Atea Pharmaceuticals, Inc. - Quarter Report: 2022 March (Form 10-Q)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

For the quarterly period ended March 31, 2022

OR

For the transition period from _______________ to _______________

Commission File Number: 001-39661

ATEA PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in its Charter)

(857) 284-8891

(Registrant’s telephone number, including area code)

125 Summer Street, Boston, MA 02110

(Former name, former address and former fiscal year, if changed since last report)

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

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, 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 is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of May 5, 2022, the registrant had 83,257,591 shares of common stock, $0.001 par value per share, outstanding.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q contains forward-looking statements. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our clinical results and other future conditions. The words “aim,” “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “goal,” “intend,” “may,” "on track," “plan,” “possible,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will,” “would” or the negative of these terms or other similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

These forward-looking statements include, among other things, statements about:

These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Factors that may cause actual results to differ materially from current expectations include the initiation, execution and completion of clinical trials, uncertainties surrounding the timing of availability of data from our clinical trials, ongoing discussions with and actions by regulatory authorities, our development activities and those other factors we discuss in Part II, Item 1A. “Risk Factors.” You should read these factors and the other cautionary statements made in this report as being applicable to all related forward-looking statements wherever they appear in this report. These risk factors are not exhaustive and other sections of this report may include additional factors which could adversely impact our business and financial performance. Given these uncertainties, you should not rely on these forward-looking statements as predictions of future events. Except as required by law, we assume no obligation to update or revise these forward-looking statements for any reason, even if new information becomes available in the future.

As used in this Quarterly Report on Form 10-Q, unless otherwise specified or the context otherwise requires, the terms “we,” “our,” “us,” the “Company” refer to Atea Pharmaceuticals, Inc. and its subsidiary. All brand names or trademarks appearing in this Quarterly Report on Form 10-Q are the property of their respective owners.

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SUMMARY RISK FACTORS

Our business is subject to numerous risks and uncertainties, including those described in Part I, Item 1A. “Risk Factors” in this Quarterly Report on Form 10-Q. The principal risks and uncertainties affecting our business include the following:

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Table of Contents

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PART I—FINANCIAL INFORMATION

Item 1. Financial Statements.

ATEA PHARMACEUTICALS, INC. and Subsidiary

Condensed Consolidated Balance Sheets

(in thousands, except share and per share amounts)

(Unaudited)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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ATEA PHARMACEUTICALS, INC. and Subsidiary

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss)

(in thousands, except share and per share amounts)

(Unaudited)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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ATEA PHARMACEUTICALS, INC. and Subsidiary

Condensed Consolidated Statements of Stockholders’ Equity

(in thousands, except share amounts)

(Unaudited)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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ATEA PHARMACEUTICALS, INC. and Subsidiary

Condensed Consolidated Statements of Cash Flows

(in thousands)

(Unaudited)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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ATEA PHARMACEUTICALS, INC. and Subsidiary

Notes to Condensed Consolidated Financial Statements

(in thousands, except share and per share amounts)

(Unaudited)

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations together with our unaudited condensed consolidated financial statements and related notes included elsewhere in this Quarterly Report on Form 10-Q, as well as our audited consolidated financial statements and related notes as disclosed in our Annual Report on Form 10-K, dated December 31, 2021, filed with the Securities and Exchange Commission (“SEC”) on February 28, 2022. This discussion contains forward-looking statements based upon current plans, expectations and beliefs involving risks and uncertainties. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth in Part II, Item 1A, “Risk Factors” and other factors set forth in other parts of this Quarterly Report on Form 10-Q.

Overview

We are a clinical stage biopharmaceutical company focused on discovering, developing and commercializing antiviral therapeutics to improve the lives of patients suffering from severe viral infections. Leveraging our deep understanding of antiviral drug development, nucleos(t)ide biology, and medicinal chemistry, we have built a proprietary purine nucleos(t)ide prodrug platform to develop novel product candidates to treat single stranded ribonucleic acid viruses, which are a prevalent cause of severe viral diseases. Currently, we are focused on the development of orally available, potent, and selective nucleos(t)ide prodrugs for difficult to treat, life-threatening viral infections, including SARS-CoV-2, the virus that causes COVID-19, dengue virus, chronic hepatitis C infection (“HCV”), and respiratory syncytial virus (“RSV”).

COVID 19 – Bemnifosubvir

Our most advanced product candidate for the treatment of COVID-19 is an investigational, novel, orally administered guanosine nucleotide analog polymerase inhibitor. Bemnifosbuvir has a unique dual mechanism of action at both the RNA-dependent RNA polymerase (RdRp) and NiRAN active sites on the highly conserved SARS-CoV-2 RNA polymerase.

Topline Efficacy Results from the MORNINGSKY Trial: In a topline analysis of data from the MORNINGSKY trial, the primary endpoint, time to symptom alleviation, was not achieved. However, a 71% reduction in hospitalization (2.9% versus 10%) was observed (p=0.047, unadjusted, exploratory) in the bemnifosbuvir arm (n=137) versus placebo (n=70). There were no deaths in the trial.

The study enrolled a broad patient population of whom approximately 50% were high risk; 50% were standard risk; 28% of patients were vaccinated; and 56% were seropositive at baseline. Consistent with previous studies, bemnifosbuvir was generally well tolerated. Adverse events leading to treatment discontinuation were 3% for bemnifosbuvir versus 7% for placebo and there were no gastrointestinal-related events leading to treatment discontinuation.

MORNINGSKY was a randomized, double-blind, multi-center, placebo-controlled Phase 3 trial designed to evaluate the antiviral activity, safety and pharmacokinetics of bemnifosbuvir in up to 1,400 patients randomized 2:1 to receive bemnifosbuvir 550 mg twice-daily (BID) or placebo in an outpatient setting. The study was closed out early in December 2021 having enrolled and treated 216 patients of which 207 were evaluable for efficacy. Atea plans to present the full results of this study at an upcoming scientific meeting.

Final Analysis from Phase 2 Hospitalized Study in High-Risk Patients with COVID-19: Final clinical efficacy results from the Phase 2 hospitalized study in high-risk patients with COVID-19 (n=83) suggest potential clinical benefits. The overall rate of disease progression was low, which had an impact on the ability to assess the primary endpoint of progression of respiratory insufficiency (PRI) rate, showing a 7.5% PRI rate for bemnifosbuvir versus a 10% PRI rate for placebo (primary endpoint). There were three deaths in the study, no deaths reported with patients treated with bemnifosbuvir versus three deaths with placebo (secondary endpoint).

Final virology results in 83 patients (secondary endpoint) were consistent with previously reported interim data of 62 evaluable patients from this study. Bemnifosbuvir was generally well tolerated with no drug related serious adverse events and no adverse events leading to treatment discontinuation were observed. The sample size evaluated was insufficient for statistical comparisons.

The global Phase 2 trial was a randomized, double-blind, placebo-controlled, multi-center study to evaluate bemnifosbuvir in patients with moderate COVID-19 in the hospital setting. The key inclusion criteria for this study were adult patients over 18 years and older with risk factors such as obesity, diabetes and hypertension. Study objectives were to assess safety, tolerability, and clinical and antiviral efficacy. Patients in Cohort A were

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randomized within five days of symptom onset to receive either bemnifosbuvir 550 mg BID or placebo and were dosed for five days. An additional cohort evaluating bemnifosbuvir 1100 mg BID versus placebo enrolled a very small number of patients prior to closing out early due to the evolving nature of the standard of care in the hospital setting.

Next Steps for Bemnifosbuvir Clinical Development for COVID-19: In light of the new MORNINGSKY outpatient and Phase 2 hospitalized data for bemnifosbuvir, we are pursuing interactions with regulatory authorities to review the data package and to discuss the next steps in our clinical development program for COVID-19.

HCV – Bemnifosbuvir in combination with ruzasvir

For the treatment of chronic HCV infection, we are advancing a novel combination of bemnifosbuvir and ruzasvir, an investigational nonstructural protein 5A (“NS5A”) inhibitor that we exclusively in-licensed from Merck in December 2021. As single agents, both bemnifosbuvir and ruzasvir have demonstrated potent pan-genotypic antiviral activity against HCV. We are currently manufacturing clinical trial supplies of ruzasvir and are evaluating clinical trial designs for a Phase 2 combination study of bemnifosbuvir and ruzasvir.

Dengue – AT-752

Dengue is a mosquito-borne viral infection that infects up to 400 million people worldwide a year, causing substantial public health and economic burden. Currently there are no antiviral therapies approved by either the U.S. Food and Drug Administration (“FDA”) or the European Commission. To address this unmet medical need, we are developing AT-752, an oral, purine nucleotide prodrug product candidate for the treatment of dengue. AT-752 targets the inhibition of the dengue viral polymerase and, in preclinical studies, the drug candidate showed potent in vitro activity against all dengue serotypes tested, as well as potent in vivo antiviral activity in small animal models.

We have initiated the global Phase 2 DEFEND-2 (DEngue Fever END) study of AT-752 for the treatment of dengue. The randomized, double-blind, placebo-controlled study will evaluate multiple doses of AT-752 and enroll up to 60 adult patients infected with dengue. The primary objective of the study is to evaluate antiviral activity, with change from baseline in dengue virus (DENV) viral load as the primary endpoint [DENV RNA by reverse transcription-polymerase chain reaction (RT-PCR)].

In addition to the DEFEND-2 study, we have initiated a dengue human challenge trial. This trial, which is being conducted exclusively in the United States, is designed to evaluate the effect of AT-752 in healthy volunteers who are challenged with an attenuated DENV-1 virus strain after receiving AT-752 or placebo.

Roche collaboration

In October 2020, we entered into a License Agreement (the “Roche License Agreement”) with F. Hoffmann-LaRoche Ltd. and Genentech, Inc. (together, “Roche”) under which we granted an exclusive license for certain development and commercialization rights related to bemnifosbuvir outside of the United States (other than for certain HCV uses) to Roche. As partial consideration, Roche paid us an upfront payment of $350.0 million which was received in November 2020. Additionally, upon realization of a development milestone in June 2021, we received an additional $50.0 million from Roche.

