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 registrant’s common stock, $0.0001 par value per share (“Common Stock”), held by non-affiliates of the registrant, based on the closing sale price of the registrant’s Common Stock on June 28, 2019,30, 2020, was $9,357,037.$12,583,469. Shares of Common Stock held by each officer and director and by each person who is known to own 10% or more of the outstanding Common Stock have been excluded in that such persons may be deemed to be affiliates of the registrant. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

As of March 20, 2020,18, 2021, the registrant had 2,867,85113,531,941 shares of Common Stock par value $0.0001, outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

None.Portions of the Definitive Proxy Statement to be filed for Phio Pharmaceuticals Corp.’s 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K.

TABLE OF CONTENTS

PHIO PHARMACEUTICALS CORP.

ANNUAL REPORT ON FORM 10-K

For the Fiscal Year Ended December 31, 20192020

FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as “intends,” “believes,” “anticipates,” “indicates,” “plans,” “expects,” “suggests,” “may,” “would,” “should,” “potential,” “designed to,” “will,” “ongoing,” “estimate,” “forecast,” “predict,” “could,” and similar references, although not all forward-looking statements contain these words. Forward-looking statements are neither historical facts nor assurances of future performance. These statements are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, projections, anticipated events and trends, the economy and other future conditions. Because forward-looking statements relate to the future, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict and many of which are outside of our control. Risks that could cause actual results to vary from expected results expressed in our forward-looking statements include, but are not limited to:

Our actual results and financial condition may differ materially from those indicated in the forward-looking statements as a result of the foregoing factors, including those identified in this Annual Report on Form 10-K under the heading Risk“Risk Factors,” for the reasons described elsewhere in this Annual Report on Form 10-K and in other filings Phio Pharmaceuticals Corp. periodically makes with the Securities and Exchange Commission. Therefore, you should not rely unduly on any of these forward-looking statements. Forward-looking statements contained in this Annual Report on Form 10-K speak as of the date hereof and Phio Pharmaceuticals Corp. does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this report.

PART I

Unless otherwise noted, (1) the term “Phio” refers to Phio Pharmaceuticals Corp. and our subsidiary, MirImmune, LLC and (2) the terms “Company,” “we,” “us” and “our” refer to the ongoing business operations of Phio and MirImmune, LLC, whether conducted through Phio or MirImmune, LLC.

Overview

Phio Pharmaceuticals Corp. (“Phio,” “we,” “our” or the “Company”) is a biotechnology company developing the next generation of immuno-oncology therapeutics based on ourits self-delivering RNAi (“INTASYL™”) therapeutic platform. The Company's efforts are focused on silencing tumor-induced suppression of the immune system through ourits proprietary INTASYL™ INTASYL platform with utility in immune cells and/orand the tumor micro-environment. OurThe Company’s goal is to develop powerful INTASYL™INTASYL therapeutic compounds that can weaponize immune effector cells to overcome tumor immune escape, thereby potentially providing patients a powerful new treatment option that goes beyond current treatment modalities.

Our development efforts areDevelopment Pipeline

We have developed a product platform based on our broadly patented INTASYL™INTASYL technology platform. Our INTASYL™ compounds do not require a delivery vehicle to penetrate into tissuesthat allows easy, precise, rapid, and selective non-genetically modified programming of adoptive cell therapy (“ACT”) cells (ex vivo, during manufacturing) and are designed to “silence” or down-regulate,of the expressiontumor micro-environment (the “TME”) (in vivo, by local application), resulting in reduced immune inhibition and in improved immunotherapy. The table below sets forth the Company’s stage of a specific gene which is over-expressed in cancer. development for its programs and product candidates:

We believe that our INTASYL™INTASYL platform uniquely positions the Company in the field of immuno-oncology because of this andfor the following reasons:

Our Development Pipeline

The table below sets forth the Company’s stage of development for its programs and product candidates:

The self-delivering nature of our compounds makes INTASYL™ INTASYL ideally suited for use with adoptive cell transfer (“ACT”) treatments andas well as for direct therapeutic use. ACT consists of the infusion of immune cells with antitumor properties.properties, after growing them in a lab to large numbers. These cells can be derived from unmodified (i.e. naturally occurring) immune cells, immune cells isolated from resected tumors, or genetically engineered immune cells recognizingthat recognize tumor neoantigen/neoepitope cells.

Currently, ACT therapies for Regardless of the treatmentsource of immune cells (ACT or naturally occurring immune cells), in patients with solid tumors, facethese cells have several hurdles.shortcomings that inhibit their full therapeutic potential. By using INTASYL technology during the manufacturing of such ACT cell products we can improve the phenotype and function of these cells, potentially leading to better therapeutic outcomes. Multiple inhibitory mechanisms restrain immune cells used in ACT from effectively eradicating tumors, including immune checkpoints, reduced cell fitness and cell persistence. Furthermore, the immunosuppressive tumor micro-environment (the “TME”) can pose a formidable barrier to immune cell infiltration and function. By using INTASYL based drugs administered directly, we can reprogram cells in the TME to help overcome these immunosuppressive mechanisms.

Phio has developed a product platform based on our INTASYL™ technology that allows easy, precise, rapid, and selective non-genetically modified programming of ACT cells (ex vivo, during manufacturing) and of the TME (in vivo, by local application), resulting in improved immunotherapy.

INTASYL Use To Improve Adoptive Cell TransferTherapy Products

ACT includesis a numberform of different typesimmune therapy based on the use of immunotherapy treatments. These treatments use immune cells, thatisolated from patients, donors or retrieved from allogeneic immune cell banks. They are grown in a lab to large numbers, followed by administering them to the bodypatient to fight the cancer cells.cancer. Sometimes, immune cells that naturally recognize a tumor are used, while other times immune cells are modified or “engineered”“genetically engineered” to make them recognize and kill the cancer cells. There are several types of ACT, including: a.) non-engineered cell therapy in which immune cells are grown from the patient’s tumor or blood, such as tumor infiltrating lymphocytes (“TILs”), or from donor blood or tissue such as natural killer (“NK”) cells, dendritic cells (“DC”) and macrophages, and b.) genetically engineered immune cells that are genetically modified to recognize specific tumor proteins and to remain in an activated state (such as T cell receptor technology (“TCRs”), chimeric antigen receptor (“CAR”) T cells, or CAR-NK cells).

In ACT,Multiple inhibitory mechanisms restrain immune cells are isolatedused in ACT from patients, donors or retrieved from allogeneiceffectively eradicating tumors, including immune checkpoints, reduced cell fitness and cell persistence, and other barriers to immune cell banks. The immune cells are then expandedinfiltration and modified before being returned and used to treat the patient.function mainly in solid tumors. We believe our INTASYL™INTASYL compounds are ideally suited to be used in combination with ACT products. With INTASYL compounds, we can unlock the full potential of ACT, by improving the immune cell function, differentiation and metabolism, in order to make these immune cells more effective.effective without the need for additional complicated manufacturing steps and/or genetic engineering.

Our approach to immunotherapy builds on well-established methodologies of ACT and involves the treatment of immune cells with ourINTASYL™ INTASYL compoundsex vivo while they are grown in the lab and before administering them to the patient. Because ourINTASYL™ INTASYL compounds do not require a delivery vehicle to penetrate into the cells, we are able to enhance the function of these cells (for example, by inhibiting the expression of immune checkpoint genes) by merely adding ourINTASYL™ INTASYL compounds during the expansion process and without the need for genetic engineering. After enhancing these cellsex vivo, they are returnedengineering, without the need for complex delivery vehicles or formulations, and without additional needed complex manufacturing steps. By adding INTASYL to the patient for treatment.

Our method introduces an important step incell culture media used during theex vivo processing of immune cells. This step uses our INTASYL™ technology to cell expansion, we can reduce or eliminate the expression of genes that make the immune cells less effective. For example, with our INTASYL™INTASYL compounds, we can reduce the expression of immunosuppressive receptors or proteins by the therapeutic immune cells, potentially enabling them to overcome tumor resistance mechanisms and thus improving their ability to destroy the tumor cells.In various types of immune cells tested to date, INTASYL™INTASYL treatment results in potent silencing while maintainingwith close to 100% transfection efficiency and while maintaining nearly full cell viability. After expanding these cells and enhancing them with INTASYL ex vivo, they are returned to the patient for treatment.

One

Considering the significant growth of the main issues with ACT is that the cells are very susceptible to the cancer signals that turn down the immune response and continuous activation of these cells causes them to become exhausted. These factors, among others, may reduce their efficacy and lifespan. Acell-based immunotherapy, a technology that can reprogram the immune cells used in ACT, such as with INTASYL™INTASYL technology, is of key interest now in the current immuno-oncology world.interest. In comparison to other technologies available, reprogramming cells with INTASYL™INTASYL does not require genetic engineering, its use is not limited to specific cell types and it can be easily integrated with cell manufacturing approaches.

Our lead product candidate and most advanced program being developed in ACT is PH-762, an INTASYL compound that targets the checkpoint protein PD-1. Checkpoint proteins, such as PD-1, normally act as a type of “off switch” that prevent T cells from attacking certain cells, such as cancer cells, in the body. Our T cells are immune cells that protect the body from cancer cells and infections.

Data developed by Phio and with collaborators has shown that PH-762 silences PD-1 checkpoint expression, thereby removing the “off switch” and resulting in enhanced T cell activation and tumor cytotoxicity. Experimental data shows that PH-762 can silence the expression of PD-1 in target human T cells in a potent and durable manner, and can increase the function of patient derived TILs for use in ACT, showing that PH-762 is applicable for use in both ACT and as a standalone direct therapeutic.

In March 2021, the Company announced that it entered into a clinical development collaboration with AgonOx, Inc. (“AgonOx”), a private company developing a pipeline of novel immunotherapy drugs targeting key regulators of the immune response to cancer. Under the agreement, the companies will collaborate on the development of novel T cell-based therapies using PH-762 and AgonOx’s “double positive” (DP) TIL technology. AgonOx has demonstrated that their DP CD8+ T cells isolated from human solid tumors (DP TILs) have increased tumor killing activity when compared to TILs that were not enriched prior to expansion. Preclinical data from AgonOx in collaboration with Phio has shown that treating DP TIL with PH-762 increases the tumor killing activity of the DP TILs even further (a two-fold increase). As a result, the use of PH-762 treated DP TILs is expected to enhance therapeutic responses in cancer data. Based on these data showing that the combination of our technologies can result in TIL therapeutics, our collaboration will focus on conducting a clinical study for PH-762 treated DP TILs. Under the terms of the collaboration agreement, AgonOx will receive financial support for the clinical trial from Phio and Phio will be entitled to certain future development milestones and sales-related royalty payments from AgonOx’s DP TIL technology. The clinical trial in ACT with PH-762 and AgonOx’s DP TIL technology is expected to start in the third quarter of 2021.

Our second product candidate in ACT is PH-894, an INTASYL compound that targets BRD4 which is a regulator of gene expression impacting cell differentiation. In previous studies, PH-894 has been shown to improve T cell function and persistence by differentiating T cells into a more active state (stem-cell like memory phenotype). Data, completed in partnership with the Karolinska Institutet in Sweden, demonstrated that the application of PH-894, was shown to silence BRD4 in human T cells during expansion for ACT, which has the potential to confer superior anti-tumor activity, for example by improving T cell persistence. With this data, we expanded our collaboration with the Karolinska Institutet to build upon these findings and develop INTASYL compounds for additional targets and cell types toward clinical application in areas of the Karolinska Institutet’s ongoing clinical research.

We currently have two product candidates that are being developedalso developing our INTASYL compound PH-804 for use in ACT, PH-762 and PH-804. PH-762, our most advanced program and lead pipeline compound, targets the checkpoint protein PD-1, a checkpoint protein on immune cells. PD-1 normally acts as a type of “off switch” that helps keep the T cells from attacking other cells in the body. T cells are immune cells that protect the body from cancer cells and are important for the activation of immune cells to fight infection. Our second pipeline compound,ACT. PH-804 targets the suppressive immune receptor TIGIT, which is a checkpoint protein present on T cells and NK cells.

Data developed in-house and with our collaborators, which include both leading academic centers and corporate institutions, has shown that PH-762 can elicit PD-1 checkpoint blockade by silencing PD-1 receptor expression resulting in enhanced T cell activation and tumor cytotoxicity. We have also shown with studies completed with our collaborators that PH-804 can silence the expression of TIGIT in NK cells and T cells, overcoming their exhaustion and thereby becoming “weaponized.”

Recent data shown by the Company as well as with our collaborators, Iovance Biotherapeutics, Inc.“off switch” and the Karolinska Institutet, at the 2019 Society for Immunotherapy of Cancer annual meeting further supports the application of INTASYL™ technology in immunotherapy of cancer. PH-762 has showncells becoming “weaponized” to silence the expression of checkpoint molecule PD-1 in target human T cells in a potent and durable manner suitable for both ACT and intra-tumoral injection, and increases function of patient derived TILs for ACT. The application of INTASYL™ compounds to novel immuno-oncology targets was shown by the silencing of BRD4, a regulator of gene expression impacting cell differentiation and function, by a BRD4 targeting INTASYL™ compound in human T cells during expansion for ACT, which has the potential to confer superior anti-tumor activity.

We expect that PH-762 can be ready to enter into the clinic with a partner in ACT therapy in the second half of 2020 and we are developing PH-804 with the aim to enter the clinic with a partner in ACT in 2021.kill cancer cells.

Direct Therapeutic Use of INTASYL Towards the Tumor Micro-Environment

The TME is the environment that surrounds and feeds a tumor, including normal cells, blood vessels, immune cells, and the extracellular matrix. A tumor can change the microenvironment and the microenvironment can affect how a tumor grows and spreads and can createThe TME is an immunosuppressive microenvironmentenvironment that inhibits the immune system’s natural ability to recognize and destroy tumor cells. This attractscells by negatively impacting how immunosuppressive cells inducesare being attracted and activates immune checkpoint expression and excludes and exhausts T cells.activated. Reprogramming different components of the TME may overcome its resistance to immunotherapy.

Such reprogramming of the TME by INTASYL™INTASYL compounds through direct local administration into the tumor, could potentially become an important form of (neo)adjuvant therapy. We believe that this will also show that our contributions with our INTASYL™ compounds in immuno-oncology are not limited to use with a cell therapy platform. Additionally, theThe Company has previously shown in a clinical setting that its INTASYL™ our INTASYL compounds are safe and well-tolerated following local administration.administration, therefore we believe that our INTASYL technology can not only be used with ACT, but can also be used as an independent therapeutic platform.

Our INTASYL™We are developing our PH-762, PH-894 and PH-804 INTASYL compounds being developedalso for use in ACT, are also being developed for use directly towardsas direct therapeutics to reprogram the TME including PH-762through in situ transfection and PH-804. We are also working on other relevant compounds for TME targets, such as PH-790, an INTASYL™ compound targeting PD-L1. PD-L1 is a protein that keepsactivation of immune cells from attacking nonharmful cells in the body. If cancer cells have large amounts of PD-L1, this “tricks” the immune system into not recognizing and attacking the tumor. Our approach with PH-790 is to block the PD-L1 protein, which may prevent cancer cells from inactivating T cells and attack the cancer.TME.

Our collaborative research agreement with Gustave Roussy, a leading comprehensive cancer center in France, concentrates on determiningAnimal studies conducted by the feasibilityCompany showed that local administration of our INTASYL™ platform to targetPH-894 or the TME via intra-tumoral injection. An in vivo study completed with Gustave Roussy demonstrated that an INTASYL™ compound delivered viamouse version of PH-762 through intra-tumoral injection resulted in potent anti-tumoral effects. The treated animals showed silencinga complete and statistically significant inhibition of gene expression with our INTASYL™ compounds with greater than 90% reduction of the target gene expression in a mouse model of melanoma.

