optional. The centralized procedure may at the request of the applicantsponsor also be used in certain other cases. We anticipate that the centralized procedure will be mandatory for the product candidates we are developing.

Under the centralized procedure, the Committee for Human Medicinal Products, or CHMP, is also responsible for conducting the initial assessment of a product and for several post-authorization and maintenance activities, such as the assessment of modifications or extensions to an existing marketing authorization. Under the centralized procedure in the EU, the maximum timeframe for the evaluation of an MAA is 210 days, excluding clock stops, when additional information or written or oral explanation is to be provided by the applicantsponsor in response to questions of the CHMP. Accelerated evaluation might be granted by the CHMP in exceptional cases when a medicinal product is of major interest from the point of view of public health and in particular from the viewpoint of therapeutic innovation. If the CHMP accepts such request, the time limit of 210 days will be reduced to 150 days but it is possible that the CHMP can revert to the standard time limit for the centralized procedure if it considers that it is no longer appropriate to conduct an accelerated assessment. At the end of this period, the CHMP provides a scientific opinion on whether or not a marketing authorization should be granted in relation to a medicinal product. Within 15 calendar days of receipt of a final opinion from the CHMP, the European Commission must prepare a draft decision concerning an application for marketing authorization. This draft decision must take the opinion and any relevant provisions of EU law into account. Before arriving at a final decision on an application for centralized authorization of a medicinal product the European Commission must consult the Standing Committee on Medicinal Products for Human Use. The Standing Committee is composed of representatives of the EU Member States and chaired by a non-voting European Commission representative. The European Parliament also has a related “droit de regard”. The European Parliament’s role is to ensure that the European Commission has not exceeded its powers in deciding to grant or refuse to grant a marketing authorization.

The European Commission may grant a so-called “marketing authorization under exceptional circumstances”. Such authorization is intended for products for which the applicantsponsor can demonstrate that it is unable to provide comprehensive data on the efficacy and safety under normal conditions of use, because the indications for which the product in question is intended are encountered so rarely that the applicantsponsor cannot reasonably be expected to provide comprehensive evidence, or in the present state of scientific knowledge, comprehensive information cannot be provided, or it would be contrary to generally accepted principles of medical ethics to collect such information. Consequently, marketing authorization under exceptional circumstances may be granted subject to certain specific obligations, which may include the following:

Regulatory Data Protection in the European Union

In the EU, innovative medicinal products approved on the basis of a complete independent data package qualify for eight years of data exclusivity upon marketing authorization and an additional two years of market exclusivity pursuant to Directive 2001/83/EC. Regulation (EC) No 726/2004 repeats this entitlement for medicinal products authorized in accordance the centralized authorization procedure. Data exclusivity prevents applicantssponsors for authorization of generics of these

innovative products from referencing the innovator’s data to assess a generic (abridged) application for a period of eight years. During an additional two-year period of market exclusivity, a generic marketing authorization application can be submitted and authorized, and the innovator’s data may be referenced, but no generic medicinal product can be placed on the EU market until the expiration of the market exclusivity.

Periods of Authorization and Renewals

A marketing authorization has an initial validity for five years in principle. The marketing authorization may be renewed after five years on the basis of a re-evaluation of the risk-benefit balance by the EMA or by the competent authority of the EU Member State. The European Commission or the competent authorities of the EU Member States may decide, on justified grounds relating to pharmacovigilance, to proceed with one further five-year period of marketing authorization. Once subsequently definitively renewed, the marketing authorization shall be valid for an unlimited period. Any authorization which is not followed by the actual placing of the medicinal product on the EU market (in case of centralized procedure) or on the market of the authorizing EU Member State within three years after authorization ceases to be valid.

Pediatric Studies and Exclusivity

Prior to obtaining a marketing authorization in the EU, applicantssponsors must demonstrate compliance with all measures included in an EMA-approved PIP covering all subsets of the pediatric population, unless the EMA has granted a product-specific waiver, a class waiver, or a deferral for one or more of the measures included in the PIP. The respective requirements for all marketing authorization procedures are laid down in Regulation (EC) No 1901/2006, the so-called Paediatric Regulation. This requirement also applies when a company wants to add a new indication, pharmaceutical form or route of administration for a medicine that is already authorized. The Paediatric Committee of the EMA, or PDCO, may grant deferrals for some medicines, allowing a company to delay development of the medicine for children until there is enough information to demonstrate its effectiveness and safety in adults. The PDCO may also grant waivers when development of a medicine for children is not needed or is not appropriate, such as for diseases that only affect the elderly population. Before an MAA can be filed, or an existing marketing authorization can be amended, the EMA determines that companies actually comply with the agreed studies and measures listed in each relevant PIP. If an applicanta sponsor obtains a marketing authorization in all EU Member States, or a marketing authorization granted in the centralized procedure by the European Commission, and the study results for the pediatric population are included in the product information, even when negative, the medicine is then eligible for an additional six-month period of qualifying patent protection through extension of the term of the Supplementary Protection Certificate, or SPC.

Orphan Drug Designation and Exclusivity

Regulation (EC) No. 141/2000, as implemented by Regulation (EC) No. 847/2000 provides that a drug can be designated as an orphan drug by the European Commission if its sponsor can establish: that the product is intended for the diagnosis, prevention or treatment of (1) a life-threatening or chronically debilitating condition affecting not more than five in ten thousand persons in the EU when the application is made, or (2) a life-threatening, seriously debilitating or serious and chronic condition in the EU and that without incentives it is unlikely that the marketing of the drug in the EU would generate sufficient return to justify the necessary investment. For either of these conditions, the applicantsponsor must demonstrate that there exists no satisfactory method of diagnosis, prevention or treatment of the condition in question that has been authorized in the EU or, if such method exists, the drug will be of significant benefit to those affected by that condition.

Once authorized, orphan medicinal products are entitled to ten years of market exclusivity in all EU Member States and in addition a range of other benefits during the development and regulatory review process including scientific assistance for study protocols, authorization through the centralized marketing authorization procedure covering all member countries and a reduction or elimination of registration and marketing authorization fees. However, 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. Marketing authorization may also be granted to a similar medicinal product with the same orphan indication if this product is safer, more effective or otherwise clinically superior to the original orphan medicinal product. The period of market exclusivity may, in addition, be reduced to six years if it can be demonstrated on the basis of available evidence that the original orphan medicinal product is sufficiently profitable not to justify maintenance of market exclusivity.

Regulatory Requirements After a Marketing Authorization has been Obtained

In case an authorization for a medicinal product in the EU is obtained, the holder of the marketing authorization is required to comply with a range of requirements applicable to the manufacturing, marketing, promotion and sale of medicinal products. These include:

Pricing Decisions for Approved Products

In the EU, pricing and reimbursement schemes vary widely from country to country. Some countries provide that products may be marketed only after a reimbursement price has been agreed. Some countries may require the completion of additional studies that compare the cost-effectiveness of a particular product candidate to currently available therapies or so-called health technology assessments, in order to obtain reimbursement or pricing approval. For example, the EU provides options for its Member States to restrict the range of products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. Member States may approve a specific price for a product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the product on the market. Other Member States allow companies to fix their own prices for products, but monitor and control prescription volumes and issue guidance to physicians to limit prescriptions. Recently, many countries in the EU have increased the amount of discounts required on pharmaceuticals and these efforts could continue as countries attempt to manage health care expenditures, especially in light of the severe fiscal and debt crises experienced by many countries in the EU. The downward pressure on health care costs in general, particularly prescription products, has become intense. As a result, increasingly high barriers are being erected to the entry of new products. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing used by various Member States, and parallel trade, i.e., arbitrage between low-priced and high-priced Member States, can further reduce prices. There can be no assurance that any country that has price controls or

reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any products, if approved in those countries