In November 2021, we received notice from Roche that they had elected to terminate the Roche License Agreement in its entirety on a worldwide basis including Japan, with an effective date of February 10, 2022. In December 2021, we delivered to Roche notice that we intended to continue the development of bemnifosbuvir and we have been working with Roche to effect an orderly wind down of activities in accordance with the terms of the Roche License Agreement. The obligations of Roche to equally share the costs associated with development activities terminated on February 10, 2022. We are now responsible for, and alone will bear the costs associated with the development of bemnifosbuvir. Additionally, we remain liable to Roche for certain expenses associated with transition related activities occurring after the effective date of the termination of the Roche License Agreement.

As a result of the termination of the Roche License Agreement, we have regained worldwide exclusive rights from Roche to research, develop, manufacture and commercialize bemnifosbuvir in all fields of use.

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Financial Operations Overview

As of March 31, 2022, we had cash and cash equivalents of $705.5 million. Net cash used in operating activities was $59.0 million for the three months ended March 31, 2022.

We expect that our net cash used in operating activities will increase significantly as we advance our product candidates through preclinical and clinical development, seek regulatory approval, and prepare for and, if approved, proceed to commercialization; acquire, discover, validate and develop additional product candidates; obtain, maintain, protect and enforce our intellectual property portfolio; and hire additional personnel. In addition, we may incur additional costs as we continue to operate as a public company. We believe that our available cash and cash equivalents will be sufficient to fund our planned operations through at least 2025.

We do not have any products approved for sale and have not generated any product revenue since inception. We do not anticipate generating any revenue from product sales for the foreseeable future. Our ability to generate product revenue will depend on the successful development, regulatory approval and eventual commercialization of one or more of our product candidates. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through private or public equity or debt financings, collaborative or other arrangements with corporate sources, or through other sources of financing. Adequate funding may not be available to us on acceptable terms, or at all. If we fail to raise capital or enter into such agreements as and when needed, we may have to significantly delay, scale back or discontinue the development and commercialization of our product candidates.

We plan to continue to use third-party service providers, including contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), to carry out our preclinical and clinical development and to manufacture and supply the materials to be used during the development and commercialization of our product candidates.

As we continue to advance our programs, we expect to incur significantly higher expenses over the next several years. We anticipate that our expenses will increase significantly in connection with our ongoing activities, as we:

Components of Results of Operations

Revenue

To date, we have not generated any revenue from product sales. Our revenue has been collaboration revenue solely derived from the Roche License Agreement, which was terminated in February 2022. If our development efforts for our product candidates are successful and result in commercialization, we may generate additional revenue in the future from a combination of product sales or payments from collaboration or license agreements that we may enter into with third parties.

Operating Expenses

Research and Development Expenses

Substantially all of our research and development expenses consist of expenses incurred in connection with the development of our product candidates. These expenses include fees paid to third parties, including CROs and CMOs, to conduct certain research and development activities on our behalf, consulting costs, certain payroll and personnel-related expenses, including salaries and bonuses, employee benefit costs and stock-based compensation expenses for our research and product development employees and allocated overhead, including rent, equipment, depreciation, information technology costs and utilities attributable to research and development

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personnel. We expense both internal and external research and development expenses as they are incurred. In circumstances where amounts have been paid in advance or in excess of costs incurred, we record a prepaid expense, which is expensed as services are performed or goods are delivered.

A significant portion of our research and development costs have been external costs, which we track by therapeutic area. Our internal research and development costs are primarily personnel-related costs, including stock-based compensation, facility costs, including depreciation and lab consumables. We have not historically tracked our internal research and development expenses by therapeutic area as they are deployed across multiple programs.

As discussed in Note 3 to our unaudited condensed consolidated financial statements, during the term of the Roche License Agreement which terminated in February 2022, we and Roche shared certain manufacturing and clinical development costs on a 50/50 basis. Billings to us by Roche for our percentage share of such expenses are recorded in research and development expenses. While these costs represented a material portion of our total expenses through March 31, 2022 we do not expect such costs to be a material portion of our global expenses in the future.

The following table summarizes our external research and development expenses by indication and internal research and development expenses:

We are focusing substantially all of our resources on the development of our product candidates, particularly bemnifosbuvir. We expect our research and development expenses to increase substantially for at least the next few years, as we seek to initiate additional clinical trials for our product candidates, complete our clinical programs, pursue regulatory approval of our product candidates and prepare for the possible commercialization of these product candidates. Predicting the timing or cost to complete our clinical programs or validation of our commercial manufacturing and supply processes is difficult and delays may occur because of many factors, including factors outside of our control. For example, if the FDA or other regulatory authorities were to require us to conduct clinical trials beyond those that we currently anticipate, we could be required to expend significant additional financial resources and time on the completion of clinical development. Furthermore, we are unable to predict when or if our product candidates will receive regulatory approval with any certainty.

General and Administrative Expenses

General and administrative expenses consist principally of payroll and personnel expenses, including salaries and bonuses, benefits and stock-based compensation expenses, professional fees for legal, consulting, accounting and tax services, allocated overhead, including rent, equipment, depreciation, information technology costs and utilities, and other general operating expenses not otherwise classified as research and development expenses.

We anticipate that our general and administrative expenses may increase as a result of increased personnel costs, expanded infrastructure and higher consulting, legal and accounting services costs associated with complying with Nasdaq and SEC requirements, investor relations costs and director and officer insurance premiums associated with being a public company.

Interest Income and Other, Net

Interest income and other, net, consists primarily of interest income earned on our cash and cash equivalents.

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Results of Operations

Comparison of the Three Months Ended March 31, 2022 and 2021

The following table summarizes our results of operations for the periods indicated:

Revenue

Collaboration revenue for the three months ended March 31, 2021 was derived from the Roche License Agreement that was executed in October 2020 and terminated in February 2022. As discussed in Note 3 to our unaudited condensed consolidated financial statements included elsewhere in this Quarterly Report on Form 10-Q, following receipt in November 2021 of the notice from Roche terminating the agreement, the Company recognized all remaining revenue and consequently we had no collaboration revenue for the three months ended March 31, 2022.

Research and Development Expenses

Research and development expenses increased by $3.1 million from $26.6 million for the three months ended March 31, 2021 to $29.7 million for the three months ended March 31, 2022. Research and development expenses primarily consists of external expenses incurred related to services provided by the CROs and CMOs in conjunction with the advancement of product candidates, including $9.6 million and $14.5 million for the three months ended March 31, 2022 and 2021, respectively, related to our share of costs incurred by Roche. In addition, increase in internal spend consists primarily of salaries and bonuses, benefits and stock-based compensation expense of $2.2 million for our research and product development employees and consulting fees and other research and development expenses. Research and development expenses include a reduction of $0.9 million and $3.4 million, respectively, representing Roche’s share of certain expenses we incurred that are subject to ASC 808 as discussed in Note 3 to our unaudited condensed consolidated financial statements for the three months ended March 31, 2022 and 2021.

General and Administrative Expenses

General and administrative expenses increased by $3.7 million from $8.8 million for the three months ended March 31, 2021 to $12.5 million for the three months ended March 31, 2022. The increase in general and administrative expenses was primarily due to the expansion of our organization resulting in an increase in payroll and personnel-related expenses of $2.4 million, including salaries, benefits and stock-based compensation expense of $2.1 million and an increase in other general and administrative expenses of $0.8 million.

Interest Income and Other, Net

Interest income and other, net, remained substantially consistent during the three months ended March 31, 2022 compared to the three months ended March 31, 2021.

Income Tax Expense

Income tax expense was $0 for the three months ended March 31, 2022 and 2021.

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Liquidity and Capital Resources

Sources of Liquidity

As of March 31, 2022, we had cash and cash equivalents of $705.5 million. We believe that our available cash and cash equivalents will be sufficient to fund our planned operations through at least 2025.

Future Funding Requirements

To date, we have not generated any product revenue. We do not expect to generate any product revenue unless and until we obtain regulatory approval of and commercialize any of our product candidates and we do not know when, or if, this will occur. We expect to continue to incur increased expenditures for the foreseeable future, and we expect our expenses to increase as we continue the development of, and seek regulatory approvals for, our product candidates and begin to commercialize any approved products. We are subject to all of the risks typically related to the development of new product candidates, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. Moreover, we may incur additional general and administrative costs as we continue to operate as a public company.

We will continue to require additional capital to develop our product candidates and fund operations for the foreseeable future. We may seek to raise capital through public or private equity or debt financings, collaborative or other arrangements with corporate sources, or through other sources of financing. We anticipate that we may need to raise substantial additional capital, the requirements for which will depend on many factors, including:

A change in the outcome of any of these or other variables with respect to the development of any of our product candidates could significantly change the costs and timing associated with the development of that product candidate. Furthermore, our operating plans may change in the future, and we will continue to require additional capital to meet operational needs and capital requirements associated with such operating plans. If we raise additional funds by issuing equity securities, our stockholders may experience dilution. Any future debt financing into which we enter may impose upon us additional covenants that restrict our operations, including limitations on our ability to incur liens or additional debt, pay dividends, repurchase our common stock, make certain investments or engage in certain merger, consolidation or asset sale transactions. Any debt financing or additional equity that we raise may contain terms that are not favorable to us or our stockholders.

Adequate funding may not be available to us on acceptable terms or at all. Our failure to raise capital as and when needed could have a negative impact on our financial condition and our ability to pursue our business strategies. If we are unable to raise additional funds when needed, we may be required to delay, reduce, or

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terminate some or all of our development programs and clinical trials or we may also be required to sell or license to others rights to our product candidates in certain territories or indications that we would prefer to develop and commercialize ourselves. If we are required to enter into collaborations and other arrangements to supplement our funds, we may have to give up certain rights that limit our ability to develop and commercialize our product candidates or may have other terms that are not favorable to us or our stockholders, which could materially affect our business and financial condition.

See Part II, Item 1A,“Risk Factors” for additional risks associated with our substantial capital requirements.

Summary Statement of Cash Flows

The following table sets forth the primary sources and uses of cash, cash equivalents, and restricted cash for each of the periods presented below:

Cash Flows from Operating Activities

Net cash used in operating activities for the three months ended March 31, 2022 was $59.0 million. Cash used in operating activities was primarily due to net loss of $42.1 million partially offset by stock-based compensation of $11.7 million, a decrease in accounts payable and accrued expenses of $28.9 million and a decrease in prepaid and other current assets of $0.3 million.