Recenttumor growth, whereas placebo treated animals displayed exponential tumor growth. inIn vivostudies performed by the Company with PH-804 showed that intra-tumoral injectionsinjection of a mouse version of PH-804 reduced the tumor growth in colorectal carcinoma tumor bearing mice, which was shown to beinhibit tumor growth and was correlated with the silencing of TIGIT messenger RNA (“mRNA”) expression and anin increase in cytotoxic effector T cells in the TME.

The combined PH-804, PH-762, and PH-894 data further shows that INTASYL compounds can trigger associated changes in the TME such as an increase of TILs, including CD8+ T cells responsible for tumor cell killing, and an increase of activation markers on these cells. These preclinical findings demonstrate that direct injection of INTASYL compounds can successfully infiltrate solid tumors and impact the TME by activating the immune response in animal models of solid tumors resulting in reduced tumor growth. A key challenge for many other immunotherapy platforms is to be able to achieve an adequate therapeutic effect in solid tumors with an acceptable safety profile. Many of the available systemic immuno-therapeutics indeed come with dose limiting immune-related adverse events, which we believe can be mitigated with local INTASYL treatment.

Based on our positive preclinical data, the Company is preparing for a clinical study with PH-762 using intra-tumoral administration for patients with advanced melanoma. The required preclinical studies and steps needed to initiate the clinical trial with PH-762 as a direct therapeutic are continuing and ongoing. The clinical trial will be conducted at the Gustave Roussy Institute, which is France’s largest cancer center and Dr. Caroline Robert will be our lead principal investigator. The Company expects to move PH-762 for intra-tumoral injection intostart the clinical development stagetrial evaluating the use of PH-762 as a direct therapeutic in the fourth quarter of 2021.

We are also investigating other relevant compounds for TME targets, such as PH-790, an INTASYL compound targeting PD-L1. PD-L1 is a protein formed by cancer cells that activate the PD-1 “off switch” on immune cells. Our approach with PH-790 is to block the formation of the PD-L1 protein, which may prevent cancer cells from inactivating T cells and attack the cancer. Recent data presented demonstrated that the antitumoral efficacy of our individual pipeline products, PH-762, PH-790 and PH-804, can be further improved by combining them in a single drug treatment. We have shown that, in contrast to other technology platforms, we can efficiently target multiple proteins, in a single drug treatment without negative consequences related to the potency of the individual components. Animal data showed that the combination of our INTASYL compounds in a single formulation (at suboptimal doses of the individual agents) inhibited tumor growth without having a negative impact on the tolerability of the treatment.

Our INTASYL™INTASYL Platform

Our development efforts are based on our broadly patented INTASYL technology platform. Our INTASYL compounds do not require a delivery vehicle to penetrate into tissues and cells and are designed to “silence” or down-regulate, the expression of a specific gene which is over-expressed in cancer.

Diseases are often related to the wrong protein being made, excessive amounts of a specific protein being made, or the correct protein being made but at the wrong location or time. Overall, RNA is involved in the synthesis, regulation and processingexpression of proteins. RNA interference (“RNAi’) is a biological process in which specific RNA molecules inhibit gene expression or translation into proteins by preventing certain RNA from being read.proteins. RNAi offers a novel approach to the drug development process because RNAi compounds can potentially be designed to targetsilence any one of the thousands of human genes, many of which are “undruggable” by other modalities. SupportedThe potential of RNAi as a powerful drug development platform has been shown by numerous gene-silencing reports and our own research, we believe that this sequence information can be used to designseveral RNAi compounds to interfere withbased drugs becoming approved over the expression of almost any specific gene.last few years.

The first design of RNAi compounds to be pursued for the development of human therapeutics were short, double-stranded RNAs that included limited modifications, known as small-interfering RNA (“siRNA”). Since the initial discovery of RNAi, drug delivery has been the primary challenge in developing RNAi-based therapeutics. One conventional solution to the delivery problem involves encapsulation of siRNA into a lipid-based particle,formulations, such as a liposome,liposomes, to improve circulation time and cellular uptake. Another approach is to use chemical conjugations of a ligand, such as GalNAC, for cell specific delivery limited to hepatocytes. We have developed an alternative approach where delivery and drug-like properties are built directly into the RNAi compound itself.itself, whereby the RNAi uptake is neither dependent on complex formulation nor limited to addressing a specific cell type. These novel compounds are termed self-delivering RNAi compounds, or INTASYL™.INTASYL.

Our INTASYL™INTASYL compounds are hybrid oligonucleotide compounds that the Company believes combines the beneficial properties of both conventional RNAi and antisense technologies. Traditional, single-stranded antisense compounds have favorable tissue distribution and cellular uptake properties. However, they do not have the intracellular potency that is a hallmark of double-stranded RNAi compounds. Conversely, the duplex structure and hydrophilic character of traditional RNAi compounds results in poor tissue distribution and cellular uptake. In an attempt to combine the best properties of both technologies, INTASYL™INTASYL compounds have a single-stranded phosphorothioate region, a short duplex region, and contain a variety of nuclease-stabilizing and lipophilic chemical modifications. The combination of these features allows INTASYL™INTASYL compounds to achieve efficient spontaneous cellular uptake and potent, long-lasting intracellular activity.

We believe that our next generation INTASYL™ compounds offer significant advantages over siRNAs used by other companies developing RNAi therapeutics, which are highlighted by the following characteristics:

The route by which our INTASYL™ compounds are brought into contact with the body depends on the intended organ or tissue to be treated. Delivery routes can be simplified into two major categories: (1) local, or when a drug is delivered directly to the tissue of interest, and (2) systemic, when a drug accesses the tissue of interest through the circulatory system. The key to therapeutic success with RNAi lies in delivering intact RNAi compounds to the target tissue and the interior of the target cells. To accomplish this, our chemically synthesized INTASYL™INTASYL compounds are optimized for stability and efficacy and have unique properties that improve tissue and cell uptake.

Intellectual Property

We protect our proprietary information by means of United States and foreign patents, trademarks and copyrights. In addition, we rely upon trade secret protection and contractual arrangements to protect certain of our proprietary information and products. We have pending patent applications that relate to potential drug targets, compounds we are developing to modulate those targets, methods of making or using those compounds and proprietary elements of our drug discovery platform.

Much of our technology and many of our processes depend upon the knowledge, experience and skills of key scientific and technical personnel. To protect our rights to our proprietary know-how and technology, we require all employees, as well as our consultants and advisors when feasible, to enter into confidentiality agreements that require disclosure and assignment to us of ideas, developments, discoveries and inventions made by these employees, consultants and advisors in the course of their service to us, and we vigorously defend that position with partners, as well as with employees who leave the Company.us.

We have also obtained rights to various patents and patent applications under licenses with third parties, which require us to pay royalties, milestone payments, or both. The degree of patent protection for biotechnology products and processes, including ours, remains uncertain, both in the United States and in other important markets, because the scope of protection depends on decisions of patent offices, courts and lawmakers in these countries. There is no certainty that our existing patents or others, if obtained, will afford us substantial protection or commercial benefit. Similarly, there is no assurance that our pending patent applications or patent applications licensed from third parties will ultimately be granted as patents or that those patents that have been issued or are issued in the future will stand if they are challenged in court. We assess our license agreements on an ongoing basis and may from time to time terminate licenses to technology that we do not intend to employ in our technology platforms, or in our product discovery or development activities.

Patents and Patent Applications

We are actively seeking protection for our intellectual property and are prosecuting a number of patents and pending patent applications covering our compounds and technologies. A combined summary of these patents and patent applications is set forth below in the following table:

Our portfolio includes 112119 issued patents, 4566 of which cover our INTASYL™INTASYL platform. There are 16 patent families broadly covering both the composition and methods of use of our self-delivering platform technology and uses of our INTASYL™INTASYL compounds targeting immune checkpoint, cellular differentiation and metabolism targets forex vivo cell-based cancer immunotherapies. These patents are scheduled to expire between 2029 and 2038. Furthermore, there are 7167 patent applications, encompassing what we believe to be important new RNAi compounds and their use as therapeutics, chemical modifications of RNAi compounds that improve the compounds’ suitability for therapeutic uses (including delivery) and compounds directed to specific targets (i.e., that address specific disease states). The patents and any patents that may issue from these pending patent applications will, if issued, be set to expire between 2022 and 2038, not including any patent term extensions that may be afforded under the Federal Food, Drug, and Cosmetic Act (“FFDCA”) (and the equivalent provisions in foreign jurisdictions) for any delays incurred during the regulatory approval process relating to human drug products (or processes for making or using human drug products).

Option andIntellectual Property License AgreementsAgreements

Medigene AG and the Helmholtz Zentrum München.On March 6, 2020, we entered into a Collaboration and Option Agreement (the “Collaboration Agreement”) with Medigene AG andthe Helmholtz Zentrum München (“HMGU”). The Collaboration Agreement expands upon the Company’s outstanding research agreement with HMGU to design and develop novel candidates for the use of INTASYL™ compounds in ACT to enhance immune cell function. Under the Collaboration Agreement, Medigene will contribute expertise regarding clinical development, as well as proprietary research material, and has an option to an exclusive license for the clinical and/or commercial exploitation of the potential immune cell enhancers against certain fee payments.

We have secured exclusive and non-exclusive rights to develop therapeutics by licensing key RNAi technologies and patent rights from third parties. These rights relate to chemistry and configuration of compounds, delivery technologies of compounds to cells and therapeutic targets. As we continue to develop our own proprietary compounds, we continue to evaluate both our in-licensed portfolio as well as the field for new technologies that could be in-licensed to further enhance our intellectual property portfolio and unique position in the RNAi and immuno-oncology space.intellectual property position.

Advirna LLC. InOn September 24, 2011, we entered into an agreement with Advirna, LLC (“Advirna”) pursuant to which Advirna assigned to us its existing patent and technology rights related to the INTASYL™INTASYL technology in exchange for our agreement to issueand we granted back to Advirna a license for use of the assigned patent and technology rights outside of human therapeutics and diagnostics. Under the terms of the agreement, in April 2012, the Company issued to Advirna shares of common stock equal to 5% of the Company’s fully-diluted shares payoutstanding at the time of issuance and paid a one-time milestone payment of $350,000 in 2014 upon the issuance of the first patent under the agreement. The Company also pays to Advirna an annual maintenance fee of $100,000 and pay a one-time milestone payment of $350,000 upon the issuance of the first patent with valid claims covering the assigned technology. The common shares of the Company were issued to Advirna in 2012 upon the completion of the spin-out from our former parent company and the one-time milestone payment was paid in 2014. Additionally, we will beis required to pay a 1% royalty to Advirnalow single-digit royalties on any license revenue received by usthe Company with respect to future licensing of the assigned Advirna patent and technology rights. To date, royalties owed to Advirna under the agreement have been minimal. We also granted back to Advirna a license under the assigned patent and technology rights for fields of use outside human therapeutics and diagnostics.

Our rights under the Advirna agreement will expire upon the later of: (i) the expiration of the last-to-expire of the “patent rights” (as defined therein) or (ii) the abandonment of the last-to-be abandoned of such patents, unless earlier terminated in accordance with the provisions of the agreement.

We may terminate the Advirna agreement at any time upon 90 days’ written notice to Advirna, and Advirna may terminate the agreement upon 90 days’ prior written notice in the event that we cease using commercially reasonable efforts to research, develop, license or otherwise commercialize the patent rights or “royalty-bearing products” (as defined therein), provided that we may refute such claim within such 90-day period by showing budgeted expenditures for the research, development, licensing or other commercialization consistent with other technologies of similar stage of development and commercial potential as the patent rights or royalty-bearing products. Further, either party at any time may provide to the other party written notice of a material breach of the agreement. If the other party fails to cure the identified breach within 90 days after the date of the notice, the aggrieved party may terminate the agreement by written notice to the party in breach.

Legacy Dermatology and Ophthalmology Programs

In January 2018, the Company announced that it was exploring strategic alternatives, including a potential sale or out-license, with respect to the Company’s legacy dermatology and ophthalmology programs following the Company’s change in strategic direction to focus solely on immuno-oncology. Due to resource constraints, the Company has significantly reduced its efforts to out-license or sell these programs and does not expect to provide further updates on these assets going forward.

Research and Development

Our research and development expense primarily consists of compensation and benefits for research and development personnel, facility-related expenses, supplies, external services, costs to acquire technology licenses, expenses associated with preclinical and clinical development activities and other operating costs.

Total research and development expense for the years ended December 31, 2020 and 2019 was $4,431,000 and 2018 was $4,300,000, and $4,326,000, respectively.

Competition

The biotechnology and pharmaceutical industries, including the immuno-oncology field, are a constantly evolving landscape with rapidly advancing technologies and significant competition. There are a number of competitors in the immuno-oncology field including large and small pharmaceutical and biotechnology companies, academic institutions, government agencies and other private and public research organizations.

A variety of cell-based autologous and allogeneic approaches are being researched and developed, including but not limited to: CAR-T cells, TCR-T cells, Gamma Delta T cells, CAR-NK cells, NK cells, NKT cells and cytotoxic T cells. We believe that competitors in this field include, but are not limited to: Achilles Therapeutics UK Ltd., Adicet Bio, Inc., AgonOx, Inc., Allogene Therapeutics, Inc., Atara Biotherapeutics, Inc., Autolus Therapeutics plc, Baylor College of Medicine, Bellicum Pharmaceuticals, Inc., bluebird bio, Inc., Celyad S.A., Celgene Corporation, Cell Medica Ltd., Cellectis S.A., Celularity, Inc., CiMaas B.V., CRISPR Therapeutics AG, Fate Therapeutics, Inc., Formula Therapeutics, Inc., Fortress Biotech, Inc., GAIA Biomedicine Inc., Glycostem Therapeutics BV, Green Cross LabCell Corp., Immatics Biotechnologies GmbH, Iovance Biotherapeutics, Inc., Intrexon Corporation, Janssen Biotech, Inc., Kite Pharma, Inc.(a Gilead company), Medigene AG, Mustang Bio, Inc., NantKwest, Inc., BioNTech NE, Novartis International AG, Precigen, Inc., Refuge Biotechnologies, Inc., Sorrento Therapeutics, Inc., Tactiva Therapeutics, Inc., TC BioPharm Limited, Turnstone Biologics Corp. and Ziopharm Oncology, Inc.

A number of technological approaches to modulating gene expression in the field of immuno-oncology have been identified and are being researched and developed, including but not limited to: antisense oligodeoxynucleotides, RNAi, zinc-finger nucleases, transcription activator-like effector nucleases, mRNA, and genetic engineering techniques such as clustered regularly interspaced short palindromic repeats, or CRISPR, and various others. We believe that competitors in this field include, but are not limited to: Avidity Biosciences, BioNTech NE, Cellectis S.A., CRISPR Therapeutics AG, Dicerna Pharmaceuticals, Inc., Editas Medicine, Inc., eTheRna immunotherapies NV, Exicure Inc., Horizon Discovery Group plc, Intellia Therapeutics, Inc., Kymera Therapeutics Inc., miRagen Therapeutics, Inc., Moderna, Inc., Noxxon Pharma N.V., Obsidian Therapeutics, Inc., OliPass Corporation, OncoSec Medical Incorporated, Mateon Therapeutics, Inc., PTC Therapeutics, Inc., Sangamo Therapeutics, Inc., Sirnaomics, Inc., Stemirna Therapeutics Co., Ltd. and Takara Bio Inc.