Brexit and the Regulatory Framework in the United Kingdom

On June 23, 2016, the electorate in theThe United Kingdom voted in favor of leavingKingdom’s withdrawal from the EU commonly referred to as Brexit. Following protracted negotiations, the United Kingdom left the EUtook place on January 31, 2020. Under the withdrawal agreement, there is a transitional period until December 31, 2020 (extendable by up to two years).  On December 24, 2020,The EU and the United Kingdom andreached an agreement on their new partnership in the EU entered into a Trade and Cooperation Agreement.Agreement, or the Agreement, which was applied provisionally beginning on January 1, 2021 and which entered into force on May 1, 2021. The agreement sets out certain procedures for approvalAgreement focuses primarily on free trade by ensuring no tariffs or quotas on trade in goods, including healthcare products such as medicinal products. Thereafter, the EU and recognition of medical products in each jurisdiction. Since the regulatory framework for pharmaceutical products in the United Kingdom covering quality, safetywill form two separate markets governed by two distinct regulatory and efficacy of pharmaceutical products, clinical trials, marketing authorization, commercial sales and distribution of pharmaceutical products is derived from EU directives and regulations, Brexit could materially impactlegal regimes. As such, the future regulatory regimeAgreement seeks to minimize barriers to trade in goods while accepting that applies to products and the approval of product candidates inborder checks will become inevitable as a consequence that the United Kingdom.Kingdom is no longer part of the single market. As of January 1, 2021, the Medicines and Healthcare products Regulatory Agency, or the MHRA, became responsible for supervising medicines and medical devices in Great Britain, comprising England, Scotland and Wales under domestic law whereas Northern Ireland continues to be subject to EU rules under the Northern Ireland Protocol. The MHRA will rely on the Human Medicines Regulations 2012 (SI 2012/1916) (as amended), or the HMR, as the basis for regulating medicines. The HMR has incorporated into the domestic law of the United Kingdom the body of EU law governing medicinal products that pre-existed prior to the United Kingdom’s withdrawal from the EU.

General Data Protection Regulation

The collection, use, disclosure, transfer, or other processing of personal data regarding individuals in the European Union, including personal health data, is subject to the GDPR, which became effective on May 25, 2018. The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal data, including requirements

relating to processing health and other sensitive data, obtaining consent of the individuals to whom the personal data relates, providing information to individuals regarding data processing activities, implementing safeguards to protect the security and confidentiality of personal data, providing notification of data breaches, and taking certain measures when engaging third-party processors. The GDPR also imposes strict rules on the transfer of personal data to countries outside the European Union, including the United States, and permits data protection authorities to impose large penalties for violations of the GDPR, including potential fines of up to €20 million or 4% of annual global revenues, whichever is greater. The GDPR also confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. Compliance with the GDPR will be a rigorous and time-intensive process that may increase the cost of doing business or require companies to change their business practices to ensure full compliance.

Employees and Human Capital Resources

As of December 31, 2020,2021, we had 2741 full-time employees, including a total of 35 employees with M.D., Pharm.D. or Ph.D. degrees. Of these full-time employees, 1829 employees are engaged in research and development. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and additional employees. The principal purposes of our equity incentive plans are to attract, retain and motivate selected employees, consultants and directors through the granting of stock-based compensation awards.

Corporate Information

We were incorporated under the laws of the State of Delaware on January 26, 2016. Our principal executive offices are located at 116 Huntington Avenue, 6th Floor, Boston, Massachusetts 02116, and our telephone number is (617) 206-2020. Our website address is www.imaratx.com. Our website and the information contained on, or that can be accessed through, our website will not be deemed to be incorporated by reference in, and are not considered part of, this Annual Report on Form 10-K.

Item 1A. RiskRisk Factors.

Investing in our common stock involves a high degree of risk. You should carefully consider the risks and uncertainties described below together with all of the other information contained in this Annual Report on Form 10-K, including our consolidated financial statements and the related notes appearing elsewhere in this Annual Report on Form 10-K and in our other filings with the Securities and Exchange Commission, before deciding to invest in our common stock. Such risks and uncertainties may be amplified by the COVID-19 pandemic and its potential impact on our business and the global economy. The risks described below are not the only risks facing our company. The occurrence of any of the following risks, or of additional risks and uncertainties not presently known to us, could cause our business, prospects, operating results and financial condition to suffer materially. In such event, the trading price of our common stock could decline, and you might lose all or part of your investment.

Risks Related to Our Financial Position and Need for Additional Capital

We have incurred significant losses since our inception, and we expect to incur losses over the next several years.

Since inception, we have incurred significant operating losses. Our net loss was $23.5$51.4 million for the year ended December 31, 20192021 and was $41.4 million for the year ended December 31, 2020. As of December 31, 2020,2021, we had an accumulated deficit of $96.1$147.5 million. As noted below, we have identified conditions and events that raise substantial doubt about our ability to continue as a going concern.  To date, we have financed our operations primarily through the sale of common stock in our initial public offering, or IPO, and the sale of convertible preferred stock. We have devoted substantially all of our financial resources and efforts to research and development, including clinical trials and preclinical studies of IMR-687. We are still in the early stages of development of our only product candidate, IMR-687.tovinontrine (IMR-687). We expect to continue to incur significant expenses and operating losses over the next several years.years as we continue to develop tovinontrine and any other product candidates we may develop. Our operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially as we:

We have identified conditions and events that raise substantial doubt about our ability to continue as a going concern.

As of December 31, 2021, we had cash, cash equivalents and investments of $90.3 million. We expect these available cash resources will be able to fund our operating expenses and capital expenditure requirements substantially through the first quarter of 2023. We have based this assessment on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. Based on our available cash resources, there is substantial doubt about our ability to continue as a going concern within one year after the date of filing this Annual Report on Form 10-K. If we are unable to obtain additional funding, we will be forced to delay, reduce in scope or eliminate some of our research and development efforts for IMR-687 and potentially pursue clinical activities for IMR-687 in heart failure with preserved ejection fraction, or HFpEF;

We have never generated revenue from product sales and may never achieve or maintain profitability.

To become and remain profitable, we must succeed in developing, and eventually commercializing, a product or products that generate significant revenue. The ability to achieve this success will require us to be effective in a range of challenging activities, including completing preclinical testing and clinical trials of IMR-687tovinontrine and any other product candidates we may identify and pursue,develop, obtaining regulatory approval for these product candidates and manufacturing, marketing and selling any products for which we may obtain regulatory approval. We are only in the preliminary stages of mostmany of these activities. We may never succeed in these activities and, even if we do, may never generate revenues that are significant enough to achieve profitability. Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able 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 depress the value of our company and could impair our ability to raise capital, expand our business, maintain our research and development efforts, diversify our pipeline of product candidates or even continue our operations. A decline in the value of our company could also cause our stockholders to lose all or part of their investment.

We are heavily dependent on the success of IMR-687, our only product candidate.tovinontrine.

We currently have no products that are approved for commercial sale and may never be able to develop marketable products. We expect that a substantial portion of our efforts and expenditures over the next several years will be devoted to IMR-687,tovinontrine, which is currently our only product candidate.candidate in clinical development. Accordingly, our business currently depends heavily on the successful development, regulatory approval and commercialization of IMR-687.tovinontrine. We cannot be certain that IMR-687tovinontrine will receive regulatory approval or be successfully commercialized even if we receive regulatory approval. If we were required to discontinue development of IMR-687tovinontrine or if IMR-687tovinontrine does not receive regulatory approval or fails to achieve significant market acceptance, we likely would be delayed by many years in our ability to achieve profitability, if ever, and may not be able to generate sufficient revenue to continue our business.

We will need substantial additional funding. If we are unable to raise capital when needed, we could be forced to delay, reduce or eliminate our product development programs or commercialization efforts.

We expect to devote substantial financial resources to our ongoing and planned activities, including our OLEArdent Phase 2b and Phase 2bOLE clinical trials of IMR-687tovinontrine in patients with SCD, and our Forte Phase 2b clinical trial in patients with β-thalassemia.β-thalassemia and our planned Phase 2 clinical trial of tovinontrine in HFpEF. We expect our expenses to increase substantially in connection with our ongoing and planned activities, particularly as we advance our preclinical activities and clinical trials of and seek regulatory approval for IMR-687tovinontrine and other product candidates we may identify.develop. In addition, if we obtain regulatory approval for IMR-687tovinontrine and any other product candidates we may identify and pursue,develop, we expect to incur significant commercialization expenses related to product manufacturing, sales, marketing and distribution. Furthermore, we expect to incur additional costs associated with operating as a public company.

Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain regulatory approval and achieve product sales. In addition, any product candidates, if approved, may not achieve commercial success. Commercial revenues, if any, will not be derived unless and until we can achieve sales of products, which we do not anticipate for manyseveral years, if at all. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations.

In April 2021, we entered into a sales agreement, or the Sales Agreement, with Cantor Fitzgerald & Co, LLC, as sales agent, providing for the offering, issuance and sale by us of up to an aggregate $75.0 million of our common stock from time to time in “at-the-market” offerings under a shelf registration statement on Form S-3.  As of December 31, 2020,2021, we have issued and sold 231,291 shares of common stock under the Sales Agreement, resulting in net proceeds of $1.4 million after deducting commissions and offering expenses. The extent to which we utilize the Sales Agreement as a source of funding will depend on a number of factors, including the prevailing market price of our common stock, general market conditions, the extent to which we are able to secure funds from other sources, and restrictions on our ability to sell common stock pursuant to the Sales Agreement to the extent we are then subject to restrictions on our ability to utilize the Form S-3 shelf registration statement to sell more than one-third of the market value of our public float, meaning the aggregate market value of voting and non-voting common stock held by non-affiliates, in any trailing 12-month period. Accordingly, we may not be able to sell shares under the Sales Agreement at prices or amounts that we deem acceptable, and there can be no assurance that we will sell any further common stock pursuant to the Sales Agreement.

As of December 31, 2021, we had cash, cash equivalents and investments of $88.2$90.3 million. We believe that our existing cash, cash equivalents and investments as of December 31, 2021 will enable us to fund our operating expenses and capital expenditure requirements into mid-2022.substantially through the first quarter of 2023. However, we have based this estimate on assumptions that may prove to be wrong, and our operating plan may change as a result of many factors currently unknown to us. As a result, we could deplete our capital resources sooner than we currently expect.

Our future capital requirements will depend on many factors, including:

We will continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all. For example, the global COVID-19 pandemic created significant uncertainty in the global financial markets, which may reduce our ability to raise additional capital. In addition, we may seek additional capital when market conditions are favorable, or for strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. If adequate funds are not available to us on a timely basis or on terms acceptable to us, we may be required to delay, limit, reduce or terminate preclinical studies, clinical trials or other development activities for one or more product candidates or discovery stage programs or delay, limit, reduce or terminate our establishment of sales and marketing capabilities or other activities that may be necessary to commercialize any product candidates.

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to our technologies or product candidates.

Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. We do not have any committed external source of funds. Based on our available cash resources, there is substantial doubt about our ability to continue as a going concern within one year after the date of filing this Annual Report on Form 10-K, and we expect that we will need to raise additional capital in the near term.  To the extent that we raise additional capital through the sale of equity or convertible debt securities, our stockholders’ ownership interests will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights as common stockholders. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, selling or licensing our assets, making capital expenditures or declaring dividends.

If we raise additional funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt financings when needed or on terms acceptable to us, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

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

We commenced activities in 2016 and are a clinical-stage company. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, developing our technology, and undertaking preclinical

studies and early-stage clinical trials of our sole product candidate, IMR-687.tovinontrine and acquiring and commencing preclinical studies for IMR-261. We have not yet demonstrated our ability to successfully develop any product candidate, obtain regulatory approvals, manufacture a commercial scale product or arrange for a third-party to do so on our behalf, or conduct sales and marketing activities necessary for successful product commercialization. Consequently, 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 products.

In addition, as our business grows, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors. We will need to transition at some point from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in such a transition.

We expect our financial condition and operating results to fluctuate significantly from quarter-to-quarter and year-to-year due to a variety of factors, many of which are beyond our control. Accordingly, our stockholders should not rely upon the results of any quarterly or annual periods as indications of future operating performance.

Our ability to use our net operating losses, or NOLs, and research and development tax credit carryforwards to offset future taxable income may be subject to certain limitations.

We have a history of cumulative losses and anticipate that we will continue to incur significant losses in the foreseeable future; thus, we do not know whether or when we will generate taxable income necessary to utilize our NOLs or research and development tax credit carryforwards. As of December 31, 2020,2021, we had federal NOLs of $91.7$139.2 million and state NOLs of $85.5$129.4 million.

In general, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, a corporation that undergoes an “ownership change,” generally defined as a greater than 50 percentage point change (by value) in its equity ownership by certain stockholders over a three year period, is subject to limitations on its ability to utilize its pre-change NOLs and research and development tax credit carryforwards to offset future taxable income. We have not conducted a study to assess whether any such ownership changes have occurred. We may have experienced such ownership changes in the past, including as a result of our public offering of shares of common stock in July 2021, and may experience such ownership changes in the future as a result of subsequent changes in our stock ownership (which may be outside our control). As a result, if, and to the extent that, we earn net taxable income, our ability to use our pre-change NOLs and research and development tax credit carryforwards to offset such taxable income may be subject to limitations.

There is also a risk that due to regulatory changes, such as suspensions on the use of NOLs, or other unforeseen reasons, our existing NOLs could expire or otherwise become unavailable to offset future income tax liabilities. As described below in “Changes in tax laws or in their implementation or interpretation may adversely affect our business and financial condition,” the Tax Cuts and Jobs Act, or the TCJA, as amended by the Coronavirus Aid, Relief, and Economic Security Act, or CARES Act, includes changes to U.S. federal tax rates and the rules governing NOL carryforwards that may significantly impact our ability to utilize our NOLs to offset taxable income in the future. Additionally, state NOLs generated in one state cannot be used to offset income generated in another state. For these reasons, even if we attain profitability, we may be unable to use a material portion of our NOLs and other tax attributes.

Our business and operations have beenandmay continue to be adversely affected by the ongoing COVID-19 pandemic, as may the operations of our suppliers and manufacturers and other third-party service providers.

In December 2019, a novel strain of coronavirus, calledThe COVID-19 emerged in Wuhan, Hubei Province, China, which has now spread globally, including to the United States, the United Kingdom and the European Union. The pandemic and government measures taken in response to it have had a significant impact, both direct and indirect, on businesses and commerce, as worker shortages have occurred; supply chains have been disrupted; facilities and production have been suspended; and demand for certain goods and services, such as medical services and supplies, has spiked, while demand for other goods and services, such as travel, has fallen. The future progression of the pandemic and its effects on our business and operations areremain uncertain.

The spread of COVID-19 pandemic has affected our operations to date, including by causing delays in the conduct of our clinical trials. While we have not experienced any significant disruptions with the third parties on which we rely, the COVID-19 pandemic, or the spread of COVID-19, or another infectious disease, could also negatively affect the operations of our third-party manufacturers, which could result in disruptions in the supply of IMR-687.tovinontrine or any other product candidates we may develop. In addition, mostmany of our employees are currently working remotely, and we are temporarily restricting travel and attendance at industry events by our employees.remotely. The COVID-19 pandemic continues to rapidly evolve and could more significantly impact our operations in the future.

We have enrolled and seek to enroll patients in our ongoing clinical trials at sites located both in the United States and internationally. The COVID-19 pandemic has delayed and may continue to delay or otherwise adversely affect these clinical development activities, including our ability to recruit and retain patients in our ongoing clinical trials, as a result of many factors, including:

For example, the COVID-19 pandemic has resulted in disruptions to our clinical trial operations, including some missed and incomplete patient visits in our recently completed Phase 2a clinical trial of IMR-687tovinontrine in SCD, anddelays to some patient visits in our OLE clinical trial in SCD, as well as site activation and enrollment delays and delays in review of our regulatory submissions with respect to our Ardent and Forte Phase 2b clinical trials of IMR-687tovinontrine in SCD and β-thalassemia. More recently, we have also experienced some disruptions with the supply chain of third-party vendors who assist us in the conduct of our clinical trials.  In addition, the COVID-19 pandemic may affect the operations of the U.S. Food and Drug Administration, or FDA, and other health authorities, which could result in delays of regulatory actions related to our programs, including with respect to IMR-687.tovinontrine. Any negative impact that the COVID-19 pandemic has on recruiting or retaining patients in our clinical trials, the ability of our suppliers to provide materials for our product candidates, or the regulatory review process could cause additional delays which could materially and adversely affect our ability to obtain regulatory approval for and to commercialize our product candidates, increase our operating expenses, affect our ability to raise additional capital and have a material adverse effect on our financial results. In addition, if any of our clinical trial patients contract COVID-19, they may have adverse health outcomes that could impact the results of our clinical trials.