Net cash used in operating activities for the three months ended March 31, 2021 was $16.8 million. Cash used in operating activities was primarily due to research and development expenses of $26.6 million and general and administrative expenses of $8.8 million, partially offset by stock-based compensation of $7.3 million, an increase in accounts payable and accrued expenses of $10.4 million, an increase in other assets of $0.3 million and a decrease in prepaid expenses of $1.2 million. The Company recognized revenue of $66.0 million for the three months ended March 31, 2021. The revenue recognized did not have an impact on net cash used in operating activities as this amount was previously included in deferred revenue as of December 31, 2020.

Cash Flows from Investing Activities

Cash used in investing activities for the three months ended March 31, 2022 was less than $0.1 million and consisted of purchases of fixed assets. There were no cash flows from investing activities for the three months ended March 31, 2021.

Cash Flows from Financing Activities

Net cash provided by financing activities was $0.2 million and $0.5 million for the three months ended March 31, 2022 and 2021, respectively, and consisted of proceeds from the exercise of stock options.

Contractual Obligations and Commitments

There have been no material changes to our contractual obligations during the three months ended March 31, 2022 from those previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2021.

We enter into contracts in the normal course of business with third-party contract organizations including CROs and CMOs for preclinical and clinical studies and testing, manufacture and supply of our preclinical materials and other services and products used for operating purposes. These contracts do not contain any minimum purchase commitments and generally provide for termination following a certain period after notice, and therefore we believe that our non-cancelable obligations under these agreements are not material. Payments due upon cancelation consist only of payments for services provided and expenses incurred up to the date of cancelation.

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Critical Accounting Policies and Estimates

Our financial statements have been prepared in accordance with GAAP. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

Our critical accounting policies and estimates are described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our Annual Report on Form 10-K for the year ended December 31, 2021. We believe that these accounting policies are critical to understanding our historical and future performance, as these policies relate to significant areas involving management’s judgments and estimates. During the three months ended March 31, 2022 there were no material changes to our critical accounting policies from those discussed in our Annual Report on Form 10-K.

Indemnification Agreements

We enter into standard indemnification arrangements in the ordinary course of business. Pursuant to these arrangements, we indemnify, hold harmless and agree to reimburse the indemnified parties for losses suffered or incurred by the indemnified party, including in connection with any trade secret, copyright, patent or other intellectual property infringement claim by any third party with respect to its technology. The term of these indemnification agreements is generally perpetual any time after the execution of the agreement. The maximum potential amount of future payments we could be required to make under these arrangements is not determinable. We have never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, we believe the fair value of these agreements is minimal.

We have also agreed to indemnify our directors and officers for certain events or occurrences while the director or officer is, or was serving, at our request in such capacity. The indemnification period covers all pertinent events and occurrences during the director’s or officer’s service. The maximum potential amount of future payments we could be required to make under these indemnification agreements is not specified in the agreements; however, we have director and officer insurance coverage that reduces our exposure and enables us to recover a portion of any future amounts paid. We believe the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal.

Recent Accounting Pronouncements

See the section titled “Summary of Significant Accounting Policies—Recent Accounting Pronouncements” in Note 2 to our unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q for additional information.

Item 3. Quantitative and Qualitative Disclosures About Market Risk.

Interest Rate Sensitivity

The market risk inherent in our financial instruments and in our financial position represents the potential loss arising from adverse changes in interest rates or exchange rates. As of March 31, 2022, we had cash and cash equivalents of $705.5 million, consisting of interest-bearing money market funds for which the fair value would be affected by changes in the general level of U.S. interest rates. However, due to the short-term maturities and the low-risk profile of our cash equivalents, an immediate 10% relative change in interest rates would not have a material effect on the fair value of our cash equivalents or on our future interest income.

We do not believe that inflation, interest rate changes or foreign currency exchange rate fluctuations have had a significant impact on our results of operations for any periods presented herein.

Item 4. Controls and Procedures.

Limitations on effectiveness of controls and procedures

In designing and evaluating our disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving

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the desired control objectives. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Evaluation of disclosure controls and procedures

Our management, with the participation of our principal executive officer and principal financial officer, evaluated, as of the end of the period covered by this Quarterly Report on Form 10-Q, the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Based on that evaluation, our principal executive officer and principal financial officer concluded that, as of March 31, 2022, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the quarter ended March 31, 2022 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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PART II—OTHER INFORMATION

Item 1. Legal Proceedings.

We are not subject to any material legal proceedings.

Item 1A. Risk Factors.

You should carefully consider the risks and uncertainties described below, as well as the other information in this Quarterly Report on Form 10-Q, including our unaudited condensed consolidated financial statements and the related notes and “Management’s Discussion and Analysis of Results of Operations and Financial Condition.” Our business, financial condition, results of operations or prospects could be materially and adversely affected if any of these risks occurs, and as a result, the market price of our common stock could decline and you could lose all or part of your investment. Our actual results could differ materially and adversely from those anticipated in these forward-looking statements as a result of certain factors, including those set forth below.

Risks Related to COVID-19

There is significant uncertainty around our development of bemnifosbuvir as a potential treatment for COVID-19.

Our development of bemnifosbuvir for the treatment of COVID-19 is in its early stages, and we may not be successful in our development of bemnifosbuvir as a potential treatment for COVID-19. In October 2020, we entered into a license agreement (as amended, the “Roche License Agreement”) with F. Hoffmann-LaRoche Ltd. and Genentech, Inc. (together, “Roche”) under which we granted to Roche an exclusive license to development and commercialization rights related to certain of our compounds, including bemnifosbuvir, outside of the United States (other than for certain HCV uses). Together with Roche, in April 2021, we initiated a randomized, double blind, multi-center, placebo-controlled Phase 3 clinical trial to study bemnifosbuvir in adult and adolescent patients with mild or moderate COVID-19 in the outpatient setting (“MORNINGSKY”) and we subsequently initiated a Phase 3 six month follow-up study (“MEADOWSPRING”) to assess the impact of bemnifosbuvir treatment on long-term sequelae of COVID-19 in the patients previously enrolled in MORNINGSKY. The Phase 3 clinical trials were begun while two Phase 2 clinical trials evaluating bemnifosbuvir in patients with COVID1-19 were ongoing. One of these Phase 2 clinical trials enrolled hospitalized patients and the other Phase 2 clinical trial (MOONSOONG) enrolled outpatients. In October 2021, we, together with Roche, completed MOOONSONG, and we announced that we did not meet the primary endpoint of reduction from baseline in the amount of SARS-CoV-2 virus in patients with mild or moderate COVID-19 compared to placebo in the overall study population, of which approximately two-thirds of enrolled patients were low-risk with mild symptoms. In November 2021, Roche notified us that it was terminating the Roche License Agreement effective February 10, 2022. In December 2021 due to the changing COVID-19 treatment landscape, including the availability of new oral antiviral treatment regimens, we determined to discontinue each of the phase 3 MORNINGSKY and MEADOWSPRING clinical trials. We did not enroll a sufficient number of patients in either study to conduct prespecified statistical analyses. In January 2022 we determined to close out the Phase 2 clinical trial in hospitalized patients.

In May 2022, we reported topline results from the MORNINGSKY trial and the final analysis of data from the Phase 2 clinical trial in high-risk hospitalized patients.

In the topline analysis of data from the MORNINGSKY trial, the primary endpoint, time to symptom alleviation, was not achieved. However, a 71% reduction in hospitalization (2.9% versus 10%) was observed (p=0.047, unadjusted, exploratory) in the bemnifosbuvir arm (n=137) versus placebo (n=70). There were no deaths in the MORNINGSKY trial.

Final clinical results from the Phase 2 study in high-risk hospitalized patients (n=83) suggest potential clinical benefits. The overall rate of disease progression was low, which had an impact on the ability to assess the primary endpoint of progression of respiratory insufficiency (PRI) rate, showing a 7.5% PRI rate for bemnifosbuvir 550 mg BID versus a 10% PRI rate for placebo (primary endpoint). There were three deaths in the study, no deaths were reported with patients treated with bemnifosbuvir versus three deaths reported with placebo. Final virology results (secondary endpoint) were consistent with previously reported interim data from this study. Bemnifosbuvir was generally well tolerated with no drug related serious adverse events and no adverse events leading to treatment discontinuation.

Given these results, we are currently evaluating the pathway for development of bemnifosbuvir for the treatment of COVID-19 and may determine to pursue either or both of a mono- and combination therapy strategy. We do not know if either of these approaches will be successful. In addition, clinical trials evaluating combination

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regimens will be subject to additional risks, including the potential requirement to sufficiently demonstrate the effect, if any, of each constituent component of the combination regimen to the satisfaction of the United States Food and Drug Administration (“FDA”) or other regulatory authorities.

We have not acquired or developed any agents that may be combined with bemnifosbuvir in a combination therapy. We have begun to internally develop a potential protease inhibitor to evaluate in combination with bemnifosbuvir. These efforts are at a very early stage and we do not know if such efforts will be successful, or if successful, when a protease inhibitor product candidate generated from our discovery efforts may be permitted to enter clinical development. Alternatively, we may in-license or acquire the rights to develop and commercialize a protease inhibitor drug candidate from a third party. Proposing, negotiating and implementing acquisition or in-license of a protease inhibitor or any other product candidate that may be combined with bemnifosbuvir may be a lengthy and complex process. Other companies, including those with substantially greater financial, marketing and sales resources, may compete with us for the acquisition of such product candidates. We may not be able to acquire the rights to additional product candidates on terms that we find acceptable, if at all

We have committed and plan to continue to commit significant financial and personnel resources to the development of bemnifosbuvir as either or both of a mono- and combination therapy (together, a “bemnifosbuvir COV19 product candidate”) as a potential treatment for COVID-19. If we are unable to successfully develop a bemnifosbuvir COV19 product candidate for the treatment of COVID-19, we will have taken resources away from other development programs and will not be able to recuperate the resources dedicated to developing a bemnifosbuvir COV19 product candidate as a potential treatment for COVID-19, which could have a material adverse impact on our business. If we are able to initiate clinical development of the bemnifosbuvir COV19 product and the data from our clinical trials are not supportive of further development or commercialization of such bemnifosbuvir COV19 product candidate as a treatment for COVID-19, or the investor community otherwise has a negative reaction to the data, the demand for our common stock could decrease significantly, and the price of our common stock could decline substantially, which could result in significant losses for our stockholders.