Government Regulation

The United States and many other countries extensively regulate the preclinical and clinical testing, manufacturing, labeling, storage, record-keeping, advertising, promotion, export, marketing and distribution of drugs and biologic products. The U.S. Food and Drug Administration (“FDA”) regulates pharmaceutical and biologic products under the FFDCA, the Public Health Service Act and other federal statutes and regulations.

To obtain approval of our future product candidates from the FDA, we must, among other requirements, submit data supporting safety and efficacy for the intended indication as well as detailed information on the manufacture and composition of the product candidate. In most cases, this will require extensive laboratory tests and preclinical and clinical trials. The collection of these data, as well as the preparation of applications for review by the FDA involve significant time and expense. The FDA also may require post-marketing testing to monitor the safety and efficacy of approved products or place conditions on any approvals that could restrict the therapeutic claims and commercial applications of these products. Regulatory authorities may withdraw product approvals if we fail to comply with regulatory standards or if we encounter problems at any time following initial marketing of our products.

The first stage of the FDA approval process for a new biologic or drug involves completion of preclinical studies and the submission of the results of these studies to the FDA. These data, together with proposed clinical protocols, manufacturing information, analytical data and other information submitted to the FDA in an investigational new drug (“IND”) application, must become effective before human clinical trials may commence. Preclinical studies generally involve FDA regulated laboratory evaluation of product characteristics and animal studies to assess theefficacy and safety of the product candidate.

After the IND becomes effective, a company may commence human clinical trials. These are typically conducted in three sequential phases, but the phases may overlap. Phase 1 trials consist of testing the product candidate in a small number of patients or healthy volunteers, primarily for safety at one or more doses. Phase 2 trials, in addition to safety, evaluate the efficacy of the product candidate in a patient population somewhat larger than Phase 1 trials. Phase 3 trials typically involve additional testing for safety and clinical efficacy in an expanded population at multiple test sites. A company must submit to the FDA a clinical protocol, accompanied by the approval of the Institutional Review Board (“IRB”) at the institutions participating in the trials, prior to commencement of each clinical trial.

To obtain FDA marketing authorization, a company must submit to the FDA the results of the preclinical and clinical testing, together with, among other things, detailed information on the manufacture and composition of the product candidate, in the form of a new drug application (“NDA”), or, in the case of a biologic, a biologics license application (“BLA”).

The amount of time taken by the FDA for approval of an NDA or BLA will depend upon a number of factors, including whether the product candidate has received priority review, the quality of the submission and studies presented, the potential contribution that the compound will make in improving the treatment of the disease in question and the workload at the FDA.

The FDA may, in some cases, confer upon an investigational product the status of a fast track product. A fast track product is defined as a new drug or biologic intended for the treatment of a serious or life-threatening condition that demonstrates the potential to address unmet medical needs for this condition. The FDA can base approval of an NDA or BLA for a fast track product on an effect on a surrogate endpoint, or on another endpoint that is reasonably likely to predict clinical benefit. If a preliminary review of clinical data suggests that a fast track product may be effective, the FDA may initiate review of entire sections of a marketing application for a fast track product before the sponsor completes the application.

We anticipate that our products will be manufactured by our strategic partners, licensees or other third parties. Before approving an NDA or BLA, the FDA will inspect the facilities at which the product is manufactured and will not approve the product unless the manufacturing facilities are in compliance with the FDA’s current good manufacturing practice regulations (“cGMP”), which are regulations that govern the manufacture, holding and distribution of a product. Manufacturers of biologics also must comply with the FDA’s general biological product standards. Our manufacturers also will be subject to regulation under the Occupational Safety and Health Act, the Nuclear Energy and Radiation Control Act, the Toxic Substance Control Act and the Resource Conservation and Recovery Act and other applicable environmental statutes. Following approval, the FDA periodically inspects drug and biologic manufacturing facilities to ensure continued compliance with the cGMP. Our manufacturers will have to continue to comply with those requirements. Failure to comply with these requirements subjects the manufacturer to possible legal or regulatory action, such as suspension of manufacturing or recall or seizure of product. Adverse patient experiences with the product must be reported to the FDA and could result in the imposition of marketing restrictions through labeling changes or market removal. Product approvals may be withdrawn if compliance with regulatory requirements is not maintained or if problems concerning safety or efficacy of the product occur following approval.

The labeling, advertising, promotion, marketing and distribution of a drug or biologic product also must be in compliance with FDA and Federal Trade Commission requirements which include, among others, standards and regulations for off-label promotion, industry sponsored scientific and educational activities, promotional activities involving the internet, and direct-to-consumer advertising. We also will be subject to a variety of federal, state and local regulations relating to the use, handling, storage and disposal of hazardous materials, including chemicals and radioactive and biological materials. In addition, we will be subject to various laws and regulations governing laboratory practices and the experimental use of animals. In each of these areas, as above, the FDA has broad regulatory and enforcement powers, including the ability to levy fines and civil penalties, suspend or delay issuance of product approvals, seize or recall products and deny or withdraw approvals.

We will also be subject to a variety of regulations governing clinical trials and sales of our products outside the United States. Whether or not FDA approval has been obtained, approval of a product candidate by the comparable regulatory authorities of foreign countries and regions must be obtained prior to the commencement of marketing the product in those countries. The approval process varies from one regulatory authority to another and the time may be longer or shorter than that required for FDA approval. In the European Union, Canada and Australia, regulatory requirements and approval processes are similar, in principle, to those in the United States.

Environmental Compliance

Our research and development activities involve the controlled use of potentially harmful biological materials as well as hazardous materials, chemicals and various radioactive compounds. We are subject to federal, state and local laws and regulations governing the use, storage, handling and disposal of these materials and specific waste products. We are also subject to numerous environmental, health and workplace safety laws and regulations, including those governing laboratory procedures, exposure to blood-borne pathogens and the handling of bio-hazardous materials. The cost of compliance with these laws and regulations could be significant and may adversely affect capital expenditures to the extent we are required to procure expensive capital equipment to meet regulatory requirements.

Employees

Human Capital Management

As of March 20,December 31, 2020, we had eleventen full-time employees.employees at our facility in Marlborough, Massachusetts. None of our employees are represented by a labor union or covered by a collective bargaining agreement nor have we experienced any work stoppages.

We expect to add additional employees in fiscal year 2021 to increase our expertise and resources available in our preclinical and clinical research and development. We continually evaluate our business needs and weigh the use of in-house expertise and capacity with outsourced expertise and capacity. The Company currently outsources substantial preclinical and clinical trial work to third party contract research organizations and drug manufacturing contractors.

Our ability to identify, attract, retain and integrate additional qualified key personnel is also critical to our success and the competition for skilled research, product development, regulatory and technical personnel is intense. To attract qualified applicants to the Company, we offer a total rewards package consisting of base salary and cash target bonus based on geography and size of company, a comprehensive benefit package and equity compensation for every employee. Bonus opportunity and equity compensation increase as a percentage of total compensation based on level of responsibility. Actual bonus payout is based on performance.

A large majority of Phio’s employees have obtained advanced degrees in their professions and we support our employees’ further development with individualized development plans, mentoring, coaching, group training, conference attendance and financial support including tuition reimbursement.

Corporate Information

On January 10, 2020, the Board of Directors of the Company approved a 1-for-55 reverse stock split of the Company’s outstanding common stock, which was effected on January 15, 2020. All share and per share amounts have been adjusted to give effect to the reverse stock split.

We were incorporated in the state of Delaware in 2011 as RXi Pharmaceuticals Corporation. On November 19, 2018, the Company changed its name to Phio Pharmaceuticals Corp., to reflect its transition from a platform company to one that is fully committed to developing groundbreaking immuno-oncology therapeutics. Our executive offices are located at 257 Simarano Drive, Suite 101, Marlborough, MA 01752, and our telephone number is (508) 767-3861.

The Company’s website address ishttp://www.phiopharma.com. We make available on our website, free of charge, copies of our annual reports on Form 10-K, our quarterly reports on Form 10-Q and our current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, (the “Exchange Act”) as soon as reasonably practicable after these reports are filed electronically with, or otherwise furnished to, the Securities and Exchange Commission (the “SEC”). We also make available on our website the charters of our audit committee, compensation committee and nominating and corporate governance committee, as well as our corporate code of ethics and conduct.

You may read and copy any materials the Company files with the SEC at the SEC’s Public Reference Room at 100 F Street, NE, Washington, DC 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC maintains an Internet site that contains reports, proxy and information statements, and other information regarding Phio and other issuers that file electronically with the SEC. The SEC’s website address ishttp://www.sec.gov. The contents of these websites are not incorporated by reference into this report and should not be considered to be part of this report.

Risks Relating to Our Business and Industry

Our business and operations may be materially and adversely affected by the recent coronavirus outbreak.pandemic.

In December 2019, a novel strain of coronavirus that causes COVID-19 was reported to have surfaced in Wuhan, China and has since spread to other parts of the world, including the United States and Europe.States. In March 2020, the World Health Organization declared the outbreak a pandemic. The coronavirus pandemic is affecting the United States and global economies.economies and as a result, government authorities have implemented restrictions and limited certain operations, such as limits on the number of people at a gathering, travel restrictions and stay-at-home orders, to try to slow the spread of coronavirus. The Company’s facilities remain operational and are operating in accordance with federal and state governmental authority guidelines and with the implementation of safety measures such as social distancing protocols, suspending travel, the wearing of masks and frequently disinfecting our workspaces. Employee personnel who do not need to be physically present on our premises are continuing to work remotely, but have the ability to be on site as required. While the majority of these mandates have specific end dates, they may be modified or extended and as a result there is uncertainty regarding the length of time that such measures will be place. We believe the impact to our internal operations has not been material thus far, however, current and future restrictions may further impact our operations and may slow or diminish our research and development activities.

As a result of the coronavirus pandemic, certain of our third-party suppliers and service providers on which we rely have seen impacts to their operations. If the outbreak continuesimpact to spread,their operations continue or extend, it may in turn affect our operations. The Company does not expect a material impact to its program’s anticipated timelines as a result of potential delays from our third-party service providers and believes that we have a sufficient supply of our INTASYL compounds to conduct our ongoing preclinical studies and initial clinical activities. However, the Company’s operations and those ofultimate impact to the third parties on which we rely is highly uncertain and subject to change. If the Company relies, including causing disruptionsmeasures to contain the outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in the supply of the Company’s product candidates and the conduct of current and plannedturn slow or delay our preclinical and clinical studies. We may need to limit operations activities, and/or implement limitations, and may experience limitationsresult in employee resources. There are risks that it may be more difficult to contain if the outbreak reaches a larger population or broader geography, in which case the risks described herein could be elevated significantly.higher costs. The extent to which the coronavirus pandemic impacts our results will depend on future developments, which are highly uncertain and cannot be predicted, including new information which may emerge concerning the severity of the coronavirus and the actions to contain the coronavirus or treat its impact, among others.

Additionally, while the potential economic impact brought by, and the duration of, the coronavirus pandemic is difficult to assess or predict, the impact of the coronavirus pandemic on the global financial markets may reduce the Company’s ability to access capital which couldand negatively impact the Company’s short-termaffect our future liquidity.

The coronavirus pandemic continues to evolve and long-term liquidity and the Company’s ability to complete its preclinical studies on a timely basis, or at all. For instance, our preclinical and clinical may be temporarily delayed or paused, and the operations of our contracted third parties may be significantly delayed as well.change rapidly. The ultimate impact of the coronavirus pandemic, or a similar public health emergency, is highly uncertain and subject to change. The Company does not yet know the full extent of potential delays or impacts on its business, financing oractivities, preclinical andstudies, clinical trial activities or the global economy as a whole. However, these effects could have a material impact on the Company’s liquidity, capital resources,results of operations and business and those of the third parties on which we rely.financial condition.

Our product candidates are in an early stage of development and may fail or experience significant delays or may never advance to the clinic, which may materially and adversely impact our business.

All of our pipeline programs are currently in the preclinical development stage and our future success heavily depends on the successful development of our INTASYL™INTASYL product candidates, which may never occur. These product candidates could be delayed, not advance into the clinic or unexpectedly fail at any stage of development. Before we can commence clinical trials for a product candidate, we must conduct extensive preclinical and other non-clinical tests in order to support an IND application, including IND-enabling good laboratory practice (“GLP”) toxicology studies, in the United States or their equivalents with regulatory authorities in other jurisdictions. Preclinical studies and clinical trials are expensive, difficult to design and can take many years. There is no assurance that we will be able to successfully develop our product candidates, and we may focus our efforts and resources on product candidates that may prove to be unsuccessful.

We cannot be certain of the outcome of preclinical testing and clinical studies and results from these studies may not predict the results that will be obtained in later phase trials of our product candidates. Even if we are able to complete our preclinical studies and planned clinical trials in line with our projected timelines, results from such studies and trials may be not replicated in subsequent preclinical studies or clinical trial results. Additionally, such studies may be delayed due to events beyond our control including as a result of natural disasters, epidemics or pandemic outbreaks such as the novel coronavirus. Further,coronavirus pandemic. While the steps for us to initiate our clinical trials with PH-762 in the second half of 2021 are continuing and ongoing, the FDA, or equivalent regulatory authority, may not accept the results of our preclinical studies or proposed clinical study designs and may require the Company to complete additional preclinical studies or impose stricter approval conditions than we expect. As a result, we cannot guarantee that we will be able to submit INDs, or similar applications, within our projected timelines, if at all, or that the FDA, or similar regulatory authorities, will allow us to commence clinical trials.

We are dependent on collaboration partners for the successful development of our adoptive cell therapy product candidates.

We are not a cell therapy company and expect to depend on third-party collaborators to support the clinical development of our ACT product candidates. We have entered into a clinical collaboration development agreement with AgonOx, Inc. for the clinical development of our PH-762 product candidate in ACT and have entered into research agreements with our academic and industry collaborators, each of which is terminable by the relevant party at any time, subject to applicable notice periods. WeThe success of our collaborations depends upon the efforts of our collaboration partners, and their performance in achieving the development activities to the extent they are responsible under our collaboration agreements. Each of our partners may not be successful in performing these activities, including completing the required preclinical studies and other information to be included in an IND application (or foreign equivalent), obtaining approval to initiate clinical trials, conducting the necessary clinical trials and arranging for the manufacturing or contract research organization (“CRO”) relationships and obtaining marketing authorization. Our partners work with other companies, potentially including some of our competitors, and their corporate objectives may not align with ours, they may change their strategic focus or pursue alternative technologies. If our collaborations are not successful or a partner terminates our collaboration agreement, our business, financial condition, results of operations could be materially and adversely affected.

Further, we may not be successful in negotiating agreements with these collaborators to continueor with future collaborators for the development and commercialization of our ACT product candidates through collaborations such as joint development or licensing agreements. Our ability to successfully negotiate such agreements will depend on, among other things, potential partners’ evaluation of the superiority of our technology over competing technologies, the quality of preclinical data that we have generated, the perceived risks specific to developing our product candidates and our partners’ own strategic and corporate objectives. If we fail to negotiate these agreements, we may not be able commence clinical trials with our ACT product candidates or we may be required to obtain licenses from third-party cell therapy companies and our business, financial condition, results of operations and prospects could be materially and adversely affected.

We rely upon third-party relationships to conduct preclinical studies, and any future clinical trials, for our product candidates and may not be able to establish or maintain the third-party relationships that are necessary to support their development.