Additionally, while the potential economic impact and the duration of the COVID-19 pandemic is difficult to assess or predict, theany impact of the COVID-19 pandemic on the global financial markets may reduce our ability to access capital, which could negatively impact our short-term and long-term liquidity.

While we expect the impacts of COVID-19 will continue to have some adverse effect on our business, the extent to which COVID-19 impacts our clinical trials, research and development activities and operations will depend on future developments, which are highlyremain uncertain and cannot be predicted with confidence, including the duration of the pandemic, new information which may emerge concerning the severity of COVID-19 and variants of COVID-19, the actions to contain COVID-19 or treat its impact and changes in government spending or priorities, among others. The COVID-19 pandemic is a widespread health crisis that continues to adversely affect the global economy and financial markets of many countries, resulting in anand any economic downturn that could also affect our operations, our ability to conduct our clinical trials, our ability to raise additional funds through public offerings and the volatility of our stock price and trading in our stock. Even after the COVID-19 pandemic has subsided, we may continue to experience adverse impacts to our business as a result of any economic recession or depression that has occurred or may occur in the future.

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

We are early in our development efforts and heavily dependent on the success of our sole product candidate, IMR-687.tovinontrine. If we are unable to successfully complete clinical development, obtain regulatory approval for, or commercialize IMR-687,tovinontrine, or experience delays in doing so, our business will be materially harmed.

To date, we have invested a majority of our efforts and financial resources in the preclinical and clinical development of IMR-687.tovinontrine. Our future success is heavily dependent on our ability to successfully develop, obtain regulatory approval for and commercialize IMR-687. IMR-687tovinontrine. Tovinontrine is currently our only product candidate in clinical development and we are currently testing it as part of our OLE clinical trial in SCDArdent and ourForte Phase 2b clinical trials in SCD and β-thalassemia. It may beβ-thalassemia, our OLE clinical trial in SCD and we plan to initiate a significant time before IMR-687 can advance into a pivotalPhase 2 clinical trial if at all.of tovinontrine in HFpEF. We cannot be certain that IMR-687tovinontrine will be successful in clinical trials or receive regulatory approval.

The success of IMR-687tovinontrine will depend on several factors, including the following:

Many of these factors are beyond our control, including clinical outcomes, the regulatory review process, potential threats to our intellectual property rights and the manufacturing, marketing and sales efforts of any future collaborator. If we are unable to develop, receive marketing approval for and successfully commercialize IMR-687,tovinontrine, or if we experience delays as a result of any of these factors or otherwise, we may need to spend significant additional time and resources to identify otheradditional product candidates, advance them through preclinical and clinical development and apply for regulatory approvals, which would adversely affect our business, prospects, financial condition and results of operations.

Clinical drug development involves a lengthy and expensive process, with an uncertain outcome. We may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of any product candidates.

The risk of failure for IMR-687tovinontrine and any other product candidates we may develop is high. It is impossible to predict when or if IMR-687tovinontrine and any other product candidates we may develop will prove effective or safe in humans or will receive regulatory approval. Before obtaining marketing approval from regulatory authorities for the sale of any product candidate, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy of such product candidate in humans. We have not yet begun or completed a pivotal clinical trial of IMR-687, which is currently our onlytovinontrine or any other product candidate. Clinical trials may fail to demonstrate that IMR-687tovinontrine and any other product candidates we may develop are safe for humans and effective for indicated uses. Even if the clinical trials are successful, changes in marketing approval policies during the development period, changes in or the enactment or promulgation of additional statutes, regulations or guidance or changes in regulatory review for each submitted product application may cause delays in the approval or rejection of an application.

Before we can commence clinical trials for a product candidate, we must complete extensive preclinical testing and studies that support our planned investigational new drug applications, or INDs, and other regulatory filings in the United States and abroad. We cannot be certain of the timely completion or outcome of our preclinical testing and studies, and cannot predict if the FDA or other regulatory agencies will accept our proposed clinical programs or if the outcome of our preclinical testing and studies will ultimately support the further development of any product candidates. As a result, we cannot be sure that we will be able to submit INDs or similar applications for our preclinical programs on the timelines we expect, if at all, and we cannot be sure that submission of INDs or similar applications will result in the FDA or other regulatory authorities allowing clinical trials to begin. Furthermore, product candidates are subject to continued preclinical safety studies, which may be conducted concurrent with our clinical testing. The outcomes of these safety studies may delay the launch of or enrollment in future clinical trials and could impact our ability to continue to conduct our clinical trials.

Clinical trials are expensive, difficult to design and implement, can take many years to complete and are uncertain as to outcome. We cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, or at all. A failure of one or more clinical trials can occur at any stage of testing, which may result from a multitude of factors, including,

but not limited to, flaws in study design, dose selection issues, placebo effects, patient enrollment criteria and failure to demonstrate favorable safety or efficacy traits.

We may experience numerous unforeseen events during, or as a result of, clinical trials that could delay or prevent our ability to receive marketing approval or commercialize IMR-687tovinontrine and any other product candidates we may develop, including:

We face additional important risks related to the enrollment and completion of our clinical trials of IMR-687tovinontrine as a result of the COVID-19 pandemic, which are further described in “—Our business and operations have been and may continue to be adversely affected by the ongoing COVID-19 pandemic, as may the operations of our suppliers and manufacturers and other third-party service providers.”

If we are required to conduct additional clinical trials or other testing of IMR-687tovinontrine beyond those that we currently contemplate, if we are unable to successfully complete clinical trials or other testing of IMR-687tovinontrine or any other product candidates we may develop, if the results of these trials or tests are not positive or are only modestly positive or if there are safety concerns, we may:

Our product development costs will also increase if we experience delays in testing or in obtaining marketing approvals. We do not know whether any of our preclinical studies or clinical trials will begin as planned, will need to be restructured or will be completed on schedule, or at all. We may also change the design or protocol of one or more of our clinical trials, including to add additional patients or arms, which could result in increased costs and expenses and/or delays. Significant preclinical study or clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize any product candidates or allow our competitors to bring products to market before we do and impair our ability to successfully commercialize any product candidates and may harm our business and results of operations.

Because we are developing IMR-687 using new endpoints and methodologies,plan to use a surrogate endpoint for our development of tovinontrine in HFpEF, the FDA or other regulatory authorities may not consider the endpoints of our clinical trialssuch endpoint to predict or provide clinically meaningful results.

There are currently limited therapies approvedIn the second quarter of 2022, we plan to treat SCD. To date,initiate a Phase 2 clinical trial of tovinontrine in HFpEF, in which we have concentrated a significant portion of our product research and development efforts on developing a novel therapeutic forplan to evaluate changes in N-terminal pro b-type natriuretic peptide, or NT-proBNP, levels as the treatment of SCD, and our future success depends on the success of this therapeutic approach.primary endpoint. The clinical trial requirements of the FDA and other comparable regulatory agencies and the criteria these regulators use to determine the safety and efficacy of any product candidate vary substantially according to the type, complexity, novelty and intended use and market of the potential product.  To date there are only four FDA-approved drugstwo approved products for SCD: voxelotor (marketedHFpEF, and as Oxbryta), crizanlizumab (marketed as Adakveo), hydroxyurea and L-glutamine (marketed as Endari), and there are no approved therapies that target phosphodiesterase 9, or PDE9. As a result, the design and conduct of clinical trials for a therapeutic product candidate such as IMR-687 that targets PDE9 in SCD patientsHFpEF is subject to uncertainties and unknown risks, and we may experience setbacks with our ongoing or planned clinical trials of IMR-687 in SCD because of the limited clinical experience with its mechanism of action in these patients.