Further, while we believe there is currently an urgent need for treatments for COVID-19, the longevity and extent of the ongoing COVID-19 pandemic is uncertain and it is unclear whether SARS-CoV-2 will become an endemic human coronavirus that may circulate in the human population after the current pandemic has subsided. If the pandemic were to dissipate, whether due to a significant decrease in the number or severity of new infections, the effectiveness of vaccines, the effectiveness of other treatment options, or otherwise, the need for treatments could decrease significantly. If the need for a treatment decreases before or soon after commercialization of a bemnifosbuvir COV19 product candidate, if successfully developed and approved, our business could be adversely impacted.

A bemnifosbuvir COV19 product candidate, even if successfully developed and approved, may face significant competition from other treatments and vaccines for COVID-19 which have been authorized or approved for use or are in development.

Many biotechnology and pharmaceutical companies are developing treatments for COVID-19 or vaccines against SARS-CoV-2, the virus that causes COVID-19. Many of these companies, which include large pharmaceutical companies, have greater resources for development and established commercialization capabilities. For example, in November 2021, molnupiravir, an orally administered direct-acting antiviral, being developed by Merck and Ridgeback Biotherapeutics (“Ridgeback”) for the treatment of adults with mild to moderate COVID-19 in the outpatient setting received conditional marketing authorization for use from the health authorities in the United Kingdom. In December 2021, the FDA issued an emergency use authorization for molnupiravir for the treatment of mild-to-moderate COVID-19 in certain adults who are at high-risk for progression to severe COVID-19, including hospitalization or death. Merck and Ridgeback are currently seeking similar authorizations from numerous other global health authorities. In December 2021, the FDA issued an emergency use authorization for Paxlovid, an orally administered direct-acting antiviral being developed by Pfizer Inc. (“Pfizer”) consisting of nirmatrelvir, a protease inhibitor, and ritonavir, for the treatment of adults with mild to moderate COVID-19 in the outpatient setting. In January 2022, the European Medicines Agency recommended conditional marketing authorization for Paxlovid. Other products for the treatment of COVID-19 are currently authorized for use or approved by health regulatory authorities in numerous countries throughout the world. These products include the antiviral drug Veklury (remdesivir), a direct acting antiviral marketed by Gilead Sciences for the treatment of COVID-19 for certain patients requiring hospitalization and sotrovimab, a monoclonal antibody for the treatment of high risk adults and adolescents with mild to moderate COVID-19 for which VIR Biotechnology, Inc. and GlaxoSmithKline have received emergency use authorization from the FDA. In addition to therapeutics, vaccines indicated for active immunization to prevent COVID-19 have been authorized by the FDA. In August 2021, the FDA approved vaccines from Pfizer and BioNTech and Moderna, Inc. (“Moderna”), each of which were found to

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be more than 90% effective in preventing COVID-19 during clinical trials. In addition, in February 2021, the FDA granted emergency use authorization to a vaccine developed by Janssen Pharmaceutical Company (“Janssen”). Each of Pfizer and BioNTech, Moderna and Janssen have also created, developed and received regulatory authorization in a number of jurisdictions for the use of vaccine “boosters,” which are intended to extend the immunizing effect initiated with the administration of the initial vaccine regimen. Additional vaccines and therapeutics are in development by other pharmaceutical and biopharmaceutical companies. Given the products currently approved or authorized for use as well as those in development by others, any treatment we may develop could face significant competition. If we are unable to develop a treatment that can be distinguished based on efficacy, safety, cost or other factors from the growing number of treatments for COVID-19 or if any treatment becomes the standard of care, can be administered at a lower cost, or is more successful at commercializing an approved treatment, we may not be able to successfully commercialize a bemnifosbuvir COV19 product for the treatment of COVID-19, even if approved, or compete with other treatments or vaccines, which would adversely impact our business and operations.

The COVID-19 pandemic may materially and adversely affect our business and financial results.

The global emergence of variants and subvariants of SARS-CoV-2, including the Delta and Omicron variant and subvariants such as BA.2 and BA.2.12.1 and more recently BA.4 and BA.5, has resulted in an increasing number of infections, including breakthrough infections in persons who have been vaccinated against the infection. In the United States, travel bans and government stay-at-home orders in response to the initial outbreak caused widespread disruption in business operations and economic activity. Governmental authorities around the world implemented measures to reduce the spread of COVID-19. These measures, including suggested or mandated “shelter-in-place” orders, adversely affected workforces, customers, consumer sentiment, economies, and financial markets, and, along with decreased consumer spending, contributed to an economic downturn in the United States. Future resurgences in cases may result in renewal of measures, now being increasingly relaxed, intended to reduce the spread of COVID-19. In response to the public health directives and orders and to help minimize the risk of COVID-19 for our employees, we have taken precautionary measures, including implementing work-from-home policies for all our employees. Many of our third-party collaborators, such as our CMOs, clinical research organizations (“CROs”), suppliers and others, have taken similar precautionary measures. At times during the pandemic, these measures have disrupted our business and delayed certain of our clinical programs and timelines. For example, our Phase 1/2a clinical trial in patients with hepatitis C virus (“HCV”) was paused when clinical trial sites closed due to COVID-19 precautions by the countries and medical facilities where the trial was to be conducted.

The impact to our operations due to elongation of the COVID-19 pandemic could be severe and could negatively affect our business, financial condition and results of operations. To the extent the COVID-19 pandemic adversely affects our business and financial results, it may also have the effect of heightening many of the other risk factors described in this “Risk Factors” section, such as those relating to our clinical trial timelines, our ability to enroll subjects for clinical trials and obtain materials that are required for the manufacture of our product candidates, and our ability to raise capital.

The COVID-19 pandemic may materially and adversely affect our clinical trials.

As a result of the COVID-19 pandemic, we may experience additional disruptions that could severely impact our clinical trials, including but not limited to:

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The symptoms, progression, and transmission of COVID-19 resulting from infection with a particular variant, as evidenced with Delta or Omicron variants differ in multiple ways including severity of symptoms and rate of transmissibility. This rapid and continuing emergence of variants and the evolution of disease manifestation presents additional challenges for the conduct of our clinical trials in COVID-19 patients. For example, COVID-19 patients have presented with a wide range of symptoms and side effects, which may make it more difficult for clinical trial investigators to determine whether any adverse events observed in our clinical trials are related to bemnifosbuvir or are consistent with the underlying disease. Any increase in the severity or incidence of adverse events deemed to be related to bemnifosbuvir or any combination regimen we seek to develop could delay or prevent its regulatory approval, which could have a material adverse effect on our business, financial condition and results of operations. In addition, efficacy and antiviral results from a COVID-19 clinical trial may be affected by, among other things, which variant or variants causes the infection and evolving immunization status of the patients enrolling in the clinical trial, resulting in response rates that may also be variable over time as the pandemic progresses.

Risks Related to Our Financial Condition and Capital Requirements

We have a limited operating history and no history of successfully developing or commercializing any approved antiviral products, which may make it difficult to evaluate the success of our business to date and to assess the prospects for our future viability.

We are a clinical-stage biopharmaceutical company. Our operations to date have been limited to financing and staffing our company, developing our technology and identifying and developing our product candidates. Our prospects must be considered in light of the uncertainties, risks, expenses and difficulties frequently encountered by biopharmaceutical companies in their early stages of operations. We have not yet demonstrated an ability to complete any late-stage or pivotal clinical trials, obtain marketing approval, manufacture a product at commercial-scale, or conduct sales and marketing activities necessary for successful product commercialization, or arrange for third parties to do these activities on our behalf. Consequently, predictions about our future success or viability may not be as accurate as they could be if we had a longer operating history or a history of successfully developing, obtaining marketing approval for and commercializing antiviral therapies.

In addition, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown obstacles. For example, due to changes in the COVID-19 landscape, we discontinued our Phase 3 MORNINGSKY trial in 2021. As we undertake additional development of a bemnifosbuvir COV19 product candidate, particularly if we advance a combination product, we may be required to conduct earlier-stage trials before we can advance to any late- or pivotal-stage clinical trials, and therefore will require additional time and

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resources, including the resources required to discover or acquire a product or product candidate that we can evaluate in combination with bemnifosbuvir. If we successfully develop and obtain approval of any product candidate, we will need to transition from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in this transition.

As we continue to build our business, we expect our financial condition and operating results may fluctuate significantly from quarter to quarter and year to year due to a variety of factors, many of which are beyond our control. For example, the decision by Roche to terminate the Roche License Agreement also terminated Roche’s obligation, after February 10, 2022, the effective date of the termination of the Roche License Agreement, to share with us costs associated with the development of bemnifosbuvir for the treatment of COVID-19.

Additionally, as a further result of the termination of the Roche License Agreement, we will not receive any other revenue from Roche beyond the upfront payment we received in 2020 and the milestone payment we received in 2021. Accordingly, you should not rely upon the results included in this report or any other particular prior quarterly or annual period as indications of future operating performance.

We have incurred significant operating expenses since inception and expect to incur significant additional operating expenses for the foreseeable future. We have no products that have generated any commercial revenue and we do not expect to maintain profitability in 2022 and for the foreseeable future.

We have incurred significant operating expenses since our inception. For the three months ended March 31, 2022 and the year ended December 31, 2021, our operating expenses were $42.2 million and $213.0 million, respectively. In 2021, as a result of the termination by Roche of the Roche License Agreement, which resulted in the recognition of revenue for accounting purposes associated with the deferred revenue balance associated with upfront payment and the milestone payment we received from Roche, we recorded operating income for the year ended December 31, 2021. We do not expect to maintain operating income in 2022 and for the foreseeable future.

We have not commercialized any products and have never generated any revenue from product sales. We have devoted almost all of our financial resources to research and development, including our clinical trials and preclinical development activities. We expect to continue to incur significant additional operating expenses and to incur operating losses in the remainder of 2022 and for the foreseeable future as we seek to advance product candidates through clinical development, continue preclinical development, expand our research and development activities, discover or acquire and develop new product candidates, acquire or in-license a drug or drug candidate for our bemnifosbuvir COV19 product candidate, complete preclinical studies and clinical trials, seek regulatory approval and, if we receive regulatory approval, commercialize our products.