We depend upon third-party contract research organizations (“CROs,”), medical institutions, clinical investigators, consultants and other third parties to support our preclinical research efforts such as through managing and conducting research studies, formulating our product candidates and manufacturing our product candidates and expect to rely on the same for our future clinical trials. Because we rely on these third parties, we cannot necessarily control the timing, quality of work or amount of resources that our contract partners will devote to these activities and we cannot guarantee that these parties will fulfill their obligations to us under these arrangements. Furthermore, we compete with many other companies for the resources of these third parties, some of which may be our competitors, and may detract from our programs. Additionally, as a result of the coronavirus pandemic, certain of our contracted CROs and other third parties we rely upon may be impacted by the coronavirus outbreak,are now facing impacts to their operations, resulting in delays or interruptions, interruptions. We previously had been able to engage with third-party service providers in areas with limited or no impact (e.g. countries with limited or no restrictions), but with the global spread of the virus and associated restrictions, this has been no longer possible. The Company has also undertaken efforts to mitigate potential future impact by identifying and engaging alternative third-party service providers and suppliers. However, the ultimate impact to the third parties on which we rely is highly uncertain and subject to change. If the measures to contain the coronavirus outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in turn slow or delay our preclinical and clinical activities, and/or result in higher costs. If these third parties do not successfully carry out their responsibilities, as well as within a timely fashion, our preclinical and clinical development may be delayed, unsuccessful or otherwise adversely affected.

We cannot guarantee that we will be able to successfully negotiate agreements with or maintain relationships with these third parties on favorable terms, if at all. If we are unable to obtain or maintain these agreements, we may not be able to develop, formulate, manufacture, obtain regulatory approval(s) or commercialize our product candidates. The third parties whom we rely on generally may terminate their agreements with us at any time, subject to applicable notice periods, and we may not be able to readily terminate any such agreements with contract partners even if such partners do not fulfill their obligations to us. If we have to enter into alternative arrangements it may delay or adversely affect the development of our product candidates and our business operations.

We rely upon third parties for the manufacture of our product candidates.

We rely on third party suppliers and manufacturers to provide us with the materials and services to manufacture our INTASYL™INTASYL compounds and product candidates for certain of our preclinical research activities and expect that we will rely on them for the supply of our product candidates for our future clinical trials. While we do have in-house expertise and capacity to manufacture our INTASYL™INTASYL compounds, we do not own or lease manufacturing facilities or have our own supply source for the required materials. Accordingly, we will be dependent upon third party suppliers and our contract manufacturers to obtain supplies, and we will need to either develop, contract for, or otherwise arrange for the necessary manufacturers for these supplies. If for any reason we are unable to obtain the supplies for our INTASYL™INTASYL compounds from our current manufacturer, we would have to seek to obtain it from another major manufacturer. There is no assurance that we will be able to timely secure needed supply arrangements on satisfactory terms, or at all.

Although we have used multiple contract manufacturers, weWe currently contract with only one manufacturermultiple manufacturers for the supply of our clinical product candidates. Therecandidates to reduce the risk of supply interruption or availability. However, there is no assurance that our supply of our clinical drug product will not be limited, interrupted, of satisfactory quality or be available at acceptable prices. If for any reason we are unable to obtain the clinical supply of our product candidates from our current manufacturer,manufacturers, we would have to seek to contract with another major manufacturer. While we believe that we currently have sufficient supply of our PH-762 product candidate forINTASYL compounds to conduct our plannedongoing preclinical studies and initial clinical studies,activities, we have begun to see some of our other product candidates orthird-party supplies on which we rely becoming impacted from the materials contained therein, may come from facilities in areas impacted by the coronavirus pandemic, which may result in delays or shortages due to ongoing efforts to address the outbreak.pandemic. The Company has also undertaken efforts to mitigate potential future impact by identifying and engaging alternative third-party suppliers and manufacturers. However, the ultimate impact to these third parties on which we rely is highly uncertain and subject to change. If the measures to contain the outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in turn slow or delay our preclinical and clinical activities, and/or result in higher costs. Our failure to secure these arrangements as needed could have a material adverse effect on our ability to complete the development of our clinical product candidates or, if we obtain regulatory approval, to commercialize them.

The FDA, or equivalent regulatory authority, governs the manufacturing process for product candidates and will inspect the facilities at which the product manufactured. Approval of the product will not occur unless the manufacturing facilities are in compliance with the FDA’s cGMP regulations, or equivalent foreign authority. If our suppliers or manufacturers do not comply with the FDA or foreign regulations for our product candidates, we may experience delays in timing or supply, be forced to manufacture our product candidates ourselves or seek to enter contract with another supplier or manufacturer. If we are required to switch suppliers or manufacturers, we will be required to verify that the new supplier or manufacturer maintains facilities and processes in line with cGMP regulations, which may result in delays, additional expenses, and may have a material adverse effect on our ability to complete the development of our product candidates.

Natural disasters, epidemic or pandemic disease outbreaks, trade wars, political unrest or other events could disrupt our business or operations or those of our development partners, manufacturers, regulators or other third parties with whom we conduct business now or in the future.

A wide variety of events beyond our control, including natural disasters, epidemic or pandemic disease outbreaks (such as the recent novel coronavirus outbreak)pandemic), trade wars, political unrest or other events could disrupt our business or operations or those of our manufacturers, regulatory authorities, or other third parties with whom we conduct business. These events may cause businesses and government agencies to be shut down, supply chains to be interrupted, slowed, or rendered inoperable, and individuals to become ill, quarantined, or otherwise unable to work and/or travel due to health reasons or governmental restrictions. For example, Massachusetts recently ordered most businesses closed, mandating work-from-home arrangements, where feasible, in response to the coronavirus pandemic. These limitations could negatively affect our business operations and continuity, and could negatively impact our development timelines and ability to timely perform basic business functions, including making SEC filings and preparing financial reports. If our operations or those of third parties with whom we have business are impaired or curtailed as a result of these events, the development and commercialization of our products and product candidates could be impaired or halted, which could have a material adverse impact on our business.

The approach we are taking to discover and develop novel therapeutics using RNAi may never lead to marketable products.

Our research and development efforts and our future success is based on our INTASYL™INTASYL technology platform. We plan to develop our INTASYL™INTASYL products for the treatment of cancer to be delivered via direct injection for use intratumorally and with ACT by isolating immune cells from patients, treating the cellsex vivo and then returning them to the patient for treatment. We believe that our INTASYL™INTASYL compounds may offer a new treatment option to current standards of care, such as antibodies, and potentially with a more cost-effective approach. Successful development of our INTASYL™INTASYL compounds by us, or by our collaborative partners, is highly uncertain and depends on a number of factors, many of which are beyond our control. The scientific research used to support our efforts and approach to developing RNAi therapeutics is limited. Decisions made by the Company to advance the development of our pipeline, including those related to our technology or manufacturing processes, may show to be incorrect based on further work by us or our collaborators.

The use of RNAi is a relatively new scientific discovery and the scientific evidence to support the feasibility of developing drugs based on these discoveries, or INTASYL™,INTASYL, is limited. Therefore, it is difficult to accurately predict challenges we may face with our product candidates as they move through the discovery, preclinical and clinical development stages. We may spend large amounts of money trying to develop our INTASYL™INTASYL technology and may never succeed in doing so. In addition, our research methodology bymay be unsuccessful in identifying product candidates and results from preclinical and clinical studies may not predict the results that will be obtained in later phase trials of our product candidates or our product candidates may interact with patients in unforeseen or harmful ways that may make it impractical to manufacture, market or receive regulatory approval. If we are not successful in bringing an INTASYL™INTASYL product candidate to market, it could negatively impact our business and financial condition and we may not be able to identify and successfully implement an alternative product development strategy.

A number of different factors could prevent us from advancing into clinical development, obtaining regulatory approval, and ultimately commercializing our product candidates on a timely basis, or at all. 

Before obtaining regulatory approval for the sale of any drug candidate, we must conduct extensive preclinical tests and successful clinical trials to demonstrate the safety and efficacy of our product candidates in humans. Before human clinical trials may commence, we must submit to the FDA an IND application. An IND application involves the completion of preclinical studies and the submission of the results, together with proposed clinical protocols, manufacturing information, analytical data and other data in the IND submission. The FDA may require us to complete additional preclinical studies or disagree with our clinical trial study design. Also, animal models may not exist for some of the disease areas we choose to develop our INTASYL™INTASYL product candidates for. As a result, our clinical trials may be delayed or we may be required to incur more expense than we anticipated.

Clinical trials require the review and oversight of IRBs, which approve and continually review clinical investigations and protect the rights and welfare of human subjects. Before our clinical trials can begin, we must also submit to the FDA a clinical protocol accompanied by the approval of the IRB at the institution(s) participating in the clinical trial. An inability or delay in obtaining IRB approval could prevent or delay the initiation and completion of our clinical trials, and the FDA may decide not to consider any data or information derived from a clinical investigation not subject to initial and continuing IRB review and approval.

Clinical trials of a new drug candidate require the enrollment of a sufficient number of subjects, including subjects who are suffering from the disease or condition the drug candidate is intended to treat and who meet other eligibility criteria. Rates of subject enrollment are affected by many factors, and delays in subject enrollment can result in increased costs and longer development times.With the global spread of the coronavirus and the associated safety measures to contain the spread by governmental authorities, a delay in the commencement of new clinical trials and in the enrollment and participation of patients in clinical trials may occur. The steps required for us to initiate our clinical trials with PH-762 in the second half of 2021 are continuing and ongoing, however, the Company does not yet know the full extent of potential delays or impacts related to its planned clinical activities from the coronavirus pandemic.

Clinical testing isPreclinical studies and clinical trials are lengthy and expensive, and itstheir outcome is highly uncertain. Historical failure rates are high due to number of factors, such as safety and efficacy of drug candidates. We, our collaborators, the FDA, or an IRB may suspend clinical trials of a drug candidate at any time for various reasons, including if we or they believe the subjects participating in such trials are being exposed to unacceptable health risks. Among other reasons, adverse side effects of a drug candidate on subjects in a clinical trial could result in the FDA or other regulatory authorities suspending or terminating the trial and refusing to approve a particular drug candidate for any or all indications of use.

An additional number of factors could affect the timing, cost or outcome of our drug development efforts, including the following:

A failure of any preclinical study or clinical trial can occur at any stage of testing. The results of preclinical and initial clinical testing of these products may not necessarily indicate the results that will be obtained from later or more extensive testing. Preliminary observations made in early stages of clinical trials with small numbers of subjects are inherently uncertain and initial clinical trial results are not necessarily indicative of results that will be obtained when full data sets are analyzed or in subsequent clinical trials. Because of these factors, it is difficult to predict the time and cost of the development of our product candidates. Any delay or failure in obtaining required approvals may prevent us from completing our preclinical or clinical studies and could have a material adverse effect on our ability to initiate or commercialize any drug candidate on a timely basis, or at all. Additionally, preclinical studies and clinical trials are lengthy and expensive and if our cash resources become limited we may not be able to commence, continue or complete our clinical trials.

We also are subject to numerous foreign regulatory requirements governing the conduct of clinical trials, manufacturing and marketing authorization, pricing and third-party reimbursement. The foreign regulatory approval process includes all of the risks associated with the FDA approval described above, as well as risks attributable to the satisfaction of local regulations in foreign jurisdictions. Approval by the FDA does not assure approval by regulatory authorities outside of the United States.

We are dependent on the success of our product candidates and even if we complete the necessary preclinical and clinical studies, we may not receive or be delayed in receiving regulatory approval and as a result, we will not be able to commercialize or will be delayed in commercializing our product candidates.

We have no commercial products and currently generate no revenue from product sales and may never be able to develop marketable products. The FDA or similar foreign governmental agencies must approve our products in development before they can be marketed. We, and any of our collaborators, must demonstrate and establish our product candidate’s safety, purity and effectiveness to patients through extensive clinical trials before we can submit an NDA or BLA to the FDA for approval. Even if we complete the necessary preclinical and clinical studies, it is possible that none of the product candidates that we may attempt to develop will obtain the appropriate regulatory approvals needed to begin selling them or they may be subject to limitations on the indicated uses for which we may market the product.

The process for obtaining FDA and other approval is both time consuming and costly, with no certainty of a successful outcome, and can often take years following the commencement of clinical trials, depending on the complexity of the drug candidate. Any analysis we perform of data from clinical activities is subject to confirmation and interpretation by regulatory authorities, which could delay, limit or prevent regulatory approval. The FDA has substantial discretion in the approval process and may deny our application, may decide our data is insufficient or require additional information from us regarding our current or planned clinical trials at any time, and such information may be costly to provide or cause potentially significant delays in development. Any changes in marketing approval policies or regulatory statutes and regulations during product development, trials and the review process, may cause delays in the approval of an application. There is no assurance that we will be able to successfully develop any of our product candidates, and we may spend large amounts of money trying to resolve these issues and may never succeed in doing so.

We have no experience in filing the applications necessary to obtain marketing approval and expect that we andwill need to rely on CROs and regulatory consultants to assist us with this process. Regulatory approval also requires the submission about the product manufacturing process and inspection of the manufacturing facilities, to the relevant regulatory authority. Any product candidates we develop may not be effective, may prove to have undesirable or unintended side effects, toxicities or other characteristics that may preclude our obtaining marketing approval or prevent or limit commercial use.

If we experience delays or fail to obtain marketing approval for any of our product candidates that we may develop, we would be prevented from being able to commercialize our product candidates and our commercial prospects and ability to generate revenues may be materially impaired.

The FDA could impose a unique regulatory regime for our therapeutics.

The compounds we intend to develop may represent a new class of drug, and even though the first RNAi therapeutic was approved in August 2018, the FDA has not yet established any definitive policies, practices or guidelines in relation to these drugs. While we expect any product candidates that we develop will be regulated as a new drug under the Federal Food, Drug, and Cosmetic Act, the FDA could decide to regulate them or other products we may develop as biologics under the Public Health Service Act. The lack of policies, practices or guidelines may hinder or slow review by the FDA of any regulatory filings that we may submit. Moreover, the FDA may respond to these submissions by defining requirements that we may not have anticipated.

Even if we receive regulatory approval to market our product candidates, our product candidates may not be accepted commercially, which may prevent us from becoming profitable.

Even if we receive regulatory approval for a product candidate, we may not generate or sustain revenues from sales of the product. The product candidates that we are developing are based on new technologies and therapeutic approaches, which are largely unproven. Additionally, RNAi products do not readily cross the so-called blood brain barrier, are rapidly eliminated from circulating blood and, for various applications, are likely to require injection or implantation, which will make them less convenient to administer than drugs administered orally. Key participants in the pharmaceutical marketplace, such as physicians, medical professionals working in large reference laboratories, public health laboratories and hospitals, third-party payors and consumers may not accept products intended to improve therapeutic results based on our technologies. For example, RNAi products may be more expensive to manufacture than traditional small molecule drugs, which may make them costlier than competing small molecule drugs. As a result, it may be more difficult for us to convince the medical community and third-party payors to accept and use our products or to provide favorable reimbursement. If medical professionals working with large reference laboratories, public health laboratories and hospitals choose not to adopt and use our technologies, our products may not achieve broader market acceptance.

Additionally, although we expect that we will have intellectual property protection for our technology, certain governments may elect to deny patent protection for drugs targeting diseases with high unmet medical need (e.g., as in the case of HIV) and allow in their country internationally unauthorized generic competition. If this were to happen, our commercial prospects for developing any such drugs would be substantially diminished in these countries.

We are dependent on technologies we license, and if we lose the right to license such technologies or fail to license new technologies in the future, our ability to develop new products would be harmed.

Many patents in the fields we are pursuing have already been exclusively licensed to third parties, including our competitors. If any of our existing licenses are terminated, the development of the products contemplated by the licenses could be delayed or terminated and we may not be able to negotiate additional licenses on acceptable terms, if at all, which would have a material adverse effect on our business.

We may be unable to protect our intellectual property rights licensed from other parties; our intellectual property rights may be inadequate to prevent third parties from using our technologies or developing competing products; and we may need to license additional intellectual property from others.