In particular, regulatory authorities in the United States and the European Union have not issued definitive guidance as to how to measure and achieve efficacy in treatments for SCD. As a result, the design and conduct of clinical trials of IMR-687 may take longer, be more costly or be less effective as part of the novelty of development in SCD. We may use new or novel endpoints or methodologies, such as both red and white blood cell biomarkers in our IMR-687 clinical trials, and the FDA or other regulatory authorities may not consider the endpoints of our clinical trials to provide clinically meaningful results.risks.  Even if applicable regulatory authorities do not object to our proposed endpointsuse of a biomarker endpoint in an earlier stage clinical trial, such regulatory authorities may require evaluation of additional or different clinical endpoints in later-stage clinical trials. Additionally, if we pursue accelerated approval or other expedited regulatory approval mechanisms for IMR-687, the FDA or another regulatory authority may determine that the biomarker efficacy endpoint we select for evaluation is not sufficiently predictive of clinical benefit to support accelerated approval. For example, while the FDA commented at our face-to-face Type B meeting that our revised Phase 2b trial design and approach to data collection to support HbF asAs a potential surrogate endpoint was acceptable, the FDA stressed the importance of defining clear and strong assumptions and having robust results, which would be evaluated by the FDA to test if an increase of at least 3% in HbF would provide meaningful clinical benefit and therefore constitute an acceptable surrogate endpoint for a future pivotal trial of IMR-687 in SCD. Ifresult, we are not able to demonstrate clinical benefit related to this endpoint to the FDA’s satisfaction,expect we will havemay need to consider other endpoints for thea pivotal program which may include greater levels of HbF increases.in HFpEF that has the ability to show clear clinical benefit.

Even if the FDA does find our clinical trial success criteria to be sufficiently validated and clinically meaningful, we may not achieve the pre-specified endpoint to a degree of statistical significance deemed approvable in any pivotal or other clinical trials we may conduct for IMR-687.tovinontrine. Further, even if we do achieve the pre-specified criteria, our trials may produce results that are unpredictable or inconsistent with the results of the more traditional efficacy endpoints in the trial. The FDA also could give overriding weight to other efficacy endpoints over a primary endpoint, even if we achieve statistically significant results on that primary endpoint, if we do not do so on our secondary or other efficacy endpoints. The FDA also weighs the benefits of a product against its risks and the FDA may view the efficacy results in the context of safety as not being supportive of approval. Other regulatory authorities in the European Union and other countries may make similar findings with respect to these endpoints.

The outcome of preclinical studies and earlier-stage clinical trials may not be predictive of the success of later-stage clinical trials.

The outcome of preclinical testing and earlier-stage clinical trials may not be predictive of the success of later-stage clinical trials. IMR-687Tovinontrine and any other product candidates we may develop may fail to show the desired safety and

efficacy in clinical development despite positive results in preclinical studies or having successfully advanced through initial clinical trials. For example, in our SCD clinical trials, IMR-687tovinontrine may not be effective at increasing red blood cell biomarkers that include HbF, F-cells, hemoglobin, and reducing reticulocytes, indirect bilirubin, and LDH. Furthermore,VOCs in the same manner as we have experienced in our Phase 2a clinical trials, IMR-687 may not impact adhesion/white blood cell markers such as P-selectin, E-selectin,trial of tovinontrine or VCAM. Even if IMR-687 successfully increases or decreases, as applicable, these biomarkers inour OLE clinical trials, such increase or decrease may not result in overall clinical benefit. A lacktrial of clinical benefit may be due to insufficient dosing or for other reasons.tovinontrine. Additionally, any other positive results generated in our Phase 2a, OLE or Ardent Phase 2b clinical trialstrial of IMR-687tovinontrine in adults with SCD would not ensure that we will achieve similar results in larger, pivotal clinical trials or in clinical trials of IMR-687tovinontrine in adolescent and pediatric populations with SCD. We face similar risks in our development of tovinontrine in areas outside of SCD, including ß-thalassemia and HFpEF, as well as in development of other product candidates we may develop, including IMR-261. Several companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials even after achieving promising results in preclinical testing and earlier-stage clinical trials, and we cannot be certain that we will not face similar setbacks. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products. Furthermore, the failure of any product candidate to demonstrate safety and efficacy in any clinical trial could negatively impact the perception of any other product candidates then under development and/or cause the FDA or other regulatory authorities to require additional testing before approving any other such product candidates.

Interim top-line and preliminary results from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures, which could result in material changes in the final data.

From time to time, we may publish interim top-line or preliminary results from our clinical trials. Interim results from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Preliminary or top-line results also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, interim and preliminary data should be viewed with caution until the final data are available. Differences between preliminary or interim data and final data could significantly harm our business prospects and may cause the trading price of our common stock to fluctuate significantly.

As an organization, we have never conducted pivotal clinical trials, and we may be unable to do so for IMR-687tovinontrine or any other product candidates we may develop.

We will need to successfully complete pivotal clinical trials in order to obtain the approval of the FDA, the European Medicines Agency, or EMA, or other regulatory agencies to market IMR-687tovinontrine or any futureother product candidate. Carrying out later-stage clinical trials is a complicated process. As an organization, we have not previously conducted any later stage or pivotal clinical trials. In order to do so, we will need to expand our clinical development and regulatory capabilities, and we may be unable to recruit qualified personnel. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to approval of IMR-687tovinontrine or futureother product candidates. We may require more time and incur greater costs than our competitors and may not succeed in obtaining regulatory approvals of product candidates that we develop. Failure to commence or complete, or delays in, our planned clinical trials, could prevent us from or delay us in commercializing our product candidates.

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.

Identifying and qualifying patients to participate in clinical trials for IMR-687tovinontrine and any other product candidates we may develop is critical to our success. Successful and timely completion of clinical trials will require that we enroll a sufficient number of patients who remain in the trial until its conclusion. We may not be able to initiate or continue clinical trials for IMR-687tovinontrine and any other product candidates we may develop if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside of the United States. For example, the prevalence of patients with SCD and β-thalassemia in the United States and Europe is estimated to be low. Accordingly, there are limited patient pools from which to draw for clinical trials of IMR-687.tovinontrine for the treatment of SCD and β-thalassemia. We may not be able to identify, recruit, and enroll a sufficient number of patients to complete our clinical trials of IMR-687tovinontrine because of the perceived

risks and benefits of IMR-687,tovinontrine, the availability of competing therapies and clinical trials, the proximity and availability of clinical trial sites for prospective subjects and the subject referral practices of physicians, among other factors.

Patient enrollment is affected by a variety of other factors, including:

In addition, the COVID-19 pandemic has impacted, and is likely to continue to directly or indirectly impact the pace of enrollment in our clinical trials for at least the next several months and possibly longer as patients may avoid, may not be allowed to, or may not be able to travel to healthcare facilities and physicians’ offices unless due to a health emergency.

Our inability to locate and enroll a sufficient number of patients for our clinical trials would result in significant delays, could require us to abandon one or more clinical trials altogether and could delay or prevent our receipt of necessary regulatory approvals. Enrollment delays in our clinical trials may result in increased development costs for IMR-687tovinontrine and any other product candidates we may develop, which would cause the value of our company to decline and limit our ability to obtain additional financing.

Changes in methods of product candidate manufacturing or formulation may result in additional costs or delay.

As product candidates proceed through preclinical studies to late-stage clinical trials towards potential approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods and formulation, are altered along the way in an effort to optimize processes and results. As an example, we expect to utilize an oral solution formulation of IMR-687 for clinical development in pediatric populations with SCD that will differ from the oral tablet formulation of IMR-687 we have used in our clinical trials to date. Such changes carry the risk that they will not achieve these intended objectives. Any of these changes could cause IMR-687tovinontrine or any other product candidates we may develop to perform differently and affect the results of planned clinical trials or other future clinical trials conducted with the materials manufactured using altered processes. Such changes may also require additional testing, FDA notification or FDA approval. This could delay completion of clinical trials, require the conduct of bridging clinical trials or the repetition of one or more clinical trials, increase clinical trial costs, delay approval of IMR-687the affected product candidate and jeopardize our ability to commence sales and generate revenue.