In order to obtain the FDA’s or a foreign regulatory authority’s approval to market any product candidate in the United States or abroad, respectively, we must submit to the FDA a New Drug Application (“NDA”) or similar application to the foreign regulatory authority demonstrating to the FDA’s or foreign regulatory authority’s satisfaction that the product candidate is safe and effective for its intended use(s). This demonstration requires significant research and extensive data from animal tests, which are referred to as nonclinical or preclinical studies, as well as human tests, which are referred to as clinical trials. Furthermore, the costs of advancing product candidates into each succeeding clinical phase tend to increase substantially over time. The total costs to advance any of our product candidates to marketing approval in even a single jurisdiction would be substantial and difficult to accurately predict. Because of the numerous risks and uncertainties associated with the development of drug products, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to begin generating revenue from the commercialization of products or again achieve profitability. Our expenses will also increase substantially if or as we:

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Furthermore, our ability to successfully develop, commercialize and license any products and generate product revenue is subject to substantial additional risks and uncertainties. Each of our product candidates and any future product candidate we may discover, license or otherwise acquire, will require additional preclinical and/or clinical development, regulatory approval in not less than one jurisdiction, the securing of manufacturing supply, capacity, distribution channels and expertise, the use of external vendors, the building of a commercial organization, substantial investment and significant marketing efforts before we generate any revenue from product sales. As a result, we expect to continue to incur operating expenses and use cash for operating activities for the foreseeable future. These operating expenses and use of cash have had, and will continue to have, an adverse effect on our working capital. Additionally, we may incur operating losses in future periods.

The amount of future expenses or losses and our ability to achieve or maintain profitability in future years, if ever, are uncertain. We have no products that have generated any commercial revenue, do not expect to generate revenues from the commercial sale of products in the foreseeable future, and might never generate revenues from the sale of products. Our ability to generate product revenue and maintain profitability will depend on, among other things, successful completion of the clinical development of our product candidates; obtaining necessary regulatory approvals from the FDA and foreign regulatory authorities; establishing manufacturing and sales capabilities; market acceptance of our products, if approved, and establishing marketing infrastructure to commercialize our product candidates for which we obtain approval; and raising sufficient funds to finance our activities. We might not succeed at any of these undertakings. If we are unsuccessful at some or all of these undertakings, our business, prospects, and results of operations may be materially adversely affected.

We will require substantial additional financing, which may not be available on acceptable terms, or at all. A failure to obtain this necessary capital when needed could force us to delay, limit, reduce or terminate our product development or commercialization efforts.

Since inception, we have incurred substantial operating expenses. We expect to continue to incur substantial expenses to continue the clinical development of bemnifosbuvir COV19 product candidate for the treatment of COVID-19, the combination of bemnifosbuvir and ruzasvir for the treatment of HCV and AT-752 for the treatment of dengue. Additionally, we expect to incur significant expenses in the future in connection with clinical trials for other product candidates and in our efforts to identify new product candidates, through internal discovery efforts or through acquisition or licensing.

We will continue to need additional capital to fund future clinical trials and preclinical development, which we may raise through equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements or other sources. Additional sources of financing might not be available on favorable terms, if at all. If we do not succeed in raising additional funds on acceptable terms, we might be unable to initiate or complete planned clinical trials or seek regulatory approvals of any of our product candidates from the FDA, or any foreign regulatory authorities, and could be forced to discontinue product development. In addition, attempting to secure additional financing may divert the time and attention of our management from day-to-day activities and harm our product candidate development efforts.

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Based on our current operating plan, we believe that our cash and cash equivalents as of March 31, 2022 will be sufficient to fund our operating expenses and capital expenditure requirements through at least 2025. This estimate is based on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect. We will require significant additional funds in order to launch and commercialize our current and any future product candidates to the extent that such launch and commercialization are not the responsibility of a collaborator. In addition, other unanticipated costs may arise in the course of our development efforts. Because the design and outcome of our planned and anticipated clinical trials is highly uncertain, we cannot reasonably estimate the actual amounts necessary to successfully complete the development and, if approved, commercialization of any product candidate we develop.

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

We cannot be certain that additional funding will be available on acceptable terms, or at all. If we are unable to raise additional capital in sufficient amounts, on terms acceptable to us, or on a timely basis, we may have to significantly delay, scale back or discontinue the development or commercialization of our product candidates or other research and development initiatives.

We have not generated any revenue from product sales and may not be able to achieve profitability.

Due to the recognition of revenue for accounting purposes of certain payments we received under the terminated Roche License Agreement, we recognized operating income for the year ended December 31, 2021, however, our ability to achieve and sustain future profitability depends upon our ability to generate revenue from product sales. Other than from the Roche License Agreement, we have not generated any revenue and do not expect to generate product revenue unless or until we successfully complete clinical development and obtain regulatory approval of, and then successfully commercialize, at least one of our product candidates. Our product candidates are in varying stages of development, which may necessitate additional preclinical studies in some cases and in

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all cases will require additional clinical development as well as regulatory review and approval, substantial investment, access to sufficient commercial manufacturing capacity and significant marketing efforts before we can generate any revenue from product sales. Currently, we do not anticipate generating revenue from product sales for at least the next several years. Our ability to generate revenue depends on a number of factors, including, but not limited to:

Many of the factors listed above are beyond our control, and could cause us to experience significant delays or prevent us from obtaining regulatory approvals or commercializing our product candidates. Even if we are able to commercialize our product candidates, we may not be able to maintain profitability after generating product sales or meet outside expectations for our profitability. If we are unable to achieve or sustain profitability or to meet outside expectations for our profitability, the value of our common stock will be materially adversely affected. In addition, if we are unable to generate sufficient revenue through the sale of any products, we may be unable to continue operations.

Our ability to use our net operating loss carryforwards and other tax attributes to offset taxable income may be subject to certain limitations.

We utilized federal and state net operating loss carryforwards (“NOLs”) of approximately $52.8 million and $52.6 million, respectively, during the year ending December 31, 2021. We utilized federal and state research and development credit carryforwards of $0.7 million and $0.3 million, respectively during the year ended December 31, 2021. As of March 31, 2022, we had federal NOLs of $0.4 million which may be available to offset future taxable income, if any.

In general, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the “Code”), a corporation that undergoes an “ownership change,” generally defined as a greater than 50% change by value in its equity ownership over a three-year period, is subject to limitations on its ability to utilize its pre-change NOLs

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and its research and development credit carryforwards to offset future taxable income. Our NOLs and research and development credit carryforwards may be subject to limitations arising from previous ownership changes, and if we undergo an ownership change, our ability to utilize NOLs (to the extent not previously utilized) and research and development credit carryforwards could be further limited by Sections 382 and 383 of the Code.

We performed an analysis through December 31, 2020 pursuant to Section 382 of the Code to determine whether any limitations might exist on the utilization of NOLs and other tax attributes. Based on this analysis, we have determined that ownership changes occurred in 2014. In addition, based on publicly available statements of acquisition of beneficial ownership, we identified an ownership change on December 31, 2021 which did not have an impact on our consolidated financial statements. We are in the process of completing a Section 382 study for the fiscal year 2021, the results of which could indicate that the ownership shift occurred prior to December 31, 2021. In addition, future changes in our stock ownership, some of which might be beyond our control, could result in an ownership change under Sections 382 and 383 of the Code. For these reasons, we may not be able to utilize existing NOLs or research and development credit carryforwards or net operating losses and research and development credits that may be generated in the future.

We may delay or terminate the development of a product candidate at any time if we believe the perceived market or commercial opportunity does not justify further investment, which could materially harm our business and adversely affect our stock price.

Even if the results of preclinical studies and clinical trials that we have conducted or may conduct in the future may support further development of one or more of our product candidates, we may delay, suspend or terminate the future development of a product candidate at any time for strategic, business, financial or other reasons, including the determination or belief that the emerging profile of the product candidate is such that it may not receive regulatory approvals in key markets, gain meaningful market acceptance, otherwise provide any competitive advantages in its intended indication or market or generate a significant return to stockholders. Such a delay, suspension or termination could materially harm our business, results of operations or financial condition.

Risks Related to the Discovery, Development, Preclinical and Clinical Testing, Manufacturing and Regulatory Approval of Our Product Candidates

Our business is highly dependent on our ability to identify and develop a bemnifosbuvir COV19 product for the treatment of COVID-19. If we are not successful in identifying and developing a bemnifosbuvir COV19 product candidate, our business will be harmed. Our business is also highly dependent on the success of our other most advanced product candidates, including the combination of bemnifosbuvir and rusazvir for the treatment of HCV, and AT-752 for the treatment of dengue, each of which will require significant additional clinical testing before we can seek regulatory approval and potentially launch commercial sales. If these product candidates fail in clinical development, do not receive regulatory approval or are not successfully commercialized, or are significantly delayed in doing so, our business will be harmed.

A substantial portion of our business and future success depends on our ability to identify and develop a bemnifosbuvir COV19 product candidate for the treatment of COVID-19 and to develop, obtain regulatory approval for and successfully commercialize the combination of bemnifosbuvir and rusazvir for the treatment of HCV and AT-752 for the treatment of dengue. We currently have no products that are approved for commercial sale and have not completed the development of any of our product candidates, and we may never be able to develop marketable products. We expect that a substantial portion of our efforts and expenditures will be devoted to identifying and developing a potential benmnifosbuvir COV19 product candidate for the treatment of COVID-19, which may require additional preclinical and clinical development and expenses related to discovering, acquiring or in-licensing a drug or drug candidate to combine with bemnifosbuvir. Additionally, we expect that a substantial portion of our efforts and expenditures over the next few years will be devoted to developing the combination of bemnifosbuvir and rusazvir for the treatment of HCV and AT-752 for the treatment of dengue, each of which will require additional clinical development, management of clinical, medical affairs and manufacturing activities, obtaining regulatory approvals in multiple jurisdictions, securing of manufacturing supply, building of a commercial organization, substantial investment and significant marketing efforts. We cannot be certain that any of our current or future product candidates will be successful in clinical trials, receive regulatory approval or be successfully commercialized even if we receive regulatory approval. For example, a Phase 2 clinical trial evaluating bemnifosbuvir for the treatment of mild-to-moderate COVID-19 in outpatients failed to meet its primary endpoint in the overall study population. Further, our development of any product candidate may be delayed, which may affect our ability to successfully commercialize such product candidate.