Therapeutic applications of gene silencing technologies, formulations, delivery methods and other technologies that we license from third parties are claimed in a number of pending patent applications, but there is no assurance that these applications will result in any issued patents or that those patents would withstand possible legal challenges or protect our technologies from competition. The United States Patent and Trademark Office and patent granting authorities in other countries have upheld stringent standards for the RNAi patents that have been prosecuted so far. Consequently, pending patents that we have licensed and those that we own may continue to experience long and difficult prosecution challenges and may ultimately issue with much narrower claims than those in the pending applications. Third parties may hold or seek to obtain additional patents that could make it more difficult or impossible for us to develop products based on our technologies without obtaining a license to such patents, which licenses may not be available on attractive terms, or at all.

In addition, others may challenge the patents or patent applications that we currently license or may license in the future or that we own and, as a result, these patents could be narrowed, invalidated or rendered unenforceable, which would negatively affect our ability to exclude others from using the technologies described in these patents. There is no assurance that these patent or other pending applications or issued patents we license or that we own will withstand possible legal challenges. Moreover, the laws of some foreign countries may not protect our proprietary rights to the same extent as do the laws of the United States. Any patents issued to us or our licensors may not provide us with any competitive advantages, and there is no assurance that the patents of others will not have an adverse effect on our ability to do business or to continue to use our technologies freely. Our efforts to enforce and maintain our intellectual property rights may not be successful and may result in substantial costs and diversion of management time. Even if our rights are valid, enforceable and broad in scope, competitors may develop products based on technology that is not covered by our licenses or patents or patent applications that we own.

There is no guarantee that future licenses will be available from third parties for our product candidates on timely or satisfactory terms, or at all. To the extent that we are required and are able to obtain multiple licenses from third parties to develop or commercialize a product candidate, the aggregate licensing fees and milestones and royalty payments made to these parties may materially reduce our economic returns or even cause us to abandon development or commercialization of a product candidate.

Our success depends upon our ability to obtain and maintain intellectual property protection for our products and technologies.

The applications based on RNAi technologies claim many different methods, compositions and processes relating to the discovery, development, delivery and commercialization of RNAi therapeutics. Because this field is so new, very few of these patent applications have been fully processed by government patent offices around the world, and there is a great deal of uncertainty about which patents will issue, when, to whom and with what claims. Although we are not aware of any blocking patents or other proprietary rights, it is likely that there will be significant litigation and other proceedings, such as interference and opposition proceedings in various patent offices, relating to patent rights in the RNAi field. It is possible that we may become a party to such proceedings.

We are subject to significant competition and may not be able to compete successfully.

The biotechnology and pharmaceutical industries, including immuno-oncology, have intense competition and contain a high degree of risk. We face a number of competitors that have substantially greater experience and greater research and development capabilities, staffing, financial, manufacturing, marketing, technical and other resources than us, and we may not be able to successfully compete with them. These companies include large and small pharmaceutical and biotechnology companies, academic institutions, government agencies and other private and public research organizations.

In addition, even if we are successful in developing our product candidates, in order to compete successfully we may need to be first to market or to demonstrate that our products are superior to therapies based on different technologies. Some of our competitors may develop and commercialize products that are introduced to market earlier than our product candidates or on a more cost-effective basis. A number of our competitors have already commenced clinical testing of product candidates and may be more advanced than we are in the process of developing products. If we are not first to market or are unable to demonstrate superiority, on a cost-effective basis or otherwise, any products for which we are able to obtain approval may not be successful.

Our competitors also compete with us in acquiring technologies complementary to our INTASYL™INTASYL technology. We may face competition with respect to product efficacy and safety, ease of use and adaptability to modes of administration, acceptance by physicians, timing and scope of regulatory approvals, reimbursement coverage, price and patent position, including dominant patent positions of others. If we are not able to successfully obtain regulatory approval or commercialize our product candidates, we may not be able to establish market share and generate revenues from our technology.

We are subject to potential liabilities from clinical testing and future product liability claims.

If any of our future products are alleged to be defective, they may expose us to claims for personal injury by subjects in clinical trials of our products. If our products are approved by the FDA, users may claim that such products caused unintended adverse effects. We will seek to obtain clinical trial insurance for clinical trials that we conduct, as well as liability insurance for any products that we market. There is no assurance that we will be able to obtain insurance in the amounts we seek, or at all. We anticipate that licensees who develop our products will carry liability insurance covering the clinical testing and marketing of those products. There is no assurance, however, that any insurance maintained by us or our licensees will prove adequate in the event of a claim against us. Even if claims asserted against us are unsuccessful, they may divert management’s attention from our operations and we may have to incur substantial costs to defend such claims.

Any drugs we develop may become subject to unfavorable pricing regulations, third-party reimbursement practices or healthcare reform initiatives, which could have a material adverse effect on our business.

If approved, we intend to sell our products primarily to hospitals, oncologists and clinics, which receive reimbursement for the healthcare services they provide to their patients from third-party payors, such as Medicare, Medicaid and other domestic and international government programs, private insurance plans and managed care programs. Most third-party payors may deny reimbursement if they determine that a medical product was not used in accordance with cost-effective treatment methods, as determined by the third-party payor, was used for an unapproved indication or if they believe the cost of the product outweighs its benefits. Third-party payors also may refuse to reimburse for experimental procedures and devices. Furthermore, because our programs are still in development, we are unable at this time to determine their cost-effectiveness and the level or method of reimbursement for them. Increasingly, the third-party payors who reimburse patients are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. If the price we are able to charge for any products we develop is inadequate in light of our development and other costs, our profitability could be adversely affected.

We currently expect that any drugs we develop may need to be administered under the supervision of a physician. Under currently applicable law, drugs that are not usually self-administered may be eligible for coverage by the Medicare program if:

Insurers may refuse to provide insurance coverage for newly approved drugs, including drugs in our clinical pipeline, or insurance coverage may be delayed or be more limited than the purpose for which the drugs are approved by the FDA. Moreover, eligibility for insurance coverage does not imply that any drug will be reimbursed in all cases or at a rate that covers our costs, including research, development, manufacture, sale and distribution costs. Interim payments for new drugs, if applicable, may also not be sufficient to cover our costs and may not be made permanent. Reimbursement may be based on payments for other services and may reflect budgetary constraints or imperfections in Medicare data. Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement rates. Our inability to promptly obtain coverage and profitable reimbursement rates from both government-funded and private payors for new drugs that we develop could have a material adverse effect on our operating results, our ability to raise capital needed to develop products and our overall financial condition.

Additionally, third-party payors are increasingly attempting to contain healthcare costs by limiting both coverage and the level of reimbursement for medical products and services. Levels of reimbursement may decrease in the future, and future legislation, regulation or reimbursement policies of third-party payors may adversely affect the demand for and price levels of our products. If our customers are not reimbursed for our products, they may reduce or discontinue purchases of our products, which could have a material adverse effect on our business, financial condition and results of operations.

Comprehensive healthcare reform legislation, which became law in 2010, and any revisions to this legislation, could adversely affect our business and financial condition. Among other provisions, the legislation provides that a “biosimilar” product may be approved by the FDA on the basis of analytical tests and certain clinical studies demonstrating that such product is highly similar to an existing, approved product and that switching between an existing product and the biosimilar product will not result in diminished safety or efficacy. This abbreviated regulatory approval process may result in increased competition if we are able to bring a product to market. The legislation also includes more stringent compliance programs for companies in various sectors of the life sciences industry with which we may need to comply and enhanced penalties for non-compliance with the new healthcare regulations. Complying with new regulations may divert management resources, and inadvertent failure to comply with new regulations may result in penalties being imposed on us.

Some states and localities have established drug importation programs for their citizens, and federal drug import legislation has been introduced in Congress. The Medicare Prescription Drug Plan legislation, which became law in 2003, required the Secretary of Health and Human Services to promulgate regulations for drug reimportation from Canada into the United States under some circumstances, including when the drugs are sold at a lower price than in the United States. The Secretary, however, retained the discretion not to implement a drug reimportation plan, if the Secretary finds that the benefits do not outweigh the costs, and has so far declined to approve a reimportation plan. Proponents of drug reimportation may attempt to pass legislation that would directly allow reimportation under certain circumstances. Legislation or regulations allowing the reimportation of drugs, if enacted, could decrease the price we receive for any products that we may develop and adversely affect our future revenues and prospects for profitability.

With the current U.S. administration and Congress, there may be additional legislative changes, including repeal and replacement of certain provisions of the Affordable Care Act. It remains to be seen, however, precisely what new legislation will provide, when it will be enacted and what impact it will have on the availability of healthcare and containing or lowering the cost of healthcare. Such reforms could have an adverse effect on anticipated revenue from product candidates that we may successfully develop and for which we may obtain marketing approval and may affect our overall financial condition and ability to develop product candidates.

Even if we obtain regulatory approvals, our marketed drugs will be subject to ongoing regulatory review. If we fail to comply with continuing U.S. and foreign regulations, we could lose our approvals to market drugs and our business would be materially and adversely affected.

Following regulatory approval of any drugs we may develop, we will remain subject to continuing regulatory review, including the review of adverse drug experiences and clinical results that are reported after our drug products are made available to patients. This would include results from any post-marketing tests or vigilance required as a condition of approval. The manufacturer and manufacturing facilities we use to make any of our drug products will also be subject to periodic review and inspection by the FDA. The discovery of any new or previously unknown problems with the product, manufacturer or facility may result in restrictions on the drug or manufacturer or facility, including withdrawal of the drug from the market. We would continue to be subject to the FDA requirements governing the labeling, packaging, storage, advertising, promotion, recordkeeping and submission of safety and other post-market information for all of our product candidates, even those that the FDA had approved. If we fail to comply with applicable continuing regulatory requirements, we may be subject to fines, suspension or withdrawal of regulatory approval, product recalls and seizures, operating restrictions and other adverse consequences.

If we fail to attract, hire and retain qualified personnel, we may not be able to design, develop, market or sell our products or successfully manage our business.

Our business prospects are dependent on the principal members of our executive team, the loss of whose services could make it difficult for us to manage our business successfully and achieve our business objectives. While we have entered into employment agreements with each of our executive officers, they could leave at any time, in addition to our other employees, who are all “at will” employees. Our ability to identify, attract, retain and integrate additional qualified key personnel is also critical to our success. Competition for skilled research, product development, regulatory and technical personnel is intense, and we may not be able to recruit and retain the personnel we need. The loss of the services of any key research, product development, regulatory and technical personnel, or our inability to hire new personnel with the requisite skills, could restrict our ability to develop our product candidates.

Risks Relating to Our Financial Condition

We may not be ablehave a history of net losses, and we expect to obtain sufficient financingcontinue to incur net losses for the foreseeable future and may not be able to develop our product candidates.achieve or maintain profitability.

We believe that our existing cash at December 31, 2019, and the proceeds received from our capital raises completed in February 2020, will be sufficient to fund our currently planned operations for at least the next 12 months from the date this Annual Report on Form 10-K is filed. However, we have generated significant losses to date, have not generated any product revenue and may not generate product revenue in the foreseeable future, or ever. We expect to incur significant operating losses as we advance our product candidates through drug development and the regulatory process. In the future,Our ability to achieve profitability, if ever, will depend on, among other things, us or our collaborators, obtaining regulatory approvals and successfully commercializing our drug candidates. Even if we are able to successfully commercialize our drug candidates, we may not be able to achieve or sustain profitability, which could have a material adverse effect on our business, financial condition and results of operations.

We will require substantial additional funds to complete our research and development activities.

We have used substantial funds to develop our product candidates and will need to issue equity or incur debt in orderraise additional substantial funds to continue our drug development efforts and support our operations. Based on our current operating plans and liquidity, we believe that our existing cash at December 31, 2020 and the proceeds received from our capital raise activities subsequent to the balance sheet date, will be sufficient to fund our currently planned expenditures, as well asoperations for at least the next 12 months from the date of release of the associated financial statements. However, our future capital requirements and the period for which our existing resources are able to make acquisitions and other investments. We cannot assure you that equity or debt financing will be available to us on acceptable terms, or at all. Ifsupport our operations may vary significantly from what we cannot, or are limited in the ability to, issue equity, incur debt or enter into strategic collaborations, we may be unable to fund the discovery and development of our product candidates, address gaps in our product offerings or improve our technology.

expect. We anticipate that we will need to raise substantial amounts of money to fund a variety of future activities integral to the development of our business, which may include but is not limited to the following:

In the future, we will need to obtain funding from third parties, such as proceeds from the issuance of debt, sale of equity or strategic opportunities in order to fund our planned expenditures, as well as to make acquisitions and other investments. Historically, the Company’s primary source of funding has been through the sale of its securities. We cannot assure you that equity or debt financing will be available to us on acceptable terms, or at all. If we cannot, or are limited in the ability to, issue equity, incur debt or enter into strategic collaborations, we may be unable to fund the discovery and development of our product candidates, address gaps in our product offerings or improve our technology. Moreover, the global coronavirus pandemic has led to significant uncertainty and increased volatility in the capital markets. If these conditions in the capital markets continue for an extended period of time it may impact our ability to raise capital. If we fail to obtain additional funding when needed, we may ultimately be unable to continue to develop and potentially commercialize our product candidates, and we may be forced to scale back or terminate our operations or seek to merge with or be acquired by another company.

Future financing may be obtained through, and future development efforts may be paid for by, the issuance of debt or equity, which may have an adverse effect on our stockholders or may otherwise adversely affect our business.

If we raise funds through the issuance of debt or equity, any debt securities or preferred stock issued will have rights, preferences and privileges senior to those of holders of our common stock in the event of a liquidation. In such event, there is a possibility that once all senior claims are settled, there may be no assets remaining to pay out to the holders of common stock. In addition, if we raise funds through the issuance of additional equity, whether through private placements or public offerings, such an issuance would dilute current stockholders’ ownership in us.

The terms of debt securities may also impose restrictions on our operations, which may include limiting our ability to incur additional indebtedness, to pay dividends on or repurchase our capital stock, or to make certain acquisitions or investments. In addition, we may be subject to covenants requiring us to satisfy certain financial tests and ratios, and our ability to satisfy such covenants may be affected by events outside of our control.

We expect to continue to incur significant research and development expenses, which may make it difficult for us to attain profitability, and may lead to uncertainty as to our ability to continue as a going concern.

We expend substantial funds to develop our technologies, and additional substantial funds will be required for further research and development, including preclinical testing and clinical trials of any product candidates, and to manufacture and market any products that are approved for commercial sale. Because the successful development of our products is uncertain, we are unable to precisely estimate the actual funds we will require to develop and potentially commercialize them. In addition, we may not be able to generate enough revenue, even if we are able to commercialize any of our product candidates, to become profitable.

If we are unable to achieve or sustain profitability or to secure additional financing, we may not be able to meet our obligations as they come due, raising substantial doubts as to our ability to continue as a going concern. Any such inability to continue as a going concern may result in our common stockholders losing their entire investment. There is no guarantee that we will become profitable or secure additional financing. Our financial statements do not include any adjustments to, or classification of, recorded asset amounts and classification of liabilities that might be necessary if we were unable to continue as a going concern. Changes in our operating plans, our existing and anticipated working capital needs, the acceleration or modification of our expansion plans, increased expenses, potential acquisitions or other events will all affect our ability to continue as a going concern.

Our ability to utilize net operating loss carryforwards and other tax benefits may be limited.

We have historically incurred net losses. Under the Internal Revenue Code of 1986, as amended (the “Code”), a corporation is generally allowed a deduction for net operating losses carried forward from a prior taxable year. Under that provision, we can carryforward our net operating losses to offset our future taxable income, if any, until such net operating losses are used or expire. These net operating loss carryforwards could expire unused before offsetting potential future income tax liabilities.