If serious adverse events or unacceptable side effects are identified during the development of IMR-687tovinontrine and any other product candidates we may develop, we may need to abandon or limit our development of those product candidates.

Clinical trials by their nature utilize a sample of the potential patient population. We have only begun to evaluate IMR-687evaluated tovinontrine in a limited number of subjects and our ongoing clinical trials of tovinontrine are being conducted at a limited durationhigher doses than previous clinical trials of exposure.tovinontrine. Accordingly, any rare and severe side effects of IMR-687tovinontrine may be uncovered only in later stages of our current and future clinical development. Many product candidates that initially showed promise in early stage testing have later been found to cause side effects that prevented their further development. If IMR-687tovinontrine and any other product candidates we may develop are associated with undesirable side effects in clinical trials or have characteristics that are unexpected in clinical trials or preclinical testing, we may need to abandon their

development or limit development to more narrow uses or subpopulations in which the side effects or other characteristics are less prevalent, less severe or more

acceptable from a risk-benefit perspective. In pharmaceutical development, many compounds that initially show promise in early-stage or clinical testing are later found to cause side effects that delay or prevent further development of the compound.

Additionally, if results of our clinical trials reveal unacceptable side effects, we, the FDA or similar regulatory authorities outside of the United States, or the IRBs or Ethics Committees at the institutions in which our studies are conducted could suspend or terminate our clinical trials or the FDA or similar foreign regulatory authorities could order us to cease clinical trials or deny approval of IMR-687tovinontrine and any other product candidates we may develop for any or all targeted indications. Treatment-related side effects could also affect patient recruitment or the ability of enrolled patients to complete any of our clinical trials. In addition, while not considered adverse events, in our Phase 1 clinical trial of IMR-687 in healthy volunteers, individual subjects were noted to have sporadic heart rates of greater than 100 bpm, including placebo subjects. One subject at 4.5 mg/kg per day had multiple readings greater than 100 bpm, including at study start, prior to any administration of study drug. If we elect or are forced to suspend or terminate any clinical trial of IMR-687tovinontrine and any other product candidates we may develop, the commercial prospects of such product candidate will be harmed, and our ability to generate product revenue from such product candidate will be delayed or eliminated. Any of these occurrences could materially harm our business.

We are also developing IMR-687tovinontrine in combination with other therapies, which exposes us to additional risks.

We are developing IMR-687tovinontrine both as a monotherapy and in combination with hydroxyurea, a currently approved therapy for SCD, and may develop future product candidates in combination with one or more currently approved therapies. Even if any product candidate we develop were to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risks that the FDA or similar regulatory authorities outside of the United States could revoke approval of the therapy used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues could arise with these existing therapies. This could result in our own products being removed from the market or being less successful commercially.

If any product candidate receives marketing approval and we, or others, later discover that the drug is less effective than previously believed or causes undesirable side effects that were not previously identified, our ability to market the drug could be compromised.

We conduct, and intend to conduct in the future, clinical trials of product candidates in carefully defined subsets of patients who have agreed to enter into clinical trials. Consequently, it is possible that our clinical trials may indicate an apparent positive effect of a product candidate that is greater than the actual positive effect, if any, or alternatively fail to identify undesirable side effects. If any product candidate receives regulatory approval, and we, or others, later discover that it is less effective than previously believed, or causes undesirable side effects, a number of potentially significant negative consequences could result, including:

Any of these events could prevent us from achieving or maintaining market acceptance of a particular product candidate, if approved, and could significantly harm our business, financial condition, and results of operations.

We may not be successful in our efforts to identify or discover additional product candidates and may fail to capitalize on programs or product candidates that may present a greater commercial opportunity or for which there is a greater likelihood of success.

If we do not successfully develop and eventually commercialize products, we will not obtain product revenue in future periods, resulting in significant harm to our financial position and adversely affecting our share price. We recently completed a Phase 2a clinical trial of IMR-687 in patients with SCD and are currently conducting an OLE clinical trial andour Ardent Phase 2b clinical trial of IMR-687tovinontrine in patients with SCD, our Forte Phase 2b clinical trial of tovinontrine in patients with β-thalassemia and our OLE clinical trial of tovinontrine in patients with SCD.  In addition, a key elementwe expect to commence clinical development of our business plan is to expandtovinontrine in HFpEF in the breadthsecond quarter of indications for IMR-687 for the treatment of β-thalassemia and HFpEF. We are currently conducting a Phase 2b clinical trial of IMR-687 in patients with β-thalassemia and recently completed pre-clinical research in HFpEF.2022. A failure to establish IMR-687tovinontrine as a viable treatment for SCD, β-thalassemia and/or HFpEF could harm our business prospects. In addition, we may explore IMR-687tovinontrine in other indications or acquire additional product candidates for development. However, thereFor example, in 2020 we acquired IMR-261, however we have not yet commenced clinical development of this product candidate and any future development efforts for IMR-261 may not be successful.  There can be no assurance that we will be successful in our efforts to identify or acquire otheradditional potential product candidates. Even if we identify or acquire otheradditional product candidates, there can be no assurance that our development efforts will be successful.

Additionally, because we have limited resources, we may forego or delay pursuit of opportunities with certain programs or product candidates or for indications that later prove to have greater commercial potential. For example, we currently intend to focus our capital resources primarily on the development of IMR-687.tovinontrine. However, the development of IMR-687tovinontrine may ultimately prove to be unsuccessful or less successful than another potential product candidate in our pipeline that we might have chosen to pursue on a more aggressive basis with our capital resources. If we do not accurately evaluate the commercial potential for a particular product candidate, we may relinquish valuable rights to that product candidate through strategic collaboration, licensing or other arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate. Alternatively, we may allocate internal resources to a product candidate in a therapeutic area in which it would have been more advantageous to enter into a partnering arrangement.

We are conducting clinical trials of IMR-687tovinontrine at clinical trial sites outside the United States, and the FDA may not accept data from trials conducted in such international locations.

In addition to our clinical sites in the United States, we are currently conducting clinical trials of IMR-687tovinontrine at clinical sites outside of the United States. For example, our Ardent and Forte Phase 2b clinical trials of IMR-687tovinontrine in SCD and β-thalassemia are currently being conducted or expected to be conducted at clinical sites in Europe, Asia and Africa. Although the FDA may accept data from clinical trials conducted outside the United States, acceptance of these data is subject to conditions imposed by the FDA. For example, the clinical trial must be well designed and conducted and be performed by qualified investigators in accordance with ethical and Good Clinical Practice, or GCP, principles. The trial population must also adequately represent the U.S. population, and the data must be applicable to the U.S. population and U.S. medical practice in ways that the FDA deems clinically meaningful. In addition, while these clinical trials are subject to the applicable local laws, FDA acceptance of the data will depend on its determination that the trials also complied with all applicable U.S. laws and regulations. If the FDA does not accept the data from any trial conducted or from particular clinical trial sites located outside the United States, it would likely result in the need for additional trials, which would be costly and time-consuming and could delay or permanently halt our development of the applicable product candidates.

Even if any product candidate receives marketing approval, it may fail to achieve the degree of market acceptance by physicians, patients, third-party payors and others in the medical community necessary for commercial success.