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If our competitors develop products to treat diseases which our current or future product candidates are being developed to treat, before we are able to successfully develop a product candidate, or if our competitors develop any products that are superior to our product candidates, our potential market share could become smaller or non-existent. Even if we receive approval to market any product candidate, we cannot be certain that our product candidates will be as or more effective than other commercially available alternatives, successfully commercialized or widely accepted in the marketplace. Nor can we be certain that, if approved, the safety and efficacy profile of our product candidates will be consistent with the results observed in clinical trials. If we are not successful in the clinical development of our most advanced product candidates or in identifying and developing a bemnifosbuvir COV19 product candidate, the required regulatory approvals for these product candidates are not obtained, there are significant delays in the development or approval of these product candidates, or any approved products are not commercially successful, our business, financial condition and results of operations may be materially harmed.

The regulatory approval processes of the FDA and comparable foreign regulatory authorities are lengthy, expensive, time-consuming, and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for our product candidates, we will be unable to generate product revenue and our business will be seriously harmed.

We are not permitted to commercialize, market, promote or sell any product candidate in the United States without obtaining marketing approval from the FDA. Foreign regulatory authorities impose similar requirements. The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable, typically takes many years following the commencement of clinical trials and depends upon numerous factors, including the type, complexity and novelty of the product candidates involved. In addition, approval policies, regulations or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions, which may cause delays in the approval or the decision not to approve an application.

Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies. We have not submitted an NDA for, or obtained regulatory approval of, any product candidate. We must complete additional preclinical or nonclinical studies and clinical trials to demonstrate the safety and efficacy of our product candidates in humans to the satisfaction of the regulatory authorities before we will be able to obtain these approvals, and it is possible that none of our existing product candidates or any product candidates we may seek to develop in the future will ever obtain regulatory approval. Applications for our product candidates could fail to receive regulatory approval for many reasons, including but not limited to the following:

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This lengthy approval process, as well as the unpredictability of the results of clinical trials, may result in our failing to obtain regulatory approval to market any of our product candidates, which would seriously harm our business. In addition, even if we or our collaborators were to obtain approval, regulatory authorities may approve any of our product candidates for fewer or more limited indications than we request, may impose significant limitations in the form of narrow indications, warnings, or a Risk Evaluation and Mitigation Strategy (“REMS”) or similar risk management measures. Regulatory authorities may not approve the price we or our collaborators intend to charge for products we may develop, may grant approval contingent on the performance of costly post-marketing clinical trials, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate. Any of the foregoing scenarios could seriously harm our business.

Clinical development is lengthy and uncertain. We may encounter substantial delays and costs in our clinical trials, or may not be able to conduct or complete our clinical trials on the timelines we expect, if at all.

Before obtaining marketing approval from the FDA or other comparable foreign regulatory authorities for the sale of our product candidates, we must complete preclinical development and extensive clinical trials to demonstrate the safety and efficacy of our product candidates. Clinical testing is expensive, time-consuming and subject to uncertainty. A failure of one or more clinical trials can occur at any stage of the process, such as the failure in October 2021 of bemnifosbuvir to meet the primary endpoint in the overall patient population in the Phase 2 MOONSONG clinical trial, and the outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials. This is particularly true in the development of therapeutics for the treatment of COVID-19, where the evolution of the virus and disease have occurred at such a rapid rate that product candidates in development have the potential to become obsolete before clinical development is completed. Moreover, preclinical and clinical data, particularly the analysis of exploratory endpoints and analysis of data derived from patient subgroups, are often susceptible to varying interpretations, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their drugs. To date, we have not completed any late-stage or pivotal clinical trials for any of our product candidates. We cannot guarantee that any of our planned or ongoing clinical trials will be initiated or conducted as planned or completed on schedule, if at all. We also cannot be sure that submission of any future IND or similar application will result in the FDA or other regulatory authority, as applicable, allowing future clinical trials to begin in a timely manner, if at all. Moreover, even if these trials begin, issues may arise that could cause regulatory authorities to suspend or terminate such clinical trials. A failure of one or more clinical trials can occur at any stage of testing, and our future clinical trials may not be successful. Events that may prevent successful or timely initiation or completion of clinical trials include but are not limited to:

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In addition, disruptions caused by the COVID-19 pandemic may increase the likelihood that we encounter difficulties or delays in initiating, enrolling, conducting or completing our planned and ongoing clinical trials. In particular, changes in the standard of care for the treatment of COVID-19, which is rapidly evolving due to the mutation of the virus, rapidly increasing knowledge being obtained by healthcare providers, rates and durability of vaccines, and availability of an increasing number of therapeutic options, may impact the initiation or successful completion of clinical trials.

Any inability to successfully initiate or complete clinical trials could result in additional costs to us or impair our ability to generate revenue from product sales. In addition, if we make manufacturing or formulation changes to our product candidates, we may be required to or we may elect to conduct additional studies to bridge our modified product candidates to earlier versions. Clinical trial delays could also shorten any periods during which any approved products have patent protection and may allow our competitors to bring products to market before we do, which could impair our ability to successfully commercialize our product candidates and may seriously harm our business.

We could also encounter delays if a clinical trial is suspended or terminated by us, by the data safety monitoring board (“DSMB”) for such trial, or by the FDA or any other regulatory authority, or if the IRBs of the institutions in which such trials are being conducted suspend or terminate the participation of their clinical investigators and sites subject to their review. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols,

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inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a product candidate, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial.

Further, conducting clinical trials in foreign countries, as we expect to continue doing for our product candidates, presents additional risks that may delay completion of our clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs, managing additional administrative burdens associated with foreign regulatory schemes, as well as political and economic risks relevant to such foreign countries.

Moreover, principal investigators for our clinical trials may serve as scientific advisors or consultants to us from time to time and receive compensation in connection with such services. Under certain circumstances, we may be required to report some of these relationships to the FDA or comparable foreign regulatory authorities. The FDA or comparable foreign regulatory authority may conclude that a financial relationship between us and a principal investigator has created a conflict of interest or otherwise affected interpretation of the study. The FDA or comparable foreign regulatory authority may therefore question the integrity of the data generated at the applicable clinical trial site and the utility of the clinical trial itself may be jeopardized. This could result in a delay in approval, or rejection, of our marketing applications by the FDA or comparable foreign regulatory authority, as the case may be, and may ultimately lead to the denial of marketing approval of one or more of our product candidates.

Delays in the completion of any clinical trial of our product candidates will increase our costs, slow down our product candidate development and approval process and delay or potentially jeopardize our ability to commence product sales and generate product revenue. In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates. Any delays to our clinical trials that occur as a result could shorten any period during which we may have the exclusive right to commercialize our product candidates and our competitors may be able to bring products to market before we do, which could significantly reduce the commercial viability of our product candidates. Any of these occurrences may harm our business, financial condition and prospects significantly.

In addition, the FDA’s and other regulatory authorities’ policies with respect to clinical trials may change and additional government regulations may be enacted. For instance, the regulatory landscape related to clinical trials in the European Union (“EU”) recently evolved. The EU Clinical Trials Regulation (“CTR”) which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. While the Clinical Trials Directive required a separate clinical trial application (“CTA”) to be submitted in each member state, to both the competent national health authority and an independent ethics committee, the CTR introduces a centralized process and only requires the submission of a single application to all member states concerned. The CTR allows sponsors to make a single submission to both the competent authority and an ethics committee in each member state, leading to a single decision per member state. The assessment procedure of the CTA has been harmonized as well, including a joint assessment by all member states concerned, and a separate assessment by each member state with respect to specific requirements related to its own territory, including ethics rules. Each member state’s decision is communicated to the sponsor via the centralized EU portal. Once the CTA is approved, clinical study development may proceed. The CTR foresees a three-year transition period. The extent to which ongoing and new clinical trials will be governed by the CTR varies. For clinical trials whose CTA was made under the Clinical Trials Directive before January 31, 2022, the Clinical Trials Directive will continue to apply on a transitional basis for three years. Additionally, sponsors may still choose to submit a CTA under either the Clinical Trials Directive or the CTR until January 31, 2023 and, if authorized, those will be governed by the Clinical Trials Directive until January 31, 2025. By that date, all ongoing trials will become subject to the provisions of the CTR. Compliance with the CTR requirements by us and our third-party service providers, such as clinical research organizations (“CROs”), may impact our developments plans.

It is currently unclear to what extent the United Kingdom (“UK”) will seek to align its regulations with the EU. The UK regulatory framework in relation to clinical trials is derived from existing EU legislation (as implemented into UK law, through secondary legislation). On January 17, 2022, the UK Medicines and Healthcare products Regulatory Agency (“MHRA”) launched an eight-week consultation on reframing the UK legislation for clinical trials. The consultation closes on March 14, 2022 and aims to streamline clinical trials approvals, enable innovation, enhance clinical trials transparency, enable greater risk proportionality, and promote patient and public involvement in clinical trials. The outcome of the consultation will be closely watched and will determine whether the UK chooses to align with the regulation or diverge from it to maintain regulatory flexibility. A decision by the UK not to closely align its regulations with the new approach that will be adopted in the EU may have an effect on

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the cost of conducting clinical trials in the UK as opposed to other countries and/or make it harder to seek a marketing authorization in the EU for our product candidates on the basis of clinical trials conducted in the UK.

If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials, our development plans may also be impacted.

We intend to develop our product candidates in combination with other therapies, which exposes us to additional risks.

For the treatment of COVID-19, we are evaluating the development of a bemnifosbuvir COV19 product candidate. Even if any product candidate we develop was to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to bear the risks that the FDA or similar foreign regulatory authorities could revoke approval of the therapy used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues could arise with these existing therapies. Combination therapies are commonly used for the treatment of viral infections, and we would be subject to similar risks if we develop any of our product candidates for use in combination with other drugs or biologics or for indications other than COVID-19. Developing combination therapies using approved therapeutics, as we may decide to do for our product candidates, also exposes us to additional clinical risks, such as the requirement that we demonstrate the safety and efficacy of each active component of any combination regimen we may develop.