Additionally, an ownership change, as defined by Section 382 of the Code, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50% over a three-year period. If the Company has experienced a change of control, as defined by Section 382 of the Code, at any time since inception, utilization of the Company’s net operating loss carryforwards would be subject to an annual limitation. Any limitation may result in expiration of a portion of the net operating loss carryforwards before utilization. The Company has not conducted a study to assess whether a change of control, as defined by Section 382 of the Code, has occurred and it is possible that we have experienced an ownership change limitation. We may experience ownership changes in the future as a result of subsequent shifts in our stock ownership, some of which may be outside of our control. If an ownership change occurs and our ability to use our net operating loss carryforwards is materially limited, it would harm our future operating results by effectively increasing our future tax obligations.

Risks Relating to Our Securities

The price of our common stock has been and may continue to be volatile.

Our stock price has historically fluctuated widely and is likely to continue to be volatile. Because we are at an early stage of development and in the absence of product revenue as a measure of operating performance, we anticipate that the market price for our common stock may be influenced by, but not limited to, such factors as:

The stock markets, in general, and the markets for drug delivery and pharmaceutical company stocks, in particular, have experienced extreme volatility, particularly in response to the coronavirus outbreak, that has often been unrelated to the operating performance of particular companies. These broad market fluctuations may adversely affect the trading price of our common stock. In addition, the limited trading volume of our stock may contribute to its volatility.

InWe may incur significant costs from class action litigation due to our historical or expected stock volatility.

Our stock price has historically fluctuated significantly and may continue to do so in the future. This risk is relevant to us as in the past, following periods of volatility in the market price of a particular company’s securities, litigation has often been brought against that company.company that issued the stock. If litigation of this type is brought against us by any of our stockholders, even if the lawsuit is without merit, it could be extremely expensive and divert management’s attention and the Company’s resources.

We have issuedOur Board of Directors has the authority to issue shares of “blank check” preferred stock in the past and possibly may issue more preferred stock in the future, and the terms of the preferred stock may reduce the value of our common stock.

We are authorized to issue up to 10,000,000 shares of preferred stock in one or more series. Our Board of Directors may determine the terms of future preferred stock offerings without further action by our stockholders. The issuance of our preferred stock could affect the rights of existing stockholders or reduce the value of our outstanding preferred stock or common stock. In particular, rights granted to holders of certain series of preferred stock may include voting rights, preferences as to dividends and liquidation, conversion and redemption rights and restrictions on our ability to merge with or sell our assets to a third party.

We may acquire other businesses or form joint ventures that may be unsuccessful and could dilute your ownership interest in the Company.

As part of our business strategy, we may pursue future acquisitions of other complementary businesses and technology licensing arrangements. We also may pursue strategic alliances. We have limited experience with respect to acquiring other companies and with respect to the formation of collaborations, strategic alliances and joint ventures. We may not be able to integrate such acquisitions successfully into our existing business, and we could assume unknown or contingent liabilities. We also could experience adverse effects on our reported results of operations from acquisition related charges, amortization of acquired technology and other intangibles and impairment charges relating to write-offs of goodwill and other intangible assets from time to time following the acquisition. Integration of an acquired company requires management resources that otherwise would be available for ongoing development of our existing business. We may not realize the anticipated benefits of any acquisition, technology license or strategic alliance. There is no assurance that we will be successful in developing such assets, and a failure to successfully develop such assets could diminish our prospects.

To finance future acquisitions, we may choose to issue shares of our common stock or preferred stock as consideration, which would dilute current stockholders’ ownership interest in us. Alternatively, it may be necessary for us to raise additional funds through public or private financings. Additional funds may not be available on terms that are favorable to us and, in the case of equity financings, may result in dilution to our stockholders. Any future acquisitions by us also could result in large and immediate write-offs, the incurrence of contingent liabilities or amortization of expenses related to acquired intangible assets, any of which could harm our operating results.

We do not anticipate paying cash dividends in the foreseeable future.

Our business requires significant funding. We currently plan to invest all available funds and future earnings in the development and growth of our business and do not anticipate paying any cash dividends on our common stock in the foreseeable future. As a result, capital appreciation, if any, of our common stock will be the sole source of potential gain for our stockholders for the foreseeable future.

Provisions of our certificate of incorporation and bylaws and Delaware law might discourage, delay or prevent a change of control of the Company or changes in our management and, as a result, depress the trading price of our common stock.

Our certificate of incorporation and bylaws contain provisions that could discourage, delay or prevent a change of control of the Company or changes in our management that the stockholders of the Company may deem advantageous. These provisions:

Although we believe these provisions collectively provide for an opportunity to receive higher bids by requiring potential acquirers to negotiate with our Board of Directors, they would apply even if the offer may be considered beneficial by some stockholders. In addition, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management team by making it more difficult for stockholders to replace members of our Board of Directors, which is responsible for appointing the members of our management.

Moreover, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, which prohibits a person who owns in excess of 15% of our outstanding voting stock from merging or combining with us for a period of three years after the date of the transaction in which the person acquired in excess of 15% of our outstanding voting stock, unless the merger or combination is approved in a prescribed manner.

None.

On December 17, 2013, and subsequent amendment on January 22, 2019, we entered into a lease (the “Lease”) with 257 Simarano Drive, LLC, Brighton Properties, LLC, Robert Stubblebine 1, LLC and Robert Stubblebine 2, LLC to lease office and laboratory space in the building known as the “Main Building” located at 257 Simarano Drive, Marlborough, Massachusetts, covering approximately 7,581 square feet. The premises are used by the Company for office and laboratory space. The term of the Lease commenced on April 1, 2014 and expires on March 31, 2024, for a total of a ten year lease term. The base rent for the premises is $124,865 per annum, payable on a monthly basis. Each year thereafter, the base rent shall increase by approximately 3% over the base rent from the prior year. With six months’ advance notice, either party may terminate the lease on March 31, 2021, paying the non-terminating party six months’ rent as a penalty or on March 31, 2022, paying the non-terminating party three months’ rent as a penalty.

We believe that our facilities are suitable for our current needs.

From time to time, we may become a party to various legal proceedings and complaints arising in the ordinary course of business. There are none deemed to be material at this time.

Not applicable.

PART II.

Market Information

Our common stock is listed on The Nasdaq Capital Market under the symbol “PHIO.”

Holders

At March 20, 2020,18, 2021, there were approximately 1819 holders of record of our common stock. Because many of our shares are held by brokers and other institutions on behalf of stockholders, we are unable to estimate the total number of individual stockholders represented by these holders of record.

Dividends

We have never paid any cash dividends and do not anticipate paying any cash dividends on our common stock in the foreseeable future. We expect to retain future earnings, if any, for use in our development activities and the operation of our business. The payment of any future dividends will be subject to the discretion of our Boardboard of Directorsdirectors and will depend upon, among other things, our results of operations, financial condition, cash requirements, prospects and other factors that our Boardboard of Directorsdirectors may deem relevant.

Securities Authorized for Issuance Under Equity Compensation Plans

See Item 12 to this Annual Report on Form 10-K for additional information about the securities authorized for issuance under our equity compensation plans.

Recent Sales of Unregistered Sales of Securities

No sales or issues of unregistered securities occurred that have not previously been disclosed in a Quarterly Report on Form 10-Q or in a Current Report on Form 8-K.

Purchases of Equity Securities by the Issuer and Affiliated Purchases

We did not repurchase any shares of our common stock during the years ended December 31, 20192020 or 2018.2019.

As a smaller reporting company, we are not required to provide this information.

The following discussion of our financial condition and results of operations should be read in conjunction with our consolidated financial statements and the notes to those consolidated financial statements included in Item 8 of this Annual Report on Form 10-K. This discussion contains forward-looking statements that involve significant risks and uncertainties. As a result of many factors, such as those set forth under “Risk Factors” and elsewhere in this Annual Report on Form 10-K, our actual results may differ materially from those anticipated in these forward-looking statements. Please refer to the discussion under the heading “Forward-Looking Statements” above.

Overview

Phio Pharmaceuticals Corp. is a biotechnology company developing the next generation of immuno-oncology therapeutics based on our self-delivering RNAi (“INTASYL™”) therapeutic platform. The Company'sOur efforts are focused on silencing tumor-induced suppression of the immune system through our proprietary INTASYL™INTASYL platform with utility in immune cells and/orand the tumor micro-environment. Our goal is to develop powerful INTASYL™INTASYL therapeutic compounds that can weaponize immune effector cells to overcome tumor immune escape, thereby potentially providing patients a powerful new treatment option that goes beyond current treatment modalities.

Our development efforts are based on our broadly patented INTASYL™INTASYL technology platform. Our INTASYL™INTASYL compounds do not require a delivery vehicle to penetrate into tissues and cells and are designed to “silence” or down-regulate, the expression of a specific gene which is over-expressed in cancer. We believe that our INTASYL™INTASYL platform uniquely positions the Company in the field of immuno-oncology because of this andfor the following reasons:

The self-delivering nature of our compounds makes INTASYL™ INTASYL ideally suited for use with adoptive cell transfertherapy (“ACT”) treatments andas well as for direct therapeutic use. ACT consists of the infusion of immune cells with antitumor properties.properties, after growing them in a lab to large numbers. These cells can be derived from unmodified (i.e. naturally occurring) immune cells, immune cells isolated from resected tumors, or genetically engineered immune cells recognizingthat recognize tumor neoantigen/neoepitope cells.

Currently, ACT therapies for Regardless of the treatmentsource of immune cells (ACT or naturally occurring immune cells), in patients with solid tumors, facethese cells have several hurdles.shortcomings that inhibit their full therapeutic potential. By using INTASYL technology during the manufacturing of such ACT cell products we can improve the phenotype and function of these cells, potentially leading to better therapeutic outcomes. Multiple inhibitory mechanisms restrain immune cells used in ACT from effectively eradicating tumors, including immune checkpoints, reduced cell fitness and cell persistence. Furthermore, the immunosuppressive tumor micro-environment (the “TME”) can pose a formidable barrier to immune cell infiltration and function. By using INTASYL based drugs administered directly, we can reprogram cells in the TME to help overcome these immunosuppressive mechanisms.

Phio hasWe have developed a product platform based on our INTASYL™ INTASYL technology that allows easy, precise, rapid, and selective non-genetically modified programming of ACT cells (ex vivo, during manufacturing) and of the TME (in vivo, by local application), resulting in reduced immune inhibition and in improved immunotherapy.

INTASYL Use To Improve Adoptive Cell TransferTherapy Products

ACT includesis a numberform of different typesimmune therapy based on the use of immunotherapy treatments. These treatments use immune cells, thatisolated from patients, donors or retrieved from allogeneic immune cell banks. They are grown in a lab to large numbers, followed by administering them to the bodypatient to fight the cancer cells.cancer. Sometimes, immune cells that naturally recognize a tumor are used, while other times immune cells are modified or “engineered”“genetically engineered” to make them recognize and kill the cancer cells. There are several types of ACT, including: a.) non-engineered cell therapy in which immune cells are grown from the patient’s tumor or blood, such as tumor infiltrating lymphocytes (“TILs”), or from donor blood or tissue such as natural killer (“NK”) cells, dendritic cells (“DC”) and macrophages, and b.) genetically engineered immune cells that are genetically modified to recognize specific tumor proteins and to remain in an activated state (such as T cell receptor technology (“TCRs”), chimeric antigen receptor (“CAR”) T cells, or CAR-NK cells).

In ACT,Multiple inhibitory mechanisms restrain immune cells are isolatedused in ACT from patients, donors or retrieved from allogeneiceffectively eradicating tumors, including immune checkpoints, reduced cell fitness and cell persistence, and other barriers to immune cell banks. The immune cells are then expandedinfiltration and modified before being returned and used to treat the patient.function mainly in solid tumors. We believe our INTASYL™INTASYL compounds are ideally suited to be used in combination with ACT products. With INTASYL compounds, we can unlock the full potential of ACT, by improving the immune cell function, differentiation and metabolism, in order to make these immune cells more effective.effective without the need for additional complicated manufacturing steps and/or genetic engineering.

Our approach to immunotherapy builds on well-established methodologies of ACT and involves the treatment of immune cells with our INTASYL™ INTASYL compoundsex vivo while they are grown in the lab and before administering them to the patient. Because our INTASYL™ INTASYL compounds do not require a delivery vehicle to penetrate into the cells, we are able to enhance the function of these cells (for example, by inhibiting the expression of immune checkpoint genes) by merely adding our INTASYL™ INTASYL compounds during the expansion process and without the need for genetic engineering. After enhancing these cells ex vivoengineering, they are returnedwithout the need for complex delivery vehicles or formulations, and without additional needed complex manufacturing steps. By adding INTASYL to the patient for treatment.

Our method introduces an important step incell culture media used during theex vivo processing of immune cells. This step uses our INTASYL™ technology to cell expansion, we can reduce or eliminate the expression of genes that make the immune cells less effective. For example, with our INTASYL™INTASYL compounds, we can reduce the expression of immunosuppressive receptors or proteins by the therapeutic immune cells, potentially enabling them to overcome tumor resistance mechanisms and thus improving their ability to destroy the tumor cells.In various types of immune cells tested to date, INTASYL™INTASYL treatment results in potent silencing while maintainingwith close to 100% transfection efficiency and while maintaining nearly full cell viability. After expanding these cells and enhancing them with INTASYL ex vivo, they are returned to the patient for treatment.

One of the main issues with ACT is that the cells are very susceptible to the cancer signals that turn down the immune responseOur lead product candidate and continuous activation of these cells causes them to become exhausted. These factors, among others, may reduce their efficacy and lifespan. A technology that can reprogram the immune cells used in ACT, such as with INTASYL™ technology, is of key interest now in the current immuno-oncology world. In comparison to other technologies available, reprogramming cells with INTASYL™ does not require genetic engineering, its use is not limited to specific cell types and can be easily integrated with cell manufacturing approaches.

We currently have two product candidates that are being developed for use in ACT, PH-762 and PH-804. PH-762, our most advanced program and lead pipelinebeing developed in ACT is PH-762, an INTASYL compound that targets the checkpoint protein PD-1, a checkpoint protein on immune cells.PD-1. Checkpoint proteins, such as PD-1, normally actsact as a type of “off switch” that helps keep theprevent T cells from attacking othercertain cells, such as cancer cells, in the body. Our T cells are immune cells that protect the body from cancer cells and are importantinfections.

Data developed by Phio and with collaborators has shown that PH-762 silences PD-1 checkpoint expression, thereby removing the “off switch” and resulting in enhanced T cell activation and tumor cytotoxicity. Experimental data shows that PH-762 can silence the expression of PD-1 in target human T cells in a potent and durable manner, and can increase the function of patient derived TILs for use in ACT, showing that PH-762 is applicable for use in both ACT and as a standalone direct therapeutic.

In March 2021, the Company announced that it entered into a clinical development collaboration with AgonOx, Inc. (“AgonOx”), a private company developing a pipeline of novel immunotherapy drugs targeting key regulators of the immune response to cancer. Under the agreement, the companies will collaborate on the development of novel T cell-based therapies using PH-762 and AgonOx’s “double positive” (DP) TIL technology. AgonOx has demonstrated that their DP CD8+ T cells isolated from human solid tumors (DP TILs) have increased tumor killing activity when compared to TILs that were not enriched prior to expansion. Preclinical data from AgonOx in collaboration with Phio has shown that treating DP TIL with PH-762 increases the tumor killing activity of the DP TILs even further (a two-fold increase). As a result, the use of PH-762 treated DP TILs is expected to enhance therapeutic responses in cancer data. Based on these data showing that the combination of our technologies can result in TIL therapeutics, our collaboration will focus on conducting a clinical study for PH-762 treated DP TILs. Under the terms of the collaboration agreement, AgonOx will receive financial support for the activationclinical trial from Phio and Phio will be entitled to certain future development milestones and sales-related royalty payments from AgonOx’s DP TIL technology. The clinical trial in ACT with PH-762 and AgonOx’s DP TIL technology is expected to start in the third quarter of immune cells to fight infection. 2021.

Our second pipelineproduct candidate in ACT is PH-894, an INTASYL compound that targets BRD4 which is a regulator of gene expression impacting cell differentiation. In previous studies, PH-894 has been shown to improve T cell function and persistence by differentiating T cells into a more active state (stem-cell like memory phenotype). Data, completed in partnership with the Karolinska Institutet in Sweden, demonstrated that the application of PH-894, was shown to silence BRD4 in human T cells during expansion for ACT, which has the potential to confer superior anti-tumor activity, for example by improving T cell persistence. With this data, we expanded our collaboration with the Karolinska Institutet to build upon these findings and develop INTASYL compounds for additional targets and cell types toward clinical application in areas of the Karolinska Institutet’s ongoing clinical research.

We are also developing our INTASYL compound PH-804 for use in ACT. PH-804 targets the suppressive immune receptor TIGIT, which is a checkpoint protein present on T cells and NK cells.

Data developed in-house and with our collaborators, which include both leading academic centers and corporate institutions, to date has shown that PH-762 can elicit PD-1 checkpoint blockade by silencing PD-1 receptor expression resulting in enhanced T cell activation and tumor cytotoxicity. We have also shown with studies completed with our collaborators that PH-804 can silence the expression of TIGIT in NK cells and T cells, overcoming their exhaustion“off switch” and therebythe cells becoming “weaponized.”“weaponized” to kill cancer cells.

Recent data shown by the Company as well as with our collaborators, Iovance Biotherapeutics, Inc. and the Karolinska Institutet, at the 2019 Society for Immunotherapy of Cancer annual meeting further supports the application of INTASYL™ technology in immunotherapy of cancer. PH-762, our most advanced program, has shown to silence the expression of checkpoint molecule PD-1 in target human T cells in a potent and durable manner suitable for both ACT and intra-tumoral injection, and increases function of patient derived TILs for ACT. The application of INTASYL™ compounds to novel immuno-oncology targets was shown by the silencing of BRD4, a regulator of gene expression impacting cell differentiation and function, by a BRD4 targeting INTASYL™ compound in human T cells during expansion for ACT, which has the potential to confer superior anti-tumor activity.

Direct Therapeutic Use of INTASYL Towards the Tumor Micro-Environment

The TME is the environment that surrounds and feeds a tumor, including normal cells, blood vessels, immune cells, and the extracellular matrix. A tumor can change the microenvironment and the microenvironment can affect how a tumor grows and spreads and can createThe TME is an immunosuppressive microenvironmentenvironment that inhibits the immune system’s natural ability to recognize and destroy tumor cells. This attractscells by negatively impacting how immunosuppressive cells inducesare being attracted and activates immune checkpoint expression and excludes and exhausts T cells.activated. Reprogramming different components of the TME may overcome its resistance to immunotherapy.

Such reprogramming of the TME by INTASYL™INTASYL compounds through direct local administration into the tumor, could potentially become an important form of (neo)adjuvant therapy. We believe that this will also show that our contributions with our INTASYL™ compounds in immuno-oncology are not limited to use with a cell therapy platform. Additionally, theThe Company has previously shown in a clinical setting that its INTASYL™ our INTASYL compounds are safe and well-tolerated following local administration.administration, therefore we believe that our INTASYL technology can not only be used with ACT, but can also be used as an independent therapeutic platform.

Our INTASYL™We are developing our PH-762, PH-894 and PH-804 INTASYL compounds being developedalso for use in ACT, are also being developed for use directly towardsas direct therapeutics to reprogram the TME including PH-762in situ transfection and PH-804. We are also working on other relevant compounds for TME targets, such as PH-790, an INTASYL™ compound targeting PD-L1. PD-L1 is a protein that keepsactivation of immune cells from attacking nonharmful cells in the body. If cancer cells have large amounts of PD-L1, this “tricks” the immune system into not recognizing and attacking the tumor. Our approach with PH-790 is to block the PD-L1 protein, which may prevent cancer cells from inactivating T cells and attack the cancer.TME.

Our collaborative research agreement with Gustave Roussy, a leading comprehensive cancer center in France, concentrates on determiningAnimal studies conducted by the feasibilityCompany showed that local administration of our INTASYL™ platform to targetPH-894 or the TME via intra-tumoral injection. An in-vivo study completed with Gustave Roussy demonstrated that an INTASYL™ compound delivered viamouse version of PH-762 through intra-tumoral injection resulted in potent anti-tumoral effects. The treated animals showed silencinga complete and statistically significant inhibition of gene expression with our INTASYL™ compounds with greater than 90% reduction of the target gene expression in a mouse model of melanoma.

Recenttumor growth, whereas placebo treated animals displayed exponential tumor growth. inIn vivo studies performed by the Company showedwith PH-804showed that intra-tumoral injectionsinjection of a mouse version of PH-804 reduced the tumor growth in colorectal carcinoma tumor bearing mice, which was shown to beinhibit tumor growth and was correlated with the silencing of TIGIT mRNA expression and anin increase in cytotoxic effector T cells in the TME.

The combined PH-804, PH-762, and PH-894 data further shows that INTASYL compounds can trigger associated changes in the TME such as an increase of TILs, including CD8+ T cells responsible for tumor cell killing, and an increase of activation markers on these cells. These preclinical findings demonstrate that direct injection of INTASYL compounds can successfully infiltrate solid tumors and impact the TME by activating the immune response in animal models of solid tumors resulting in reduced tumor growth. A key challenge for many other immunotherapy platforms is to be able to achieve an adequate therapeutic effect in solid tumors with an acceptable safety profile. Many of the available systemic immuno-therapeutics indeed come with dose limiting immune-related adverse events, which we believe can be mitigated with local INTASYL treatment.

Based on our positive preclinical data, the Company is preparing for a clinical study with PH-762 using intra-tumoral administration for patients with advanced melanoma. The required preclinical studies and steps needed to initiate the clinical trial with PH-762 as a direct therapeutic are continuing and ongoing. The clinical trial will be conducted at the Gustave Roussy Institute, which is France’s largest cancer center and Dr. Caroline Robert will be our lead principal investigator. The Company expects to start the clinical trial evaluating the use of PH-762 as a direct therapeutic in the fourth quarter of 2021.

We are also investigating other relevant compounds for TME targets, such as PH-790, an INTASYL compound targeting PD-L1. PD-L1 is a protein formed by cancer cells that activate the PD-1 “off switch” on immune cells. Our approach with PH-790 is to block the formation of the PD-L1 protein, which may prevent cancer cells from inactivating T cells and attack the cancer. Recent data presented demonstrated that the antitumoral efficacy of our individual pipeline products, PH-762, PH-790 and PH-804, can be further improved by combining them in a single drug treatment. We have shown that, in contrast to other technology platforms, we can efficiently target multiple proteins, in a single drug treatment without negative consequences related to the potency of the individual components. Animal data showed that the combination of our INTASYL compounds in a single formulation (at suboptimal doses of the individual agents) inhibited tumor growth without having a negative impact on the tolerability of the treatment.

Impact of COVID-19 on our Business

In December 2019, a novel strain of coronavirus that causes COVID-19 was reported to have surfaced in Wuhan, China and has since spread to other parts of the world, including the United States. In March 2020, the World Health Organization (the “WHO”) declared the outbreak a pandemic.

Health and Safety

From the first signs of the outbreak, we have taken proactive measures intended to protect the health and safety of our employees. We have implemented safety measures following the guidance provided by the WHO, the Centers for Disease Control (the “CDC”) and governmental authorities, which include formal policies related to working remotely for employee personnel who do not need to be physically present in our offices, the wearing of face masks while in the office, physically distancing workspaces, cleaning protocols, staggered scheduling and social distancing protocols, and suspending travel. The Company has also implemented protocols to address actual and suspected cases of COVID-19 and encourages sick employees to remain home. We expect to continue following these safety measures and may take further actions as we require, as government authorities require or recommend, or as we determine to be in the best interests of our employees.

Operations

Our operations have continued to operate with limited impact and are operating in accordance with federal and state government, WHO and CDC guidelines. We have implemented enhanced safety measures, as discussed above, and have experienced limited absenteeism from our employees due to the coronavirus pandemic and we do not currently expect that our operations will be significantly impacted by employee absenteeism. While the measures to contain and prevent the spread of coronavirus may be modified or extended, we expect that our activities, including our internal research and development functions, will continue to remain largely operational. We believe the impact to our operations has been minimal thus far, however current and future restrictions may further impact our operations and may slow or diminish our research and development activities.

Supply and Services

As a result of the coronavirus pandemic, certain of our third-party suppliers and service providers on which we rely have seen impacts to their operations. If the impact to their operations continue or extend, it may in turn affect our operations. We previously had been able to engage with third-party service providers in areas with limited or no impact (e.g. countries with limited or no restrictions), but with the global spread of the virus and associated restrictions, this has been no longer possible. The Company does not expect a material impact to its program’s anticipated timelines as a result of potential delays from our third-party service providers and believes that we have a sufficient supply of our INTASYL compounds to conduct our ongoing preclinical studies and initial clinical activities. The Company has also undertaken efforts to mitigate potential future impact by identifying and engaging alternative third-party service providers and suppliers. However, the ultimate impact to the third parties on which we rely is highly uncertain and subject to change. If the measures to contain the outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in turn slow or delay our preclinical and clinical activities, and/or result in higher costs.

With the global spread of the coronavirus and the associated safety measures to contain the spread by governmental authorities, a delay in the commencement of new clinical trials and in the enrollment and participation of patients in clinical trials may occur. The steps required for us to initiate our clinical trials with PH-762 in the second half of 2021 are continuing and ongoing, however, the Company does not yet know the full extent of potential delays or impacts related to its planned clinical activities.

Liquidity and Capital Resources

While we believe that the coronavirus pandemic has not had a significant impact on our financial condition at this time, the extent to which the coronavirus pandemic impacts our results will depend on future developments, which are highly uncertain and cannot be predicted, including new information which may emerge concerning the severity of the coronavirus pandemic and the actions to contain the coronavirus or treat its impact, among others.

Due to our uncertainty around our ability to access the capital markets to provide the necessary working capital to fund our long-term operations as a result of the coronavirus pandemic, the Company applied for and received a loan of $231,252 in May 2020 under the Paycheck Protection Program (the “PPP”) as part of the Coronavirus Aid, Relief and Economic Security (the “CARES Act”). The Company carefully assessed the requirements at the time of applying for the PPP loan and believed it was necessary to support our operations. The PPP loan matures in May 2022, bears an interest rate of 1% per year and monthly principal and interest payments are deferred to that date that the amount of loan forgiveness is remitted to the lender. The Company believes it has used the loan proceeds for the eligible purposes allowed and applied for full loan forgiveness. On February 18, 2021, the Small Business Administration determined that the Company’s application for full loan forgiveness was fully approved and the full amount of the PPP loan was remitted to the lender for forgiveness. In connection with and addition to the PPP, the Company took other proactive steps to control costs in response to the coronavirus pandemic, which included the reduction of senior management salaries by 10% from May to December 2020. We believe these savings helped to mitigate the financial impact of the coronavirus pandemic on our financial condition.

Overall, we do not yet know the full extent of potential delays or the impact on our business, financial condition, or our preclinical and clinical trial activities and there may be developments outside of our control that require us to adjust our operating plans and, therefore, given the nature of the situation, cannot reasonably estimate the impact of the coronavirus on our financial condition, results of operations or cash flows in the future.

Corporate Information

On January 10, 2020, the Board of Directors of the Company approved a 1-for-55 reverse stock split of the Company’s outstanding common stock, which was effected on January 15, 2020. All share and per share amounts have been retroactively adjusted for all periods presented to give effect to the reverse stock split.

Critical Accounting Policies and Estimates

The discussion and analysis of our financial condition and results of operations is based upon our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States.States (“GAAP”). The preparation of these consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an ongoing basis, we evaluate our estimates and base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions and could have a material impact on our reported results. While our significant accounting policies are more fully described in the notes to our consolidated financial statements included elsewhere in this Annual Report, we believe the following accounting policies to be the most critical in understanding the judgments and estimates we use in preparing our financial statements.

Research and Development Expenses

We are required to estimate our accrued research and development expenses, of which a significant portion related to third party providers theCompanyhas contractedwith to perform various preclinical and clinical activities onour behalf for the continued development ofour product candidates.This process includes reviewing open contracts and purchase orders, estimating the service performed and the associated cost incurredfor research and development services not yet billed or otherwise notified of actual cost. Examples of estimated accrued expenses related to research and development expenses include fees connected with clinical trial sites, third-party clinical research organizations and other preclinical and clinical-related activities and include such items as subject-related fees, laboratory work, investigator fees and analysis costs.

Research and development expenses are charged to expense as incurred. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses and expensed when the service has been performed or when the goods have been received. Accrued liabilities are recorded relatedwith respect to those expensesservices provided and/or materials received for which vendors have not yet billed the Company with respect to services provided and/or materials that it has received.Company. The financial terms of these contracts are subject to negotiation, vary from provider to provider and may result in uneven payment flows. There may be instances in which payments made to our vendors exceed the level of services provided and result in a prepayment of the expense. In other instances, payment depends on factors such as the successful completion of the enrollment of subjects or milestones.

AccrualsWe are required to estimate our accrued research and development expenses, of which a significant portion relate to third party providers the Company has contracted with to perform various research activities on our behalf for the continued development of our product candidates. This process includes reviewing open contracts and purchase orders, estimating the service performed and the associated cost incurred for research and development services not yet billed or otherwise notified of actual cost. Accrued liabilities for the services provided by contract research organizations are recorded during the period incurred based on such estimates and assumptions as expected cost, passage of time over which services will be performed, the level of effort to be expended in each period, the achievement of milestones and adjustment accordingly.other information available to us. Estimates of our research and development accruals are assessed on a quarterly basis based on the facts and circumstances known to us at that time and other information available to us. We recognize costs for certain development activities based on an evaluation of the progress to completion of specific tasks using information and data provided to us by our vendors. We periodically confirm the accuracy of the estimates with our third party contractorsvendors and make adjustments, if necessary. facts and circumstances known to us at that time, and adjusted accordingly.

Actual results may differ from these estimates and could have a material impact on ourthe Company’s reported results. OurThe Company’s historical accrual estimates have not been materially different from ourits actual costs. Due to the nature of estimates, we cannot provide assurance that we will not make changes to our estimates in the future as we become aware of additional information about the conduct of our preclinical or clinicalresearch activities.

Stock-based Compensation

The Company follows the provisions of the Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“ASC”) Topic 718, “Compensation – Stock Compensation” (“ASC 718”), which requires the measurement and recognition of compensation expense for all stock-based payment awards. Stock compensation expense based on the grant date fair value estimated in accordance with the provisions of ASC 718 is recognized as an expense over the requisite service period.

We determine the fair value of restricted stock and restricted stock units based on the fair value of our common stock on the date of grant. We estimate the fair value of our stock optionoptions using the Black-Scholes option pricing model, which requires us to develop subjective estimates to be used in calculating the grant date fair value of stock options. The use of the model requires us to make estimates of highly subjective assumptions, such as expected stock price volatility and the estimated expected term of each award. Stock-based compensation expense based on the grant date fair value estimated in accordance with the provisions of ASC 718 is recognized as an expense over the requisite service period.

Derivative Financial Instruments

During the normal course of business we may issue warrants to vendors as consideration to perform services. We may also issue warrants as part of a debt or equity financing. Warrants and other derivative financial instruments are accounted for either as equity or as an asset or liability, depending on the characteristics of each derivative financial instrument. Warrants classified as equity are measured at fair value and recorded as additional paid in capital in stockholders’ equity at the date of issuance. No further adjustments to their valuation are made. Derivative financial instruments classified as an asset or liability are measured at fair value on the issuance date and are revalued on each subsequent balance sheet date. The changes in the fair value are recognized as current period income or loss.

Leases

In connection with our adoption on January 1, 2019, the Company follows the provisions of the FASB ASC 842, “Leases” (“ASC 842”). At the inception of a contract, the Company determines whether the contract is or contains a lease based on all relevant facts and circumstances. For contracts that contain a lease, the Company identifies the lease and non-lease components, determines the consideration in the contract and recognizes the classification of the lease as operating or financing. At the commencement date of the lease,For leases with a term greater than one year, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term. The Company has elected not to recognize leases with a term less than one year onat the balance sheet.commencement date of the lease.

Lease liabilities and the corresponding right of use assets are recorded based on the present value of lease payments to be made over the lease term. The discount rate used to calculate the present value is the rate implicit in the lease, or if not readily determinable, the Company’s incremental borrowing rate. The Company’s incremental borrowing rate is the rate of interest that wethe Company would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Certain adjustments to the right of use asset may be required for items such as initial direct costs or incentives received. Lease payments on operating leases are recognized on a straight-line basis over the expected term of the lease. Lease payments on financing leases are recognized using the effective interest method.

Financial Operations Overview

Revenues

To date, we have primarily generated revenues through government grants. We have not generated any commercial product revenue.

In the future, we may generate revenue from a combination of government grants, research and development agreements, license fees and other upfront payments, milestone payments, product sales and royalties in connection with future strategic collaborators and partners. We expect that any revenue we generate will fluctuate from period to period as a result of the timing of the achievement of any preclinical, clinical or commercial milestones and the timing and amount of payments received relating to those milestones and the extent to which any of our product candidates are approved and successfully commercialized by us or strategic collaborators and partners. If the Company or any future partner fails to develop product candidates in a timely manner or obtain regulatory approval for them, then our ability to generate future revenue and our results of operations and financial position would be adversely affected.

Research and Development Expenses

Research and development expenses relate to compensation and benefits for research and development personnel, facility-related expenses, supplies, external services, costs to acquire technology licenses, research activities under our research collaborations, expenses associated with preclinical and clinical development activities and other operating costs. Research and development expenses are charged to expense as incurred. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses and expensed when the service has been performed or when the goods have been received.Accrued liabilities are recorded related to those expenses for which vendors have not yet billed the Company with respect to services provided and/or materials that it has received.

Our research and development programs are focused on the development of the next generation of immuno-oncology therapeutics based on INTASYL™our INTASYL therapeutic platform. Since we commenced operations, research and development has composed a significant portion of our total operating expenses and is expected to compose the majority of our spending for the foreseeable future.

There are risks in any new field of drug discovery that preclude certainty regarding the successful development of a product. We cannot reasonably estimate or know the nature, timing and costs of the efforts necessary to complete the development of, or the period in which material net cash inflows are expected to commence from, any product candidate. Our inability to make these estimates results from the uncertainty of numerous factors, including but not limited to:

Failure to complete any stage of the development of our product candidates in a timely manner could have a material adverse effect on our results of operations, financial position and liquidity.

General and Administrative Expenses

General and administrative expenses relate to compensation and benefits for general and administrative personnel, facility-related expenses, professional fees for legal, audit, tax and consulting services, as well as other general corporate expenses.

Other Income, net

Other income consists primarily of interest income and expense and various income or expense items of a non-recurring nature.

Results of Operations

The following data summarizes our results of operations for the periods indicated, in thousands:

Comparison of the Years Ended December 31, 20192020 and 2018

Revenues

The following table summarizes our total revenues, for the periods indicated, in thousands:

In August 2017, the Company entered into a purchase agreement (the “2017 Purchase Agreement”) with Lincoln Park Capital, LLC (“LPC”), pursuant to which the Company had the right to sell to LPC up to $15,000,000 in shares of the Company’s common stock. The 2017 Purchase Agreement expired on acceptable terms, or at all.Moreover,April 1, 2020 and a total of $1,602,000 in shares of common stock were sold to LPC under the global coronavirus pandemicagreement. In August 2019, the Company entered into a purchase agreement (the “2019 Purchase Agreement”) with LPC, pursuant to which the Company has ledthe right to significant uncertaintysell to LPC up to $10,000,000 in shares of the Company’s common stock, subject to certain limitations and increased volatilityconditions set forth in the capital markets. If these conditionsagreement. The Company is initially limited to the issuance of 19.99% of the Company’s shares outstanding on the date of the 2019 Purchase Agreement to LPC unless stockholder approval is obtained to issue more than such amount or the average price of all sales under the 2019 Purchase Agreement exceed certain amounts as set forth in the capital markets continue foragreement. To date, no shares of common stock have been sold to LPC under the 2019 Purchase Agreement.

On January 25, 2021, the Company sold 4,420,863 shares of Company common stock at a purchase price per share of $3.07, pre-funded warrants to purchase an extended periodaggregate of time it may impact our ability140,065 shares of Company common stock at a purchase price per pre-funded warrant share of $3.069, and warrants to raise capital. If we failpurchase an aggregate of 3,420,696 shares of the Company’s common stock with an exercise price of $3.00 per warrant share in a private placement transaction. Net proceeds to obtain additional funding when needed, we would be forced to scale back or terminate our operations or to seek to merge with orthe Company are estimated to be acquired by another company.$12,700,000 after deducting placement agent fees and offering expenses.

On February 12, 2021, the Company sold 2,246,784 shares of Company common stock at a purchase price of $3.42 per share in a registered direct offering under the Company’s Form S-3 “shelf” registration statement. Net proceeds to the Company are estimated to be $6,900,000 after deducting placement agent fees and offering expenses.

We believe that our existing cash at December 31, 2020 and the net proceeds received from the Company’s Februaryfinancing activities subsequent to December 31, 2020, Registered Offering and February 2020 Underwritten Offering,as discussed above, should be sufficient to fund operations for at least the next 12 months fromfrom the date this Annual Report on Form 10-K is filedof the release of the associated financial statements.

Cash Flow

The following table summarizes our cash flows for the periods indicated, in thousands:

Net Cash Flow from Operating Activities

Net cash used in operating activities was $8,802,000 for the year ended December 31, 2020, as compared with $8,645,000 for the year ended December 31, 2019, compared with $7,520,000 for the year ended December 31, 2018.2019. The increase of $1,125,000in cash used in operating activities was primarily attributabledue to an increase in net lossthe changes in operating assets and liabilities as result ofcompared to the increasesame period in the Company’s operating expenses as compared with the prior year, as discussed above, partially offset by a reduction in cash used for working capital.year.

Net Cash Flow from Investing Activities

Net cash used in investing activities was $19,000 for the year ended December 31, 2020, as compared with $72,000 for the year ended December 31, 2019, compared with $5,000 for the year ended December 31, 2018.2019. The increasedecrease in net cash flows from investing activities was primarily related to the purchaseamount of officelaboratory and labcomputer equipment as compared with the priorpurchases year period.over year.

Net Cash Flow from Financing Activities

Net cash provided by financing activities was $16,131,000 for the year ended December 31, 2020, as compared with $772,000 for the year ended December 31, 2019, compared with $18,823,000 for2019. The increase in net cash flows from financing activities was primarily due to net proceeds received by the Company from the issuance of securities and warrant exercises during year ended December 31, 2018. The decrease was primarily due2020 as compared to the timing and amount of capital raise activity completed bysame period in the Company during fiscal year 2019 as compared with fiscal year 2018.prior year.

Off-Balance Sheet Arrangements

In connection with certain license agreements, we are required to indemnify the licensor for certain damages arising in connection with the intellectual property rights licensed under the agreement. In addition, we are a party to a number of agreements entered into in the ordinary course of business that contain typical provisions that obligate us to indemnify the other parties to such agreements upon the occurrence of certain events. These indemnification obligations are considered off-balance sheet arrangements in accordance with ASC Topic 460, “Guarantor’s Accounting and Disclosure Requirements for Guarantees, Including Indirect Guarantees of Indebtedness of Others.” To date, we have not encountered material costs as a result of such obligations and have not accrued any liabilities related to such obligations in our financial statements. See Note 78 to our consolidated financial statements for further discussion of these indemnification agreements.

As a smaller reporting company, we are not required to provide this information.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm

Stockholders and Board of Directors

Phio Pharmaceuticals Corp.

Marlborough, Massachusetts

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Phio Pharmaceuticals Corp. (the “Company”) and subsidiary as of December 31, 20192020 and 2018,2019, the related consolidated statements of operations, stockholders’ equity, and cash flows for each of the two years in the period ended December 31, 2019,2020, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company and subsidiary at December 31, 20192020 and 2018,2019, and the results of theirits operations and theirits cash flows for each of the two years in the period ended December 31, 20192020, in conformity with accounting principles generally accepted in the United States of America.

Change in Accounting Principle

As discussed in Note 4 to the consolidated financial statements, on January 1, 2019, the Company changed its method of accounting for leases due to the adoption of Accounting Standards Update 2016-02,Leases (ASC 842).

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

Accounting for warrants issued as part of equity offerings

As described in Note 9 to the consolidated financial statements, the Company entered into two registered direct offerings and an underwritten public offering during 2020 that included the issuance of common stock and warrants to purchase common stock. The warrants were evaluated for proper classification on the balance sheet and it was determined that the warrants issued in these equity offerings should be classified within stockholders’ equity.

We identified the accounting for warrants issued as part of equity offerings as a critical audit matter. Our principal considerations included the existence of accounting complexities related to certain provisions of the warrant agreements, including provisions of cash settlement and derivative elements. Auditing these elements required especially challenging auditor judgement and significant audit effort as well as the need for specialized knowledge and skill assessing these elements of the agreement.

The primary procedures we performed to address this critical audit matter included:

/s/ BDO USA, LLP

We have served as the Company’s auditor since 2011.

Boston, Massachusetts

March 26, 202025, 2021

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED BALANCE SHEETS

(Amounts in thousands, except share data)

See accompanying notes to consolidated financial statements.

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED STATEMENTS OF OPERATIONS

(Amounts in thousands, except share and per share data)

See accompanying notes to consolidated financial statements.

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(Amounts in thousands, except share data)

See accompanying notes to consolidated financial statements.

PHIO PHARMACEUTICALS CORP.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Amounts in thousands)

See accompanying notes to consolidated financial statements.

PHIO PHARMACEUTICALS CORP.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Nature of Operations

Phio Pharmaceuticals Corp. (“Phio,” “we,” “our” or the “Company”) is a biotechnology company developing the next generation of immuno-oncology therapeutics based on its self-delivering RNAi (“INTASYL™”) therapeutic platform. The Company'sCompany’s efforts are focused on silencing tumor-induced suppression of the immune system through its proprietary INTASYL™ INTASYL platform with utility in immune cells and/orand the tumor micro-environment.The Company’s goal is to develop powerful INTASYL™INTASYL therapeutic compounds that can weaponize immune effector cells to overcome tumor immune escape, thereby potentially providing patients with a powerful new treatment option that goes beyond current treatment modalities.

In December 2019, a novel strain of coronavirus that causes COVID-19 was reported to have surfaced in Wuhan, China and has since spread to other parts of the world, including the United States. In March 2020, the World Health Organization (the “WHO”) declared the outbreak a pandemic. Our operations have continued with limited impact and are operating in accordance with federal, state, WHO and the Center for Disease Control’s guidelines, including the implementation of safety measures such as working remotely, staggered scheduling and cleaning protocols. While the measures to contain and prevent the spread of coronavirus may be modified or extended, we expect that our activities, including our internal research and development functions, will continue to remain largely operational.

As a result of the coronavirus pandemic, certain of our third-party suppliers and service providers on which we rely have seen impacts to their operations. If the impact to their operations continue or extend, it may in turn affect our operations. We previously had been able to engage with third-party service providers in areas with limited or no impact (e.g. countries with limited or no restrictions), but with the global spread of the virus and associated restrictions, this has been no longer possible. The Company does not expect a material impact to its program’s anticipated timelines as a result of potential delays from our third-party service providers and believes that it has a sufficient supply of our INTASYL compounds to conduct its ongoing preclinical studies and initial clinical activities. The Company has also undertaken efforts to mitigate potential future impact by identifying and engaging alternative third-party service providers and suppliers. However, the ultimate impact to these third parties on which we rely is highly uncertain and subject to change. If the measures to contain the outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in turn slow or delay our preclinical and clinical activities, and/or result in higher costs.

We believe that the coronavirus pandemic has not had a significant impact on our operations and financial condition thus far, however a variety of factors, including current and future restrictions and the length of the pandemic, may further impact our operations and may slow or diminish our research and development activities. The extent to which the coronavirus pandemic impacts our results will depend on future developments, which are highly uncertain and cannot be predicted.

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Additionally, certain reclassifications have been made to prior period financial statements to conform to the current period presentation.

Reverse Stock Split

Effective January 15, 2020, the Company completed a 1-for-55 reverse stock split of the Company’s outstanding common stock. All share and per share amounts in the financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in par value to additional paid-in capital. Unless otherwise noted, shares of common stock issued and outstanding, shares underlying warrants and stock awards, shares reserved, conversion price of convertible securities, exercise prices of warrants and stock awards and loss per share have been proportionately adjusted to reflect the reverse stock split. The reverse stock split did not reduce the number of authorized shares of the Company’s common stock or preferred stock.

Principles of Consolidation

The consolidated financial statements include the accounts of Phio and its wholly owned subsidiary, MirImmune, LLC. All material intercompany accounts have been eliminated in consolidation.

Uses of Estimates in Preparation of Financial Statements

The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The areas subject to significant estimates and judgement include, among others, those related to the fair value of equity awards, research and development expenses, useful lives of property and equipment, income taxes, and our valuation allowance on our deferred tax assets. On an ongoing basis we evaluate our estimates and base our estimates on historical experience and other relevant assumptions that we believe are reasonable under the circumstances.circumstances, including as a result of new information that may emerge concerning the coronavirus pandemic. We have made estimates of the impact of the coronavirus pandemic within our financial statements and there may be changes to those estimates in future periods. Actual results could differ materially from these estimates. The areas subject to significant estimates and judgement include, among others, those related to fair value of equity awards, research and development expenses, right of use lease assets, the fair value of financial instruments, useful lives of property and equipment, income taxes, and our valuation allowance on our deferred tax assets.

Restricted Cash

Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards.

Concentrations of Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash. The Company maintains cash balances in several accounts with a financial institution that management believes is creditworthy, which at times are in excess of federally insured limits. These accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $250,000 per institution.

Property and Equipment

Property and equipment are stated at cost and depreciated using the straight-line method based on the estimated useful lives of the related assets. The Company has established guidelinesprovides for depreciation over the assets’ estimated useful lives as follows:

Depreciation and amortization expense for the years ended December 31, 2020 and 2019 was $72,000 and $67,000, respectively.

Impairment of Long-Lived Assets

The Company reviews long-lived assets for impairment whenever an event occurs or change in circumstances that the related to credit ratingscarrying amounts may not be recoverable. An impairment loss would be recognized based on the difference between the carrying value of the asset and maturities intended to safeguard principal balances and maintain liquidity.its estimated fair value, which would be determined based on either discounted future cash flows or other appropriate fair value methods. The Company believes no impairment existed as of December 31, 2020 or 2019.