If any product candidate receives marketing approval, it may nonetheless fail to gain sufficient market acceptance by physicians, patients, third-party payors and others in the medical community. Sales of medical products depend in part on the willingness of physicians to prescribe the treatment, which is likely to be based on a determination by these physicians that the products are safe, therapeutically effective and cost effective. In addition, the inclusion or exclusion of products from treatment guidelines established by various physician groups and the viewpoints of influential physicians can affect the willingness of other physicians to prescribe the treatment. We cannot predict whether physicians, physicians’ organizations, hospitals, other healthcare providers, government agencies or private insurers will determine that our product is safe, therapeutically effective and cost effective as compared with competing treatments. Efforts to educate the medical

community and third-party payors on the benefits of IMR-687tovinontrine and any other product candidates we may develop may require significant resources and may not be successful. If IMR-687tovinontrine and any other product candidates we may develop do not achieve an adequate level of acceptance, we may not generate significant product revenues and we may not become

profitable. The degree of market acceptance of IMR-687tovinontrine and any other product candidates we may develop, if approved for commercial sale, will depend on a number of factors, including:

If we are unable to establish sales, marketing and distribution capabilities or enter into sales, marketing and distribution agreements with third parties, we may not be successful in commercializing any product candidates if and when they are approved.

We do not have a sales or marketing infrastructure and have no experience in the sale, marketing or distribution of pharmaceutical products. To achieve commercial success for any product for which we have obtained marketing approval, we will need to establish a sales, marketing and distribution organization, either ourselves or through collaborations or other arrangements with third parties.

In the future, we expect that we would begin to build a sales and marketing infrastructure to market IMR-687tovinontrine and any other product candidates we may develop, in the United States and potentially in Europe, if and when approved by the applicable regulatory authority. There are risks involved with establishing our own sales, marketing and distribution capabilities. For example, recruiting and training a sales force is expensive and time-consuming and could delay any product launch. If the commercial launch of a product candidate for which we recruit a sales force and establish marketing capabilities is delayed or does not occur for any reason, we would have prematurely or unnecessarily incurred these commercialization expenses. These efforts may be costly, and our investment would be lost if we cannot retain or reposition our sales and marketing personnel.

Factors that may inhibit our efforts to commercialize our products on our own include:

If we are unable to establish our own sales, marketing and distribution capabilities and we enter into arrangements with third parties to perform these services, our product revenues and our profitability, if any, are likely to be lower than if we

were to market, sell and distribute any products that we develop ourselves. In addition, we may not be successful in entering into arrangements with third parties to sell, market and distribute any product candidates or may be unable to do so on terms that are acceptable to us. We likely will have little control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market our products effectively. If we do not establish sales, marketing and distribution capabilities successfully, either on our own or in collaboration with third parties, we will not be successful in commercializing any product candidates.

We face substantial competition, which may result in others discovering, developing or commercializing products before or more successfully than we do.

The development and commercialization of new drug products is highly competitive. We face competition with respect to IMR-687,tovinontrine and will face competition with respect to any product candidates that we may seek to develop or commercialize in the future, from major pharmaceutical companies, specialty pharmaceutical companies and biotechnology companies worldwide. There are a number of large pharmaceutical and biotechnology companies that currently market and sell products or are pursuing the development of products for the treatment of the same disease indications we are pursuing. Some of these competitive products and therapies are based on scientific approaches that are the same as or similar to our approach, and others are based on entirely different approaches. Potential competitors also include academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection and establish collaborative arrangements for research, development, manufacturing and commercialization.

In the area of SCD, we expect to face competition from voxelotor (marketed as Oxbryta by Global Blood Therapeutics, Inc., or GBT), crizanlizumab (marketed as Adakveo by Novartis AG, or Novartis), HU (marketed under trade names including DROXIADroxia by Bristol-Myers Squibb Company and SIKLOS by Addmedica, as well as in generic form) and L-glutamine (marketed as Endari), which are currently the only FDA-approved therapies for the treatment of SCD. In addition, with respect to SCD, we are aware of several product candidates in clinical development, which could be competitive with product candidates that we may successfully develop and commercialize. For example, there are a number of companies in clinical development for gene editing/therapy treatments, including bluebird bio, Inc., Aruvant Sciences, Inc., CRISPR Therapeutics AG (in collaboration with Vertex Pharmaceuticals Incorporated), Sangamo Therapeutics, Inc. (in collaboration with Sanofi), Intellia Therapeutics, Inc. (in collaboration with Novartis), Graphite Bio, Inc. and Editas Medicine, Inc. There are also several companies advancing therapeutic approaches outside of gene editing/therapy, including GBT, Agios Pharmaceuticals, Inc., Forma Therapeutics, Inc., Vifor Pharma Ltd, Novo Nordisk A/S (in collaboration with EpiDestiny, Inc.), Fulcrum Therapeutics, Inc., CSL Ltd. and Pfizer, Inc.

In the area of ß-thalassemia, we expect to face competition from ZYNTEGLOZynteglo (marketed by bluebird bio, Inc.), which is currently only approved in Europe for the treatment of ß-thalassemiaß -thalassemia and for which FDA approval is currently being sought, as well as REBLOZYLReblozyl (marketed by Bristol-Myers Squibb Co. and Acceleron Pharma Inc.), which is approved in the United States for the treatment of anemia in adult patients with ß-thalassemia who require regular RBC transfusions. In addition, with respect to SCD,ß-thalassemia, we are aware of several product candidates in clinical development, including several product candidates for which FDA approval is currently being sought, which could be competitive with product candidates that we may successfully develop and commercialize.  Novo Nordisk A/S (in collaboration with EpiDestiny, Inc.), Aruvant Sciences, Inc., Sangamo Therapeutics Inc., or Sangamo (in collaboration with Sanofi), Fulcrum Therapeutics, Inc., Agios Pharmaceuticals, Inc., Forma Therapeutics, Inc., Intellia Therapeutics, Inc. (in collaboration with Novartis), Editas Medicine, Inc., For example, there are a number of companies in clinical development for gene editing/therapy treatments, including bluebird bio, Inc, CRISPR Therapeutics AG or CRISPR (in collaboration with Vertex Pharmaceuticals Incorporated, or Vertex)Incorporated) and SyrosIonis Pharmaceuticals. There are also several companies advancing therapeutic approaches outside of gene editing/therapy, including Agios Pharmaceuticals, Inc, Forma Therapeutics, Inc., Silence Therapeutics, Inc. and Vifor Pharma Ltd.

In the area of HFpEF, we expect to face competition from Entresto (marketed by Novartis) which is currently the only FDA-approved therapy for HFpEF.  We are also aware of several drugs approved for other indications that are likely to seek near-term marketing approval for HFpEF including Jardiance (Eli Lilly & Co.), Farxiga (Astra Zeneca, PLC), Invokana (Johnson & Johnson) and Zynquista (Lexicon Pharmaceuticals, Inc).  In addition, Bristol-Myers Squibb Co., Cytokinetics, Inc., Acceleron Pharma, Inc., Palatin Technologies, Inc., Cardurion Pharmaceuticals, Inc. (in collaboration with GBT)and TransThera Biosciences Co., Ltd., among potentially other companies, are also developing therapeutic approaches for patients with SCD. Novo Nordisk A/S (in collaboration with EpiDestiny, Inc.), Sangamo (in collaboration with Sanofi), CRISPR (in collaboration with Vertex), Agios Pharmaceuticals, Inc. and Syros Pharmaceuticals, Inc. (in collaboration with GBT), among potentially other companies, are developing therapeutic approaches for patients with transfusion-dependent or non-transfusion-dependent b-thalassemia. See “Business—Competition” for additional information regarding competing products and product candidates.HFpEF.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. In addition, our ability to compete may be affected in many cases by insurers or other third-party payors seeking to encourage the use of generic products. If any product candidates achieve marketing approval, we expect that they would be priced at a significant premium over competitive generic products.

Many of the companies against which we are competing or against which we may compete in the future 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.

Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller and other early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These third parties compete with us in recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.

If the market opportunities for IMR-687tovinontrine and any other product candidates we may develop are smaller than we believe they are, our revenue may be adversely affected and our business may suffer. Moreover, because the target patient populations we are seeking to treat in SCD and β-thalassemia are relatively small, and the addressable patient population even smaller, we must be able to successfully identify patients and capture a significant market share to achieve profitability and growth.