For the treatment of HCV, we intend to evaluate bemnifosbuvir in combination with ruzasvir, a product candidate that has not yet been approved for marketing by the FDA or similar foreign regulatory authorities. We may not be able to market and sell any product candidate we develop in combination with any such unapproved therapies that do not ultimately obtain marketing approval.

If the FDA or similar foreign regulatory authorities do not approve these other combination agents or revoke their approval of, or if safety, efficacy, manufacturing, or supply issues arise with the drugs or biologics we choose to evaluate in combination with our product candidates, we may be unable to obtain approval of or market our product candidates for combination therapy regimens.

Additionally, if the third-party manufacturers of therapies or therapies in development used in combination with our product candidates are unable to produce sufficient quantities for clinical trials or for commercialization of our product candidates, or if the cost of combination therapies are prohibitive, our development and commercialization efforts would be impaired, which would have an adverse effect on our business, financial condition, results of operations and growth prospects.

Our product candidates may be associated with serious adverse events, undesirable side effects or have other properties that could halt their clinical development, prevent their regulatory approval, limit their commercial potential or result in significant negative consequences.

Adverse events or other undesirable side effects caused by our product candidates could cause us, our collaborators, any DSMB for a trial, or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other comparable foreign regulatory authorities.

During the conduct of clinical trials, patients report changes in their health, including illnesses, injuries, and discomforts, to their study doctor. Often, it is not possible to determine whether or not the product candidate being studied caused these conditions. It is possible that as we test our product candidates in larger, longer and more extensive clinical trials, or as use of these product candidates becomes more widespread if they receive regulatory approval, illnesses, injuries, discomforts and other adverse events that were observed in previous trials, as well as conditions that did not occur or went undetected in previous trials, will be reported by patients. Many times, side effects are only detectable after investigational products are tested in large-scale clinical trials or, in some cases, after they are made available to patients on a commercial scale following approval.

If any serious adverse events occur, clinical trials or commercial distribution of any product candidates or products we develop could be suspended or terminated, and our business could be seriously harmed. Treatment-related side effects could also affect patient recruitment and the ability of enrolled patients to complete the trial or result in potential liability claims. Regulatory authorities could order us to cease further development of, deny approval of, or require us to cease selling any product candidates or products for any or all targeted indications. If we are required to delay, suspend or terminate any clinical trial or commercialization efforts, the commercial prospects of such product candidates or products may be harmed, and our ability to generate product revenues from them or other product candidates that we develop may be delayed or eliminated. Additionally, if one or more of our product candidates receives marketing approval and we or others later identify undesirable side effects or

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adverse events caused by such products, a number of potentially significant negative consequences could result, including but not limited to:

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

If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. The enrollment of patients depends on many factors, including but not limited to:

In addition, our clinical trials will compete with other clinical trials for product candidates that are in the same therapeutic areas as our product candidates or similar areas, and this competition will reduce the number and types of patients available to us because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Since the number of qualified clinical investigators is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which will reduce the number of patients who are available for our clinical trials at such clinical trial sites.

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Delays in patient enrollment may result in increased costs or may affect the timing or outcome of our ongoing and planned clinical trials, which could prevent completion or commencement of these trials and adversely affect our ability to advance the development of our product candidates.

We currently conduct clinical trials, and may in the future choose to conduct additional clinical trials, of our product candidates in sites outside the United States, and the FDA may not accept data from trials conducted in foreign locations.

We currently conduct, and expect in the future to conduct, clinical trials outside the United States for our product candidates. The acceptance of study data from clinical trials conducted outside the U.S. or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. In cases where data from foreign clinical trials are intended to serve as the sole basis for marketing approval in the U.S., the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. In addition, even where the foreign study data are not intended to serve as the sole basis for approval, the FDA will not accept the data as support for an application for marketing approval unless the study is well-designed and well-conducted in accordance with GCP requirements and the FDA is able to validate the data from the study through an onsite inspection if deemed necessary. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the U.S. or the applicable jurisdiction. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in current or future product candidates that we may develop not receiving approval for commercialization in the applicable jurisdiction.

In addition, there are risks inherent in conducting clinical trials in multiple jurisdictions, inside and outside of the United States, such as:

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

From time to time, we may publicly disclose preliminary or top-line data from our preclinical studies and clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. Consequently, the top-line or preliminary data that we report may differ from final results reported from the same studies, or different conclusions or considerations may qualify such preliminary or topline data, once additional data have been received and fully evaluated. Top-line and preliminary data also remain subject to audit and verification procedures that may result in the final results being materially different from the preliminary or topline data we previously published. As a result, top-line data should be viewed with caution until the final data are available.

From time to time, we may also disclose interim data from our preclinical studies and clinical trials. Interim data from clinical trials that we may subsequently complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available or as patients from our clinical trials continue other treatments for their disease. Adverse differences between preliminary or interim data and final results could significantly harm our business prospects. Further, disclosure of interim data by us or by our competitors could result in volatility in the price of our common stock.

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Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general.

In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure. If the interim, top-line, or preliminary data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, our product candidates may be harmed, which could harm our business, operating results, prospects or financial condition.

We may not be successful in our efforts to identify and successfully develop additional product candidates.

Part of our strategy involves identifying novel product candidates. The process by which we identify novel product candidates may fail to yield product candidates for clinical development for a number of reasons, including those discussed in these risk factors and also:

If we are unable to identify and successfully commercialize additional suitable product candidates, this would adversely impact our business strategy and our financial position.

We may focus on potential product candidates that may prove to be unsuccessful and we may have to forego opportunities to develop other product candidates that may prove to be more successful.

We may choose to focus our efforts and resources on a potential product candidate that ultimately proves to be unsuccessful, or to license or purchase a marketed product that does not meet our financial expectations. As a result, we may fail to capitalize on viable commercial products or profitable market opportunities, be required to forego or delay pursuit of opportunities with other product candidates or other diseases that may later prove to have greater commercial potential.

Furthermore, we have limited financial and personnel resources and are placing significant focus on the development of our lead product candidates, particularly bemnifosbuvir COV19 product candidate for the treatment of COVID-19, bemnifosbuvir in combination with rusazvir for the treatment of HCV and AT-752 for the treatment of dengue, and as such, we may forgo or delay pursuit of opportunities with other future product candidates that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and other future product candidates for specific indications may not yield any commercially viable future product candidates. If we do not accurately evaluate the commercial potential or target market for a particular future product candidate, we may relinquish valuable rights to those future product candidates through collaboration, licensing or other royalty arrangements in cases in which it would have been

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more advantageous for us to retain sole development and commercialization rights to such future product candidates.

We may attempt to secure FDA approval of certain product candidates through the use of the accelerated approval pathway or similar expedited approval pathways outside the United States. If we are unable to obtain such approval, we may be required to conduct additional preclinical studies or clinical trials beyond those that we contemplate, which could increase the expense of obtaining, and delay the receipt of, necessary marketing approvals. Even if we receive accelerated approval from the FDA or similar expedited approval by foreign regulatory authorities, if our confirmatory trials do not verify clinical benefit, or if we do not comply with rigorous post-marketing requirements, the FDA or foreign regulatory authorities may seek to withdraw accelerated approval or similar expedited approval.

We are developing certain product candidates for the treatment of serious and life-threatening conditions, and therefore may decide to seek approval of such product candidates under the FDA’s accelerated approval pathway. A product candidate may be eligible for accelerated approval if it is designed to treat a serious or life-threatening disease or condition and generally provides a meaningful advantage over available therapies, upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. The FDA considers a clinical benefit to be a positive therapeutic effect that is clinically meaningful in the context of a given disease, such as irreversible morbidity or mortality. For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign, or other measure that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. An intermediate clinical endpoint is a clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit.

The accelerated approval pathway may be used in cases in which the advantage of a new drug over available therapy may not be a direct therapeutic advantage, but is a clinically important improvement from a patient and public health perspective. If granted, accelerated approval is usually contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug’s clinical benefit. If the sponsor fails to conduct such studies in a timely manner, or if such post-approval studies fail to verify the drug’s predicted clinical benefit, the FDA may withdraw its approval of the drug on an expedited basis.

In the EU, a “conditional” marketing authorization may be granted in cases where all the required safety and efficacy data are not yet available. A conditional marketing authorization is subject to conditions to be fulfilled for generating missing data or ensuring increased safety measures. A conditional marketing authorization is valid for one year and has to be renewed annually until fulfillment of all relevant conditions. Once the applicable pending studies are provided, a conditional marketing authorization can become a “standard” marketing authorization. However, if the conditions are not fulfilled within the timeframe set by the European Medicines Agency (“EMA”), the marketing authorization will cease to be renewed. Furthermore, marketing authorizations may also be granted “under exceptional circumstances” when the applicant can show that it is unable to provide comprehensive data on the efficacy and safety under normal conditions of use even after the product has been authorized and subject to the introduction of specific procedures. This may arise when the intended indications are very rare and, in the present state of scientific knowledge, it is not possible to provide comprehensive information, or when generating data may be contrary to generally accepted ethical principles. This type of marketing authorization is close to a conditional marketing authorization as it is reserved to medicinal products to be approved for severe diseases or unmet medical needs and the applicant does not hold the complete data set legally required for the grant of a marketing authorization. However, unlike a conditional marketing authorization, the applicant does not have to provide the missing data and will never have to. Although a marketing authorization “under exceptional circumstances” is granted definitively, the risk-benefit balance of the medicinal product is reviewed annually and the marketing authorization may be withdrawn where the risk-benefit ratio is no longer favorable. If we decide to submit an NDA seeking accelerated approval or receive an expedited regulatory designation for our product candidates, there can be no assurance that such submission or application will be accepted or that any expedited development, review or approval will be granted on a timely basis, or at all. Failure to obtain accelerated approval or any other form of expedited development, review or approval for a product candidate would result in a longer time period to commercialization of such product candidate, if any, and could increase the cost of development of such product candidate, which could harm our competitive position in the marketplace.

Even if we complete the necessary preclinical studies and clinical trials, the marketing approval process is expensive, time-consuming and uncertain and may prevent us or any future collaboration partners from obtaining approvals for the commercialization of any product candidate we develop.

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Any product candidates we may develop and the activities associated with their development and commercialization, including their design, testing, manufacture, safety, efficacy, recordkeeping, labeling, storage, approval, advertising, promotion, sale and distribution, are subject to comprehensive regulation by the FDA and other regulatory authorities in the United States and by comparable authorities in other countries. Any product candidates we develop may not be effective, may be only moderately effective, or 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. Failure to obtain marketing approval for a product candidate will prevent us from commercializing the product candidate in a given jurisdiction. Our development programs are early-stage and we have not received approval to market any product candidates from regulatory authorities in any jurisdiction. It is possible that none of the product candidates we are developing or that we may seek to develop in the future will ever obtain regulatory approval. We have no experience in filing and supporting the applications necessary to gain marketing approvals and expect to rely on third-party CROs, suppliers, vendors or regulatory consultants to assist us in this process. Securing regulatory approval requires the submission of extensive preclinical and clinical data and supporting information to the various regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing regulatory approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities by, the relevant regulatory authority.

The process of obtaining marketing approvals, both in the United States and abroad, is expensive, may take many years if numerous clinical trials are required, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Changes in marketing approval policies during the development period, changes in or the enactment of additional statutes or regulations, or changes in regulatory review for each submitted product application, may cause delays in the approval or rejection of an application. For instance, the EU pharmaceutical legislation is currently undergoing a complete review process, in the context of the Pharmaceutical Strategy for Europe initiative, launched by the European Commission in November 2020. A proposal for revision of several legislative instruments related to medicinal products (potentially revising the duration of regulatory exclusivity, eligibility for expedited pathways, etc.) is expected to be adopted by the European Commission by the end of 2022. The proposed revisions, once they are agreed and adopted by the European Parliament and European Council (not expected before the end of 2024) may have a significant impact on the pharmaceutical industry in the long term.

The FDA and comparable authorities in other countries have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent marketing approval of a product candidate. Any marketing approval we ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable.

If we experience delays in obtaining approval or if we fail to obtain approval of any product candidates we may develop, the commercial prospects for those product candidates may be harmed, and our ability to generate product revenue will be materially impaired.

We may seek an EUA from the FDA or comparable emergency use authorizations from foreign regulatory authorities with respect to our product candidate in development for the treatment of COVID-19, and if we fail to obtain or maintain such authorizations, we may be required to pursue a more lengthy clinical development process than we expect, and our business may be harmed.

We may seek an EUA from the FDA or comparable emergency use authorizations from other foreign regulatory authorities with respect to our COVID-19 product candidate. The FDA has the authority to issue an EUA under certain circumstances, such as during a public health emergency, pursuant to a declaration by the Secretary of the Department of Health and Human Services, or HHS, that an emergency exists justifying the issuance of EUAs for certain types of products (referred to as EUA declarations). On March 27, 2020, the Secretary of HHS declared that circumstances exist justifying authorization of drugs and biologics during the COVID-19 pandemic, subject to the terms of any EUA that is issued for a specific product. Once an EUA declaration has been issued and remains in place, the FDA can issue EUAs for products that fall within the scope of that declaration. To issue an EUA, the FDA Commissioner must conclude that (1) the chemical, biological, radioactive or nuclear agent, or CBRN, that is referred to in the EUA declaration can cause serious or life-threatening diseases or conditions; (2) based on the totality of scientific evidence available, it is reasonable to believe that the product may be effective in diagnosing, treating, or preventing the disease or condition attributable to the CBRN and that the product’s known and potential benefits outweigh its known and potential risks; and (3) there is no adequate, approved, and available alternative to the product.

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The FDA’s standards for granting an EUA are lower than for approving NDAs in accordance with traditional review procedures, and even if we seek and obtain an EUA for one or more of our product candidates, we cannot assure you that the FDA would approve a NDA for such product candidate, if such approval is required. Accordingly, even if we obtain an EUA for one or more of our product candidates, we may be required to conduct additional clinical trials before we are able to submit NDAs or comparable marketing applications for such product candidates.

In addition, the authorization to market products under an EUA is limited to the period of time the EUA declaration is in effect, and the FDA can revoke an EUA in certain circumstances. The FDA’s policies regarding an EUA can change unexpectedly. We cannot predict how long any authorization, if obtained, will remain in place. The FDA’s policies regarding vaccines and other products used to diagnose, treat or mitigate COVID-19 remain in flux as the FDA responds to new and evolving public health information and clinical evidence.

Therefore, even if we obtain an EUA or other emergency authorizations for one or more of our product candidates, it is possible that such EUA or other authorizations may be revoked and we may be required to cease any commercialization activities, which would adversely impact our business, financial condition and results of operations.

Even if we obtain FDA approval of any of our product candidates, we may never obtain approval or commercialize such products outside of the United States, which would limit our ability to realize their full market potential.

In order to market any products outside of the United States, we must establish and comply with numerous and varying regulatory requirements of other countries regarding safety and efficacy. Clinical trials conducted in one country may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not mean that regulatory approval will be obtained in any other country. Approval procedures vary among countries and can involve additional product testing and validation and additional administrative review periods. Seeking foreign regulatory approvals could result in significant delays, difficulties and costs for us and may require additional preclinical studies or clinical trials which would be costly and time-consuming. Regulatory requirements can vary widely from country to country and could delay or prevent the introduction of our products in those countries. Satisfying these and other regulatory requirements is costly, time-consuming, uncertain and subject to unanticipated delays. In addition, our failure to obtain regulatory approval in any country may delay or have negative effects on the process for regulatory approval in other countries. We do not have any product candidates approved for sale in any jurisdiction, including international markets, and we do not have experience in obtaining regulatory approval in international markets. If we fail to comply with regulatory requirements in international markets or to obtain and maintain required approvals, our ability to realize the full market potential of our products will be harmed.

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

If any current or future product candidate we develop receives marketing approval, whether as a single agent or in combination with other therapies, it may nonetheless fail to gain sufficient market acceptance by physicians, patients, third-party payors and others in the medical community. For example, current approved antiviral products are well established in the medical community for the treatment of HCV and oral antivirals have been recently authorized for the treatment of COVID-19, and doctors may continue to rely on these therapies. If the product candidates we develop do not achieve an adequate level of acceptance, we may not generate significant product revenues and we may not become profitable. The degree of market acceptance of any product candidate, if approved for commercial sale, will depend on a number of factors, including but not limited to:

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Disruptions at the FDA and foreign regulatory authorities caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved or commercialized in a timely manner or at all, which could negatively impact our business.

The ability of the FDA and foreign regulatory authorities to review or approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory, and policy changes, the FDA’s or foreign regulatory authorities’ ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s or foreign regulatory authorities’ ability to perform routine functions including a rapid substantial influx of applications from numerous sponsors as occurred with COVID-19. Average review times at the FDA and foreign regulatory authorities have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA and other agencies, such as the EMA following its relocation to Amsterdam and resulting staff changes, may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities.

Separately, in response to the COVID-19 pandemic, in March 2020, the FDA announced its intention to postpone most inspections of foreign manufacturing facilities, and on March 18, 2020, the FDA temporarily postponed routine surveillance inspections of domestic manufacturing facilities. Subsequently, in July 2020, the FDA resumed certain on-site inspections of domestic manufacturing facilities subject to a risk-based prioritization system. The FDA utilized this risk-based assessment system to assist in determining when and where it was safest to conduct prioritized domestic inspections. Additionally, on April 15, 2021, the FDA issued a guidance document in which the FDA described its plans to conduct voluntary remote interactive evaluations of certain drug manufacturing facilities and clinical research sites, among other facilities. According to the guidance, the FDA may request such remote interactive evaluations where the FDA determines that remote evaluation would be appropriate based on mission needs and travel limitations. In May 2021, the FDA outlined a detailed plan to move toward a more consistent state of inspectional operations, and in July 2021, the FDA resumed standard inspectional operations of domestic facilities and was continuing to maintain this level of operation as of May 2022. More recently, the FDA has continued to monitor and implement changes to its inspectional activities to ensure the safety of its employees and those of the firms it regulates as it adapts to the evolving COVID-19 pandemic. Regulatory authorities outside the United States have adopted similar restrictions or other policy measures in response to the COVID-19 pandemic. If a prolonged government shutdown occurs, or if global health concerns continue to prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, it could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business.

Our insurance policies are expensive and protect us only from some business risks, which leaves us exposed to significant uninsured liabilities.

Though we have insurance coverage for clinical trial product liability, we do not carry insurance for all categories of risk that our business may encounter. Some of the policies we currently maintain include general liability, property, auto, workers’ compensation, umbrella, and directors’ and officers’ insurance.

Any additional product liability insurance coverage we acquire in the future may not be sufficient to reimburse us for any expenses or losses we may suffer. Moreover, insurance coverage is becoming increasingly expensive and in the future we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses due to liability. If we obtain marketing approval for any of our product candidates, we intend to acquire insurance coverage to include the sale of commercial products; however, we may be unable to obtain product liability insurance on commercially reasonable terms or in adequate amounts. A successful product liability claim or series of claims brought against us could cause our stock price to decline and, if judgments exceed our insurance coverage, could adversely affect our results of operations and business, including preventing or limiting the development and commercialization of any product candidates we develop. We do not carry specific biological or hazardous waste insurance coverage, and our property, casualty and general liability insurance policies specifically exclude coverage for damages and fines arising from biological or hazardous waste

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exposure or contamination. Accordingly, in the event of contamination or injury, we could be held liable for damages or be penalized with fines in an amount exceeding our resources, and our clinical trials or regulatory approvals could be suspended.

Operating as a public company has and will make it more difficult and more expensive for us to obtain director and officer liability insurance, and we may be required to accept reduced policy limits and coverage or incur substantially higher costs to obtain the same or similar coverage. As a result, it may be more difficult for us to attract and retain qualified people to serve on our board of directors, our board committees or as executive officers. We do not know, however, if we will be able to maintain existing insurance with adequate levels of coverage. Any significant uninsured liability may require us to pay substantial amounts, which would adversely affect our cash and cash equivalents position and results of operations.