We focusTo date, we have primarily focused our research and product development on treatments for rare inherited genetic disorders of hemoglobin. The prevalence of SCD is approximately 100,000 individuals in the United States and 134,000 individuals in the European Union. Similarly, the prevalence of β-thalassemia globally is estimated to be 288,000 individuals and the aggregate prevalence of β-thalassemia in the European Union and United States is estimated to be 19,000 individuals. Given the small number of patients who have the diseases that we are targeting,SCD and β-thalassemia, it is critical to our ability to grow and become profitable that we continue to successfully identify patients with these rare diseases. Our projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with IMR-687tovinontrine and any other product candidates we may develop, are based on our beliefs and estimates. These estimates have been derived from a variety of sources, including the scientific literature, surveys of clinics, patient foundations or market research that we conducted, and may prove to be incorrect or contain errors. New studies may change the estimated incidence or prevalence of these diseases. The number of patients may turn out to be lower than expected. The effort to identify patients with diseases we seek to treat is in early stages, and we cannot accurately predict the number of patients for whom treatment might be possible. Additionally, the potentially addressable patient population for IMR-687tovinontrine and any other product candidates we may develop may be limited or may not be amenable to treatment with IMR-687tovinontrine and any other product candidates we may develop, and new patients may become increasingly difficult to identify or gain access to, which would adversely affect our results of operations and our business. Further, even if we obtain significant market share for IMR-687tovinontrine and any other product candidates we may develop for SCD and β-thalassemia, because the potential target populations are very small, we may never achieve profitability despite obtaining such significant market share.

OurThe target patient populations for SCD and β-thalassemia are relatively small, and there are currently limited standard of care treatments directed at SCD.SCD and β-thalassemia. As a result, the pricing and reimbursement of IMR-687tovinontrine and any other product candidates we may develop, if approved, is uncertain, but must be adequate to support commercial infrastructure. If we are unable to obtain adequate levels of reimbursement, our ability to successfully market and sell IMR-687tovinontrine and any other product candidates we may develop will be adversely affected.

We rely on CMOs to manufacture IMR-687tovinontrine and expect to rely on CMOs to manufacture any other product candidates we may develop. If we are unable to enter into such arrangements as expected or if such organizations do not meet our supply requirements, development and/or commercialization of IMR-687tovinontrine and any other product candidates we may develop may be delayed.

We do not have any manufacturing facilities. We currently rely on a single manufacturer of active pharmaceutical ingredient, or API, for IMR-687tovinontrine and a different single manufacturer for finished drug product, and we expect to continue to rely on third parties to manufacture clinical supplies of IMR-687tovinontrine and any other product candidates we may develop and commercial supplies of our products, if and when approved for marketing by applicable regulatory authorities, as well as for packaging, sterilization, storage, distribution and other production logistics. If we are unable to enter into such arrangements on the terms or timeline we expect, development and/or commercialization of IMR-687tovinontrine and any other product candidates we may develop may be delayed. Reliance on third-party manufacturers may expose us to different risks than if we were to manufacture product candidates ourselves. If these third parties do not successfully carry out their contractual duties, meet expected deadlines or manufacture any product candidates in accordance with regulatory requirements, if there are disagreements between us and such parties or if such parties are unable to expand capacities to support commercialization of any product candidates for which we obtain marketing approval, we may not be able to fulfill, or may be delayed in

producing sufficient product candidates to meet, our supply requirements. These facilities may also be affected by natural disasters, such as floods or fire, or geopolitical developments, or such facilities could face manufacturing issues, such as contamination or regulatory concerns following a regulatory inspection of such facility. In such instances, we may need to locate an appropriate replacement third-party facility and establish a contractual relationship, which may not be readily

available or on acceptable terms, which would cause additional delay and increased expense, and may have a material adverse effect on our business.

Our third-party manufacturers are subject to regulatory inspection from time to time, including inspection and approval by the FDA and similar foreign regulators before we can commence the manufacture and sale of any product candidates, and thereafter. Failure by our third-party manufacturers to pass such inspections and otherwise satisfactorily complete the approval regimen with respect to IMR-687tovinontrine and any other product candidates we may develop may result in regulatory actions such as the issuance of FDA Form 483 notices of observations, warning letters or injunctions or the loss of operating licenses.

We or our third-party manufacturers may also encounter shortages in the raw materials or API necessary to produce IMR-687tovinontrine and any other product candidates we may develop in the quantities needed for our clinical trials or, if IMR-687tovinontrine and any other product candidates we may develop are approved, in sufficient quantities for commercialization or to meet an increase in demand, as a result of capacity constraints or delays or disruptions in the market for the raw materials or API, including shortages caused by the purchase of such raw materials or API by our competitors or others. Even if raw materials or API are available, we may be unable to obtain sufficient quantities at an acceptable cost or quality. The failure of us or our third-party manufacturers to obtain the raw materials or API necessary to manufacture sufficient quantities of IMR-687tovinontrine and any other product candidates we may develop could delay, prevent or impair our development efforts and may have a material adverse effect on our business.

We face additional important risks related to our reliance on CMOs to meet our current and future supply needs of IMR-687tovinontrine as a result of the COVID-19 pandemic, which are further described in “—Our business and operations have been and may continue to be adversely affected by the ongoing COVID-19 pandemic, as may the operations of our suppliers and manufacturers and other third-party service providers.”

Even if we are able to commercialize any product candidates, the products may become subject to unfavorable pricing regulations, third-party coverage or reimbursement practices or healthcare reform initiatives, which could harm our business.

The regulations that govern marketing approvals, pricing, coverage and reimbursement for new drug products vary widely from country to country. Current and future legislation may significantly change the approval requirements in ways that could involve additional costs and cause delays in obtaining approvals. 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. As a result, we might obtain marketing approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, and negatively impact the revenues we are able to generate from the sale of the product in that country. Adverse pricing limitations may hinder our ability to recoup our investment in one or more product candidates, even if any product candidates obtain marketing approval.

Our ability to commercialize any product candidates successfully will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers and other organizations. Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. A primary trend in the U.S. healthcare industry and elsewhere is cost containment. Government authorities and other third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. Coverage and reimbursement may not be available for any product that we commercialize and, even if these are available, the level of reimbursement may not be satisfactory. Reimbursement may affect the demand for, or the price of, any product candidate for which we obtain marketing approval. Obtaining and maintaining adequate reimbursement for our products may be difficult. There can be no assurance that any product candidates, even if they are approved for sale in the United States or in other countries, will be considered medically reasonable and necessary for a specific indication or cost-effective by third-party payors. We may be required to conduct expensive pharmacoeconomic studies to justify coverage and reimbursement or the

level of reimbursement relative to other therapies. If coverage and adequate reimbursement are not available, we may not be able to successfully commercialize any product candidate for which we obtain marketing approval.

There may be significant delays in obtaining coverage and reimbursement for newly approved drugs, and coverage may be more limited than the purposes for which the drug is approved by the FDA or similar regulatory authorities outside of

the United States. Moreover, eligibility for coverage and reimbursement does not imply that a drug will be paid for in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution expenses. Interim reimbursement levels for new drugs, if applicable, may also not be sufficient to cover our costs and may not be made permanent. Reimbursement rates may vary according to the use of the drug and the clinical setting in which it is used, may be based on reimbursement levels already set for lower cost drugs and may be incorporated into existing payments for other services. 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. Further, no uniform policy for coverage and reimbursement exists in the United States. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement policies, but also have their own methods and process apart from Medicare determinations. As a result, obtaining and maintaining coverage and adequate reimbursement is often time-consuming and costly. Our inability to promptly obtain coverage and adequate reimbursement rates from both government-funded and private payors for any approved products that we develop could have a material adverse effect on our operating results, our ability to raise capital needed to commercialize products and our overall financial condition.

Our future growth depends, in part, on our ability to penetrate foreign markets, where we would be subject to additional regulatory burdens and other risks and uncertainties that, if they materialize, could harm our business.

Our future profitability will depend, in part, on our ability to commercialize IMR-687tovinontrine and any other product candidates we may develop in markets outside of the United States and the European Union. If we commercialize IMR-687tovinontrine and any other product candidates we may develop in foreign markets, we will be subject to additional risks and uncertainties, including: