Proxy Statement (Form DEF 14A)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.)

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

ATEA PHARMACEUTICALS, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

You are cordially invited to attend the 2026 Annual Meeting of Stockholders (the "Annual Meeting") of Atea Pharmaceuticals, Inc., a Delaware corporation ("Atea," the "Company," "we," "our" or "us").

These items of business are more fully described in the Proxy Statement accompanying this Notice of Annual Meeting. We will also consider and transact any other business that may properly come before the Annual Meeting or any continuation, postponement, or adjournment of the Annual Meeting. If any other matter properly comes before the stockholders for a vote at the Annual Meeting, the proxy holders named on the Company's proxy card will vote your shares in accordance with their best judgment.

WHO CAN VOTE AND PARTICIPATE

Holders of record of Atea common stock as of the close of business on April 24, 2026, the record date fixed by the Board of Directors (the "Board"), are entitled to notice of, and to vote at, the Annual Meeting, and at any continuations, adjournments or postponements thereof. A complete list of such stockholders will be open to the examination of any stockholder for a period of ten days prior to the Annual Meeting for a purpose germane to the Annual Meeting by sending an email to [email protected] stating the purpose of the request and providing proof of ownership of Atea common stock. The Annual Meeting may be continued or adjourned from time to time without notice other than by announcement at the Annual Meeting.

HOW TO PARTICIPATE IN THE VIRTUAL ANNUAL MEETING

To participate in the virtual Annual Meeting, visit http://www.virtualshareholdermeeting.com/AVIR2026 and enter the 16-digit control number on your proxy card or on the instructions that accompanied your proxy materials.

HOW TO VOTE

Further information and instructions regarding the Annual Meeting, the voting process, the quorum and the required votes for the approval of each of the proposals can be found in the "Questions & Answers About The 2026 Annual Meeting Of Stockholders" section starting on page 66. Whether or not you plan to attend the Annual Meeting, it is important to read the Proxy Statement in its entirety and then cast your vote as promptly as possible.

YOUR VOTE IS IMPORTANT

Even if you plan to attend the Annual Meeting, we urge you to vote your shares as promptly as possible to ensure your representation and the presence of a quorum at the Annual Meeting. If you choose to attend the Annual Meeting, you may vote your shares electronically, even if you have previously voted or returned your proxy by any of the methods described in the Proxy Statement.

By Order of the Board of Directors,

Andrea Corcoran

Chief Financial Officer, Executive Vice President, Legal and Secretary

Boston, Massachusetts

April 27, 2026

April 27, 2026

On behalf of the Board of Directors of Atea Pharmaceuticals ("Atea" or the "Company"), we are pleased to invite you to attend Atea's 2026 Annual Meeting of Stockholders ("Annual Meeting"). More details on the Annual Meeting can be found in the enclosed notice and proxy materials.

In 2025, Atea advanced its strategic priorities executing across our antiviral drug discovery and development programs and corporate initiatives. Throughout the year, our focus on operational execution was matched with continued discipline in the allocation of resources, all with the objective of delivering long-term value for our stockholders.

Our clinical team significantly advanced the Phase 3 clinical development of the regimen of bemnifosbuvir and ruzasvir for the treatment of chronic hepatitis C virus ("HCV"). Topline results from the Phase 3 C-BEYOND trial are expected mid-2026 with results from the Phase 3 C-FORWARD trial anticipated by year end 2026. HCV remains a significant global health burden with as many as 4 million individuals estimated to be infected with HCV in the United States. Driven by continual high rates of infection that outpace the rates of treatment, the commercial market for HCV therapeutics is expected to remain substantial for the foreseeable future with ongoing need for effective and convenient oral antiviral therapies. In 2025, global net sales of HCV therapeutics approximated $2.5 billion.

Results from our Phase 2 trial demonstrated a 98% sustained virologic response at 12 weeks post-treatment among per-protocol, treatment-adherent patients following eight weeks of therapy. The regimen was generally well tolerated with no drug-related serious adverse events or treatment discontinuations. These Phase 2 results, together with results from other preclinical and clinical studies, support a differentiated, potentially best-in-class profile for the bemnifosbuvir and ruzasvir fixed dose combination. In an HCV commercial market which is evolving with the increasing adoption of the test-and-treat model of care, we believe that the short duration, lack of drug-drug interactions and convenience of administration with or without food positions our regimen well and has the potential to support, after approval, rapid attainment of competitive market share.

Additionally, we broadened our antiviral pipeline with the introduction of AT-587, a new product candidate we are developing for the treatment of hepatitis E virus (HEV), an emerging public health concern for immunocompromised and other high-risk patient populations with no approved therapies. We anticipate initiating a Phase 1 program mid-year 2026.

In early 2025, we implemented a workforce reduction of approximately 25%, a strategic action that is projected to generate approximately $15 million in cost savings through 2027. We also completed a $25 million stock repurchase program, retiring and returning 7,673,792 shares of stock to authorized but unissued status, underscoring our commitment to return capital to stockholders while maintaining the flexibility needed to position Atea for long-term success.

The enclosed 2026 Proxy Statement includes important information regarding the matters to be voted on at the Annual Meeting, including director elections, ratification of our independent registered public accounting firm, and the approval on an advisory (non-binding) basis of the compensation of our named executive officers. Your vote is important, and we encourage you to participate-either by attending the virtual meeting or voting by proxy.

Thank you for your continued trust, engagement, and support.

Jean-Pierre Sommadossi, PhD

Chairman of the Board of Directors

Chief Executive Officer

TABLE OF CONTENTS

Forward-Looking Statements

This Proxy Statement includes "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements in this Proxy Statement include but are not limited to statements regarding the potential best-in-class profile and market opportunity of the bemnifosbuvir and ruzasvir regimen for the treatment of hepatitis C virus ("HCV"), the potential opportunity to advance efforts to eradicate HCV, the potential to develop a product for the treatment of hepatitis E virus ("HEV"), anticipated milestone events and timelines for clinical trials including the timeline for readout of the HCV Phase 3 clinical trials results and initiation of the HEV clinical development, future results of operations and business strategy. When used herein, words including "expected," "should," "anticipated," "believe," "will," "plans", and similar expressions are intended to identify forward-looking statements. In addition, any statements or information that refer to expectations, beliefs, plans, projections, objectives, performance or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking. All forward-looking statements are based upon our current expectations and various assumptions. We believe there is a reasonable basis for our expectations and beliefs, but they are inherently uncertain. We may not realize our expectations, and our beliefs may not prove correct. Actual results could differ materially from those described or implied by such forward-looking statements as a result of various important factors, including, without limitation, uncertainties inherent in the drug discovery and development process and the regulatory submission or approval process, unexpected or unfavorable safety or efficacy data or results observed during clinical trials or in data readouts; delays in or disruptions to clinical trials or our business; our reliance on third parties over which we may not always have full control; our ability to manufacture sufficient commercial product; competition from approved treatments for HCV; dependence on the success of our most advanced product candidates, in particular the bemnifosbuvir and ruzasvir regimen for the treatment of HCV; as well as the other important factors discussed under the caption "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2025 as such factors may be updated from time to time in our other filings with the U.S. Securities and Exchange Commission ("SEC"), which are accessible on the SEC's website at www.sec.gov. These and other important factors could cause actual results to differ materially from those indicated by the forward-looking statements made in this Proxy Statement. Any such forward-looking statements represent management's estimates as of the date of this Proxy Statement. While we may elect to update such forward-looking statements at some point in the future, except as required by law, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this Proxy Statement.

ATEA PHARMACEUTICALS, INC.

225 FRANKLIN STREET, SUITE 2100

BOSTON, MASSACHUSETTS 02110

PROXY STATEMENT

This Proxy Statement is furnished in connection with the solicitation by the Board of Directors ("Board") of Atea Pharmaceuticals, Inc. of proxies to be voted at our Annual Meeting of Stockholders to be held virtually via live webcast on Friday, June 18, 2026 ("Annual Meeting"), beginning at 9:00 a.m. Eastern time, and at any continuation, postponement, or adjournment of the Annual Meeting.

Holders of record of shares of our common stock, $0.001 par value per share ("Common Stock"), as of the close of business on April 24, 2026 ("Record Date"), will be entitled to notice of and to vote at the Annual Meeting and any continuation, postponement, or adjournment of the Annual Meeting. As of April 24, 2026, there were 80,027,099 shares of Common Stock outstanding. Each share of Common Stock is entitled to one vote on any matter presented to stockholders at the Annual Meeting. This Proxy Statement and our Annual Report on Form 10-K for the year ended December 31, 2025 are expected to be released on or about May 4, 2026 to our stockholders as of the Record Date.

In this Proxy Statement, "Atea", "Company", "we", "us", and "our" all refer to Atea Pharmaceuticals, Inc.

Attending the Meeting

You may attend the Annual Meeting and submit your questions and vote electronically during the Annual Meeting by visiting www.virtualshareholdermeeting.com/AVIR2026 and entering the 16-digit control number included on your proxy card or on the instructions that accompanied your proxy materials.

Proposals

At the Annual Meeting, our stockholders will be asked:

Recommendations of the Board

The Board recommends that you vote your shares as indicated below. If you return a properly completed proxy card or vote your shares by telephone or Internet, your shares will be voted on your behalf as you direct. You may also vote your shares electronically during the Annual Meeting. If not otherwise specified, the shares of Common Stock represented by the proxies will be voted, and the Board recommends that you vote:

If any other matter properly comes before the stockholders for a vote at the Annual Meeting, the proxy holders named on the Company's proxy card will vote your shares in accordance with their best judgment.

Information About This Proxy Statement

Why you received this Proxy Statement. You are viewing or have received these proxy materials because Atea's Board is soliciting your proxy to vote your shares at the Annual Meeting. This Proxy Statement includes information that we are required to provide to you under the rules of the U.S. Securities and Exchange Commission ("SEC") and that is designed to assist you in voting your shares.

Printed Copies of Our Proxy Materials. If you received printed copies of our proxy materials, then instructions regarding how you can vote are contained on the proxy card included in the materials.

2

We are a late-stage clinical biopharmaceutical company with deep expertise in antiviral drug development, advancing a pipeline focused on areas of significant unmet medical need. Our lead program-a combination regimen of bemnifosbuvir and ruzasvir for the treatment of chronic hepatitis C virus (HCV)-progressed into Phase 3 development in 2025, supported by robust Phase 2 results which demonstrated a 98% sustained virologic response rate among treatment-adherent patients. Results to-date support our regimen as a potential best-in-class HCV treatment option with a differentiated profile. In clinical trials, the regimen has demonstrated efficacy and tolerability, low risk of drug-drug interactions and convenient dosing with no food effect.

In 2025, we expanded our antiviral portfolio with the addition of AT-587, a novel product candidate for the treatment of hepatitis E virus (HEV). With heightened impact on immunocompromised and other high-risk populations, HEV is an emerging global public health concern for which there are no currently approved therapies. For immunocompromised patients living with chronic HEV infection there is a major unmet medical need for an approved treatment. In these patients, chronic HEV can rapidly progress to cirrhosis within three to five years if left untreated.

The HCV and HEV commercial market opportunities are substantial and are anticipated to remain that way for the foreseeable future. In 2025, global net sales of currently approved HCV antiviral therapies exceeded $2.5 billion with the US accounting for approximately 50% of these sales. For HEV, we estimate that treatment of immunocompromised patients with a direct acting antiviral represents a significant market opportunity.

3

Our Board includes high-quality and accomplished directors who contribute complementary skills, experience, backgrounds and perspectives that facilitate robust oversight of management and the Company.

With more than half of our independent directors appointed since 2020, including two independent directors newly appointed in 2025, the Board has been significantly refreshed welcoming new perspectives while retaining the institutional knowledge possessed by our directors with longer tenure.

Our Board is focused on ensuring the execution of our strategy, enhancing performance and creating an environment that increases operational efficiency - all of which will contribute to Atea's long-term growth and the creation of sustainable stockholder value.

4

The governance structure adopted at the time of Atea's initial public offering ("IPO") in 2020 reflects the Board's intentions to allow leadership to drive the creation of long-term stockholder value by focusing, in a financially disciplined manner, on the discovery and development of first- or best-in-class oral antiviral therapeutics.

5

Our Compensation Committee designs incentives based on Company performance that both emphasize the creation of sustainable long-term stockholder value and attract, motivate and retain highly qualified and experienced executives.

The design of our executive compensation program promotes performance alignment and protects stockholder interests.

For 2025, the resulting Target Pay mix was:

6

The Board is committed to maintaining regular, meaningful engagement with our stockholders to better understand their perspectives. The Board values stockholder feedback received as it serves as a key input to Board and Board committee discussions and ultimately informs decision-making. Since our 2020 IPO, we have regularly engaged constructively and proactively with stockholders to understand their views on matters of strategy, corporate governance, executive compensation, capital allocation, and overall performance.

During 2025, we conducted a robust and comprehensive outreach effort, engaging both existing and potential stockholders through a broad range of meetings and interactions designed to communicate our strategy, governance practices, and long-term priorities, while also soliciting investor feedback. Following the 2025 Annual Meeting, we offered engagement opportunities to stockholders representing more than 50% of our outstanding shares of common stock. Stockholders with whom we engaged-representing the majority of responding share ownership-generally focused discussions on our strategic direction, operational execution, capital stewardship, and governance practices.

These meetings with stockholders included members of our senior management team. Feedback received through this outreach was communicated directly to the full Board and to relevant Board committees and was a meaningful input into Board deliberations, including governance and compensation-related decisions. The Board values this ongoing dialogue and views stockholder engagement as an integral component of effective corporate governance and long-term stockholder value creation.

7

Under our Restated Certificate of Incorporation, our Board is divided into three classes, with each class having as nearly as possible an equal number of directors and the three classes having staggered terms. At each annual meeting of the stockholders, one class of directors is elected for a three-year term to succeed the directors of the same class whose term is then expiring.

Our Board has fixed the number of directors at nine as of the date of this Proxy Statement. The current class structure is as follows: Class I, whose term will expire at the 2027 annual meeting of stockholders; Class II, whose term will expire at the 2028 annual meeting of stockholders; and Class III, whose current term will expire at the Annual Meeting and, if elected at the Annual Meeting, whose subsequent term will expire at the 2029 annual meeting of stockholders. The current Class I directors are Franklin Berger, Arthur Kirsch and Jean-Pierre Sommadossi, PhD; the current Class II directors are Bruno Lucidi, Polly Murphy, DVM, PhD and Bruce Polsky, MD, MACP, FIDSA; and the current Class III directors are Jerome Adams, MD, MPH, Howard Berman, PhD, and Barbara Duncan.

The Board has unanimously nominated each of Dr. Adams, Dr. Berman and Ms. Duncan for re-election as Class III Directors at the Annual Meeting. If re-elected, Dr. Adams, Dr. Berman and Ms. Duncan will hold office until the 2029 annual meeting of stockholders and until each of such director's respective successor is elected and qualified or until each of such director's earlier death, resignation or removal.

Each nominee has consented to being named in this Proxy Statement and to serve, if elected. If any nominee is unable to serve or for good cause will not serve as a director, it is intended that the proxies will be voted for any substitute nominee designated by the Board or the Board may elect to reduce its size. The Board has no reason to believe that the nominees named below will be unable to serve if elected.

Recommendation of the Board

8

The following table outlines the directors who currently serve on our Board along with their respective years of appointment and key Board committee roles. The directors in the shaded rows have been nominated by our Board for election by stockholders at the Annual Meeting.

The biographies of our directors starting on the next page outline their principal occupations and business experience and how each individual contributes to Board oversight:

9

10

11

12

13

14

15

16

17

18

General

Our Board believes that good corporate governance promotes the long-term interests of our stockholders and strengthens the accountability of our Board and management. As a part of its commitment to good corporate governance, our Board has adopted Corporate Governance Guidelines, a Code of Business Conduct and Ethics, and charters for each of our Audit Committee, Compensation Committee, Nominating and Corporate Governance Committee and Strategy and Public Policy Committee to assist the Board in the exercise of its responsibilities and to serve as a framework for the effective governance of the Company. These documents are accessible in the "Investors-Corporate Governance-Documents and Charters" section of our website located at www.ateapharma.com. Copies of each of these documents may also be obtained by writing to our Secretary at our offices at 225 Franklin Street, Suite 2100, Boston, Massachusetts 02110.

Board Composition

Our Board currently consists of nine members: Jerome Adams, MD, MPH, Franklin Berger, Howard Berman, PhD, Barbara Duncan, Arthur Kirsch, Bruno Lucidi, Polly A. Murphy, DVM, PhD, Bruce Polsky, MD, MACP, FIDSA, and Jean-Pierre Sommadossi, PhD.

Board Refreshment

We have a highly engaged Board with directors providing the relevant expertise, skills and experiences essential to overseeing the company's business needs and overall strategy. Our Board includes members with deep knowledge in science and medicine, as well as those with significant experience in business leadership, commercialization of antiviral therapeutics, business development, strategic transactions, finance and public policy.

From 2020 to 2025, we added five new directors to our Board: Barbara Duncan and Polly Murphy, DVM, PhD, in 2020, Jerome Adams, MD, MPH, in 2021 and Arthur Kirsch and Howard Berman, PhD, in 2025.

Classified Board and Staggered Terms

As set forth in our Restated Certificate of Incorporation, the Board is currently divided into three classes with staggered, three-year terms. At each annual meeting of stockholders, the successors to directors whose terms then expire will be elected to serve from the time of election and qualification until the third annual meeting following election. Our Restated Certificate of Incorporation and bylaws provide that the authorized number of directors may be changed only by resolution of the Board. Any additional directorships resulting from an increase in the number of directors will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the directors. Such additional directorships or any vacancies on the Board may be filled only by the affirmative vote of a majority of remaining directors then in office even if less than a majority. The division of our Board into three classes with staggered three-year terms may delay or prevent a change of our management or a change in control of our Company. Our directors may be removed only for cause by the affirmative vote of the holders of at least two-thirds in voting power of the outstanding shares of our capital stock entitled to vote in the election of directors.

19

The time horizon required for successful development of antiviral therapeutics makes it vital that we have a board that understands the implications of this process and has the ability to develop and implement long-term strategies while benefiting from an in-depth knowledge of our business and operations. We believe that our classified board structure aligns with this long-term orientation and has enabled our Board to provide educated and sophisticated oversight of management. Our Board and Nominating and Corporate Governance Committee routinely evaluate the appropriateness of a classified board and continue to believe that such a board structure aligns with the Company's long-term orientation and enables the Board to provide appropriate and expert oversight of management over the course of the multi-year life cycles of our clinical development programs, which our Board believes ultimately drives the creation of sustainable stockholder value. In addition, the Board believes three-year terms enhance the independence of our non-employee directors by providing continuity of service and protecting them against potential pressures from special interest groups or others who might have agendas contrary to the long-term interests of our stockholders.

Director Independence

Our Board has affirmatively determined that each of Jerome Adams, MD, MPH, Franklin Berger, Howard Berman, PhD, Barbara Duncan, Arthur Kirsch, Bruno Lucidi, Polly A. Murphy, DVM, PhD, and Bruce Polsky, MD, MACP, FIDSA, qualifies as "independent" in accordance with the listing requirements of Nasdaq. The Nasdaq independence definition includes a series of objective tests, including that the director is not, and has not been at any time in the last three years, one of our employees and that neither the director nor any of his or her family members has engaged in various types of business dealings with us. In addition, as required by Nasdaq rules, our Board has made a subjective determination as to each independent director that no relationships exist, which, in the opinion of our Board, would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In making these determinations, our Board reviewed information provided by the directors and us with regard to each director's business and personal activities and relationships as they may relate to us and our management. Jean-Pierre Sommadossi, PhD, our CEO, is not independent.

There are no family relationships among any of our directors or executive officers.

Board Meetings and Attendance

Our Board met five times during the year ended December 31, 2025 and each director who served on the Board during 2025 attended at least 75% of the aggregate of (i) all meetings of the Board and (ii) all meetings of the committees on which the director served.

We encourage all our directors to attend our annual meetings of stockholders. All eight members of our Board at the time of the 2025 annual meeting of stockholders attended the meeting.

In the matrix below, we detail the significant experience and skills of each of our director nominees and our other directors that we think are especially relevant to his or her service on our Board.

20

Board Experience and Diversity Matrix

Our Board is comprised of directors with comprehensive and complementary skills and experience, enabling effective oversight and strategic guidance to drive growth and enhance stockholder value at a biopharmaceutical company advancing an antiviral product candidate in late-stage clinical development toward commercialization while also engaging in innovative antiviral discovery and development activities. The following chart summarizes the core skills of each our directors. Directors in the green columns are nominated by our Board for election by stockholders at the Annual Meeting.

Director Candidates

The Nominating and Corporate Governance Committee is responsible for searching for identifying and reviewing the qualifications of potential director candidates and recommending to the Board those candidates.

21

To facilitate the search process, the Nominating and Corporate Governance Committee may solicit our current directors and executives for the names of potentially qualified candidates or ask our directors and executives to pursue their own business contacts for the names of potentially qualified candidates. The Nominating and Corporate Governance Committee may also consult with outside advisors or retain search firms to assist in the search for qualified candidates, or consider director candidates recommended by our stockholders. Dr. Berman was initially recommended as a director candidate by a stockholder of the Company.

Once potential candidates are identified, the Nominating and Corporate Governance Committee reviews the backgrounds of those candidates, evaluates the candidates' independence from the Company and any potential conflicts of interest and determines if the candidates meet the qualifications desired by the Nominating and Corporate Governance Committee for candidates for election as a director.

In evaluating the suitability of individual candidates (both new candidates and current Board members), the Nominating and Corporate Governance Committee, in recommending candidates for election, and the Board, in approving (and, in the case of vacancies, appointing) such candidates, may take into account many factors, including: personal and professional integrity, ethics and values; experience in corporate management, such as serving as an officer or former officer of a publicly held company; strong finance experience; relevant social policy concerns; experience relevant to the Company's industry; experience as a board member of another publicly held company; relevant academic expertise or other proficiency in an area of the Company's operations; diversity of expertise and experience in substantive matters pertaining to the Company's business relative to other Board members; diversity of background and perspective; practical and mature business judgment, including, but not limited to, the ability to make independent analytical inquiries; and any other relevant qualifications, attributes or skills. The Board evaluates each individual in the context of the Board as a whole, with the objective of assembling a group that can further the Company's success and represent stockholder interests through the exercise of sound judgment using its diversity of experience in these various areas. In determining whether to recommend a director for re-election, the Nominating and Corporate Governance Committee may also consider the director's past attendance at meetings and participation in and contributions to the activities of the Board.

Stockholder Recommendations for Director Candidates

Stockholders may recommend individuals to the Nominating and Corporate Governance Committee for consideration as potential director candidates by submitting the names of the recommended individuals, together with appropriate biographical information and background materials, to the Nominating and Corporate Governance Committee, c/o Secretary, Atea Pharmaceuticals, Inc., 225 Franklin Street, Suite 2100, Boston, Massachusetts 02110. In the event there is a vacancy, and assuming that appropriate biographical and background materials have been provided on a timely basis, the Nominating and Corporate Governance Committee will evaluate stockholder recommended candidates by following substantially the same process, and applying substantially the same criteria, as it follows for candidates submitted by others.

Stockholder Engagement and Communications

Our Board and management team value the views of our stockholders. Consistent with our commitment to enabling open and ongoing dialogue with stockholders, we actively engage and meet with stockholders throughout the year and discuss a variety of topics, including our research and development activities, commercialization plans, business strategy, financial outlook, and corporate governance matters.

During 2025, we conducted a robust and comprehensive outreach effort, engaging both existing and potential stockholders through a broad range of meetings and interactions designed to communicate our strategy, governance practices, and long-term priorities, while also soliciting investor feedback. Following the 2025 Annual Meeting, we offered engagement opportunities to stockholders representing more than 50% of our outstanding shares of common stock. Stockholders with whom we engaged-representing the majority of responding share ownership-generally focused discussions on our strategic direction, operational execution, capital stewardship, and governance practices.

22

In addition to individual meetings with stockholders, members of our management team participate in non-deal roadshows and healthcare investment banking conferences, which include Company presentations and fireside chats. The Company also regularly hosts quarterly financial and business updates which include question and answer sessions. Replays of the most recent of these events are accessible in the "Investors" section of our website located at www.ateapharma.com. We believe this active engagement enables us to better understand the perspectives of our stockholders and enables feedback channels that provide a valuable way to receive ongoing input from our stockholders and potential investors.

Any stockholder who would like to communicate with, or otherwise make his or her concerns known directly to the Board, the chairperson of any of the Audit, Compensation, Nominating and Corporate Governance and Strategy and Public Policy Committee or to the non-management directors as a group or any individual director, may do so by addressing such communications or concerns to the Secretary, Atea Pharmaceuticals, Inc., 225 Franklin Street, Suite 2100, Boston, Massachusetts 02110 who will provide such communications to the appropriate party. Such communications may be done confidentially or anonymously.

Corporate Governance Guidelines

The Board has adopted Corporate Governance Guidelines to ensure that the Board will have the necessary authority and practices in place to review and evaluate our business operations as needed and to make decisions that are independent of our management. The guidelines are also intended to align the interests of directors with those of our stockholders. The Corporate Governance Guidelines set forth the practices the Board intends to follow with respect to, among other things, board composition and selection, director responsibilities, board meetings, access to senior management, succession planning, board committees, compensation and risk management.

Board Leadership Structure

Our Corporate Governance Guidelines provide that the roles of Chairman of the Board and CEO may be separated or combined as determined appropriate by the Board in light of prevailing circumstances. Currently, Jean-Pierre Sommadossi, PhD, serves in the combined role of Chairman of the Board and CEO. The Board has concluded that combining the roles of Chairman of the Board and CEO is best for Atea and our stockholders at this time. The combined role promotes unified leadership by Dr. Sommadossi and allows for a single clear focus for management to execute the Company's strategy and business plans while maintaining appropriate safeguards and oversight by independent non-management directors. The Board will continue to exercise its judgment on an ongoing basis to determine the Board leadership structure that the Board believes will provide effective leadership, oversight and direction, while optimizing the functionality of both the Board and management and facilitating effective communication between the two.

Our Corporate Governance Guidelines also provide that, if the Chairman of the Board is a member of management or does not otherwise qualify as independent, the independent directors of the Board may elect an independent Lead Director. Franklin Berger currently serves as our Lead Director. The Lead Director's responsibilities include, but are not limited to: presiding over all meetings of the Board at which the Chairman is not present, including executive sessions of the independent directors; approving Board meeting schedules and agendas; and acting as the liaison between the independent directors and the CEO and Chairman of the Board.

Board's Role in Risk Oversight

Our Board of Directors is responsible for overseeing our risk management. Our Board administers this oversight function directly and through our Audit Committee, as well as through our other standing committees of the Board that address risks inherent in their respective areas of oversight. Our management is responsible for implementing and supervising risk management and mitigation processes on a day-to-day basis.

Routinely, management discusses strategic and operational risks at regular management meetings and conducts specific strategic planning and review sessions during the year that include a focused discussion and analysis of the risks facing us. Throughout the year, management reviews these risks with the Board at regular Board and

23

Board committee meetings as part of management presentations that focus on particular business functions, operations or strategies, and presents the steps taken by management to mitigate or eliminate such risks. When a Board committee is responsible for evaluating and overseeing a particular risk, the Chair of that committee reports on it to the full Board at regular meetings of the Board so that the Board can coordinate the risk oversight role among the responsible parties. Our Board is also apprised of particular risk management matters in connection with its general oversight and approval of corporate matters and significant transactions. The Board does not believe that its role in the oversight of our risks affects the Board's leadership structure.

Code of Business Conduct and Ethics

We have a written Code of Business Conduct and Ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. The Code of Business Conduct and Ethics is accessible in the "Investors-Corporate Governance-Documents and Charters" section of our website located at www.ateapharma.com. In addition, we intend to post on our website all disclosures that are required by law or the rules of Nasdaq concerning any amendments to, or waivers from, any provision of the Code of Business Conduct and Ethics.

Insider Trading Compliance Policy

Our Board has adopted an Insider Trading Compliance Policy, which governs the purchase, sale and other dispositions of our securities by our directors, officers and employees. We believe our Insider Trading Compliance Policy is reasonably designed to promote compliance with insider trading laws, rules and regulations, and listing standards applicable to the Company. It is also our policy to comply with applicable insider trading laws and regulations with respect to transactions in our own securities. A copy of our Insider Trading Compliance Policy was filed as Exhibit 19.1 to our 2024 Form 10-K.

Anti-Hedging and Anti-Pledging Policy

The Insider Trading Compliance Policy also prohibits our directors, officers and employees and any entities they control from purchasing financial instruments such as prepaid variable forward contracts, equity swaps, collars, and exchange funds, or otherwise engaging in transactions that hedge or offset, or are designed to hedge or offset, any decrease in the market value of the Company's equity securities, or that may cause an officer, director, or employee to no longer have the same objectives as the Company's other stockholders. The Insider Trading Compliance Policy also prohibits our directors, officers and employees and any entities they control from purchasing or holding the Company's equity securities in a margin account or from pledging the Company's securities as collateral for a loan.

24

COMMITTEES OF THE BOARD

Our Board has established four standing committees-Audit, Compensation, Nominating and Corporate Governance, and Strategy and Public Policy, each of which is comprised solely of independent directors and operates under a written charter that has been approved by our Board. The charters for each of these committees are available in the "Investors-Corporate Governance-Documents and Charters" section of our website located at www.ateapharma.com.

25

26

Our Sustainability and Social Responsibility Efforts

We understand the importance of promoting responsible and meaningful environmental and social impact practices and strongly believe that doing so can create long-term benefits for our corporate strategy, risk management and corporate performance. We also understand that environmental and social matters, including matters regarding climate change and human rights, may be important to investors and we consider how to best incorporate these matters into our strategy and operations.

Our employees are integral to our long-term success, and we believe that by proactively creating a positive culture, we drive business and patient impact-together. We seek to create a positive culture by cultivating an inclusive, collaborative and open environment where all employees are empowered to contribute and be rewarded by our long-term success. We are proud that our organization represents a commitment to inclusion at every level.

Director Compensation

The Company believes that having highly qualified non-employee directors is critical to our success. Non-employee directors represent the interests of our stockholders, and they contribute their experience and wisdom to guide our Company, our strategy and our management. Compensation for our non-employee directors is designed to take into account the work required in both their ongoing oversight and governance role, and their continuous focus on driving long-term performance and stockholder value.

The Compensation Committee has the primary responsibility for reviewing non-employee director compensation and evaluating any changes in how we compensate our non-employee directors. The full Board reviews the Compensation Committee's recommendations and approves the amount and type of non-employee director compensation. The Compensation Committee periodically reviews the compensation we pay our non-employee directors and in connection with this review uses inputs and assessments prepared by our independent compensation consultant to further the Compensation Committee's understanding of current market levels of compensation being paid for board service and to gauge practices with respect to the forms of director compensation currently in use by other companies.

27

In May 2025, our Compensation Committee, with the assistance of Aon, our independent compensation consultant, performed a comprehensive review of our non-employee director compensation program. The review included a general assessment of director compensation levels and practices, an evaluation of the competitiveness of the Company's director compensation program from multiple perspectives and an overview of market trends in director compensation.

Following this review, the Compensation Committee and our Board determined to maintain for the remainder of 2025 the same non-employee director compensation structure and amounts as were in effect at the time of the review in May 2025.

Below is a description of our 2025 non-employee director compensation program.

Options granted to our non-employee directors under the non-employee director compensation program have an exercise price equal to the fair market value of our Common Stock on the date of grant, as determined under the applicable equity plan, and expire not later than ten years after the date of grant. The options granted upon a non-employee director's initial election or appointment vest in 36 substantially equal monthly installments following the date of grant, subject to the non-employee director's continuous service on the Board through each such vesting date. The options granted annually to non-employee directors vest in 12 equal monthly installments following the date of grant, such that the award will be fully vested on the first anniversary of the date of grant, subject to the non-employee director's continuous service on the Board through each such vesting date. The RSUs awarded to our non-employee directors vest in a single installment on the earlier of the first anniversary date of grant and the date of our next annual meeting of stockholders after the date of grant, subject to the non-employee director's continuous service on the Board through such vesting date. All of a non-employee director's outstanding initial and annual awards vest in full immediately prior to the occurrence of a change in control.

Non-employee director cash fees under the non-employee director compensation program are payable in arrears in four equal quarterly installments promptly following the final day of each calendar quarter, provided that the

28

amount of each payment will be prorated for any portion of a quarter that a director is not serving as a non-employee director on our Board.

We also reimburse our non-employee directors for reasonable travel and other related expenses incurred in connection with their service on our Board.

2025 Director Compensation Table

The following table sets forth information concerning the compensation of our non-employee directors in 2025:

29

The following table summarizes the equity awards outstanding at December 31, 2025 that were held by each non-employee director serving on our Board during 2025:

30

Our Audit Committee has appointed KPMG as our independent registered public accounting firm for the fiscal year ending December 31, 2026. Our Board has directed that this appointment be submitted to our stockholders for ratification at the Annual Meeting.

KPMG has audited our consolidated financial statements since the fiscal year ended December 31, 2014. Neither the accounting firm nor any of its members has any direct or indirect financial interest in or any connection with us in any capacity other than as our auditors, providing audit, tax and non-audit related services. A representative of KPMG is expected to attend the Annual Meeting, have an opportunity to make a statement and be available to respond to appropriate questions from stockholders.

Although not required, we are nonetheless seeking stockholder ratification of KPMG's appointment as our independent registered public accounting firm as a part of our commitment to strong corporate governance.

In the event that the appointment of KPMG is not ratified by our stockholders, the Audit Committee will consider this fact when it appoints the independent registered public accounting firm for the fiscal year ending December 31, 2027. Even if the appointment of KPMG is ratified, the Audit Committee retains the discretion to appoint a different independent registered public accounting firm at any time if it determines that such a change is in the interest of the Company.

KPMG Fees

The following table sets forth the fees billed to us by KPMG, our independent registered public accounting firm, during each of the last two fiscal years for audit and other services:

Audit Fees

Audit fees include fees for the audit of our consolidated financial statements and the review of unaudited interim consolidated financial statements included in our quarterly reports on Form 10-Q and assurance services associated with our SEC registration statements.

Tax Fees

Tax fees consist of fees for tax consulting services relating to the preparation of change of ownership analyses.

For the fiscal years ended December 31, 2025 and 2024, KPMG did not provide the Company with audit-related services or other non-audit services.

Audit Committee Pre-Approval Policy and Procedures

The Audit Committee pre-approves all audit services and permitted non-audit services (including the fees and terms thereof) to be provided to us by KPMG. The Audit Committee may delegate authority to one or more of its members to grant pre-approvals of audit services and permitted non-audit services provided that the decisions of such Audit Committee member or members must be presented to the full Audit Committee at its next scheduled meeting.

31

All KPMG services and fees in the fiscal years ended December 31, 2025 and 2024 were pre-approved in accordance with the pre-approval policy by the Audit Committee or an Audit Committee member with properly delegated authority.

Recommendation of the Board

32

REPORT OF THE AUDIT COMMITTEE OF THE BOARD OF DIRECTORS

The Audit Committee has reviewed Atea's audited financial statements for the fiscal year ended December 31, 2025 and has discussed these financial statements with management and Atea's independent registered public accounting firm. The Audit Committee has also received from, and discussed with, Atea's independent registered public accounting firm various communications that such independent registered public accounting firm is required to provide to the Audit Committee, including the matters required to be discussed by the Public Company Accounting Oversight Board ("PCAOB") and Securities and Exchange Commission.

Atea's independent registered public accounting firm also provided the Audit Committee with a formal written statement required by the rules of the PCAOB describing all relationships between the independent registered public accounting firm and Atea, including the disclosures required by the applicable requirements of the PCAOB regarding the independent registered public accounting firm's communications with the Audit Committee concerning independence. In addition, the Audit Committee discussed with the independent registered public accounting firm its independence from Atea.

Based on its discussions with management and the independent registered public accounting firm, and its review of the representations and information provided by management and the independent registered public accounting firm, the Audit Committee recommended to the Board that the audited financial statements be included in Atea's Annual Report on Form 10-K for the fiscal year ended December 31, 2025.

Sincerely,

Barbara Duncan (Chair)

Franklin Berger

Arthur Kirsch

Bruno Lucidi

33

Our Board is committed to excellence in governance. As part of this commitment and as required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 ("Dodd-Frank Act") and Section 14A(a)(1) of the Exchange Act, our stockholders have the opportunity to approve, on an advisory (non-binding) basis, the compensation of our named executive officers. This proposal is commonly known as a "Say-on-Pay Vote." The Say-on-Pay Vote is not intended to address any specific item of compensation, but rather the overall compensation of our named executive officers and our compensation philosophy, policies and practices as described in this Proxy Statement.

The compensation of our named executive officers is described below in the "Executive Officer and Director Compensation" section of this Proxy Statement. We believe that our compensation policies and decisions are based on principles that reflect a "pay-for-performance" philosophy and are strongly aligned with the interests of our stockholders and consistent with market practices. Our executive compensation program is designed to enable us to attract and retain in a competitive and dynamic market talented and experienced executives who are effectively incentivized to drive the attainment of Company performance goals that are expected to promote our success and create long-term stockholder value.

Accordingly, we ask our stockholders to vote "FOR" the following resolution at the Annual Meeting:

"RESOLVED, that the Company's stockholders approve, on an advisory (non-binding) basis, the compensation of the named executive officers, as disclosed in the Company's Proxy Statement for the 2026 Annual Meeting of Stockholders pursuant to the compensation disclosure rules of the Securities and Exchange Commission, including the Named Executive Officer Compensation Overview, the compensation tables and narrative discussion."

As an advisory approval, this proposal is not binding upon the Board or the Compensation Committee. However, the Board and Compensation Committee value the opinions of our stockholders expressed through your vote on this proposal. The Board and Compensation Committee intends to carefully consider the outcome of this vote in making future compensation decisions for our named executive officers.

In accordance with the "once a year" frequency of Say-on-Pay Votes that our stockholders approved at our 2022 annual meeting of stockholders, the Board has determined that Say-on-Pay Votes will be held on an annual basis. The Board expects the next Say-on-Pay Vote to be held at our 2027 annual meeting of stockholders.

Recommendation of the Board

34

EXECUTIVE OFFICERS

The following table identifies our current executive officers:

Non-Director Executive Bios

Andrea Corcoran has served as our Chief Financial Officer since October 2020, our Secretary since September 2014 and our Executive Vice President, Legal since December 2013. Ms. Corcoran also served as Executive Vice President, Administration from September 2014 to October 2020. Prior to joining us, Ms. Corcoran served as Senior Vice President, Strategy and Finance at iBio, Inc., from 2011 to 2012, as General Counsel and Secretary at Tolerx, Inc., from 2007 to 2011, and as Executive Vice President of Idenix Pharmaceuticals, Inc. from 1998 to 2007. Ms. Corcoran received her JD from Boston College Law School and her BS from Providence College.

Janet Hammond, MD, PhD has served as our Chief Development Officer since August 2020. Prior to joining us, Dr. Hammond served as Vice President and Therapeutic Area Head for General Medicine and Infectious Disease Development at AbbVie, Inc., a biopharmaceutical company, from November 2016 to August 2020, and as Senior Vice President, Global Head of Infectious Diseases and Head of Pharmaceutical Research and Early Development China at F. Hoffmann-La Roche from March 2011 to November 2016. Dr. Hammond has also served on the board of directors of Enterprise Therapeutics Ltd., a privately held biopharmaceutical company, since May 2024. Dr. Hammond received her MD and PhD from the University of Cape Town, South Africa, and her ScM in Clinical Investigation from Johns Hopkins University School of Hygiene and Public Health.

Maria Arantxa Horga, MD has served as our Chief Medical Officer since January 2021 and previously served as our Acting Chief Medical Officer since October 2020 and as Executive Vice President, Clinical Sciences since August 2020. Prior to joining us, Dr. Horga served as Vice President, Pharmacovigilance and Medical Affairs at Biohaven Pharmaceuticals, Inc. from October 2019 to August 2020. Prior to that, Dr. Horga served as Vice President, Global Head of Clinical Program Execution, Site Head of the Roche NY Innovation Center from July 2017 to August 2019, and as Global Head of Translational Medicine, Infectious Diseases at F. Hoffmann-La Roche from 2012 to 2016. Dr. Horga received her MD from the Santander School of Medicine and completed her residency in Pediatrics and a fellowship in Pediatric Infectious Diseases at the Mount Sinai School of Medicine.

John Vavricka has served as our Chief Commercial Officer since October 2018. From March 2015 to June 2021, Mr. Vavricka also served as the Chief Executive Officer of Biothea Pharma, Inc., which he co-founded. Prior to that Mr. Vavricka founded and served as the Chief Executive Officer and President of Iroko Pharmaceuticals, Inc., from 2007 to 2015. Mr. Vavricka received his BS from Northwestern University.

Wayne Foster has served as our Executive Vice President, Finance and Chief Accounting Officer since January 2022 and previously served as our Senior Vice President, Finance and Administration from December 2019 to January 2022. Before joining us, Mr. Foster served as Vice President of Finance at Mersana Therapeutics, Inc., from January 2012 to September 2019. Mr. Foster received his BBA from the University of Massachusetts Amherst.

35

Our NEOs for 2025 were:

Our Compensation Committee designs incentives based on Company performance that both emphasize the creation of sustainable long-term stockholder value and attract, motivate and retain highly qualified and experienced executives.

Our compensation design promotes performance alignment and protects stockholder interests.

36

For 2025, the resulting Target Pay mix was:

Key Elements of 2025 Compensation

37

Our Board and management team value the views of our stockholders. Consistent with our commitment to enabling open and ongoing dialogue with stockholders, we actively engage and meet with stockholders throughout the year and discuss a variety of topics, including our research and development activities, commercialization plans, business strategy, financial outlook, and corporate governance matters.

During 2025, we conducted a robust and comprehensive outreach effort, engaging both existing and potential stockholders through a broad range of meetings and interactions designed to communicate our strategy, governance practices, and long-term priorities, while also soliciting investor feedback. Following the 2025 Annual Meeting, we offered engagement opportunities to stockholders representing more than 50% of our outstanding shares of common stock. Stockholders with whom we engaged-representing the majority of responding share ownership-generally focused discussions on our strategic direction, operational execution, capital stewardship, and governance practices.

When establishing 2025 compensation packages, our Compensation Committee utilized the pay elements detailed below to appropriately balance fixed and "at-risk," performance-based compensation, short- and long-term incentives and cash and non-cash components while aligning the interests of our NEOs with those of our stockholders. We consider compensation to be "at-risk" if it is dependent upon stock price appreciation or if it is subject to achievement of rigorous strategic, business or operational goals.

Though the Compensation Committee has not adopted any formal or informal policies or guidelines that specify the allocation of compensation between these elements, consistent with our "pay-for-performance" philosophy, the Compensation Committee has determined that NEO compensation packages must include an emphasis on and substantial portion of variable, at-risk pay, with a very meaningful portion that is performance-based, while ensuring adequate base salary to attract and retain talent.

Annual Base Salary is the only fixed component of executive compensation. Base salaries for our NEOs are designed to provide fair and competitive stable compensation for services rendered throughout the year. In setting base salaries, the Compensation Committee considers each NEO's experience, skills, and responsibilities, market data for similar roles at peer companies, internal pay equity and the recommendations of our CEO for executives other than himself, and may also draw upon the experience of members of our Board with executives in similar roles at other companies. The Compensation Committee reviews executive base salaries each year - typically in connection with our annual performance review process - and may adjust appropriately to align with market competitive pay levels, or to account for individual responsibilities, performance, experience and promotions.

38

In January 2025, the Compensation Committee reviewed the base salaries of each NEO pursuant to the process outlined above and determined to increase the base salaries of each NEO by 3% to maintain market competitiveness in a time of increasing cost-of-living. Our CEO elected not to receive a base salary increase for 2025 in consideration of the Company's efforts to reduce costs which included, in January 2025, a reduction in the Company's workforce of approximately 25%.

The Compensation Committee has designed our annual performance-based cash incentive compensation program based upon specified preset annual corporate goals to incentivize and reward our NEOs for performance and achievement of key short term operational and corporate goals. Since this element of compensation is directly linked to the achievement of specified objectives and goals, the actual payout amounts vary from year to year based upon the level of Company and, as applicable, individual performance. For 2025, actual payouts were based solely on Company performance.

The processes for establishing 2025 target opportunities, setting and determining achievement of performance goals and determining level of payout was consistent with the processes and practices utilized in prior years.

Target Opportunities

At or immediately prior to the start of each year, the Compensation Committee establishes the annual performance-based cash bonus opportunity for each NEO based upon a percentage of his or her base salary with consideration to each executive officer's accountability, scope of responsibilities, and potential impact on our performance, as well as recommendations from an independent external consultant, Aon (as discussed in more detail below), regarding market compensation levels. The 2025 cash bonus opportunities for all our NEOs, excluding only our CFO, expressed as a percentage of base salary, did not change relative to 2024. For our CFO, in 2025, the cash bonus opportunity, expressed as a percentage of base salary, increased from 40% to 45%.

39

Establishment and Assessment of 2025 Performance Goals

As a pre-commercial biopharmaceutical company, we do not have material revenue or profits at this stage and our success is best measured by achievement of research and development milestones and other key strategic and operational goals. Thus, the annual performance-based cash incentive is designed to directly tie our executives' pay outcomes to achievement of these key goals.

The 2025 corporate goals and the weight attributable to each goal were approved by our Board in the first quarter of 2025, based upon the recommendation of the Compensation Committee. The Compensation Committee formulated the goals after obtaining input from management regarding the annual operating plan, expected research and development advancements and related risks.

The following table outlines the preset goals underpinning the annual performance-based cash incentives, the Compensation Committee's assessment of performance against the goals, and the resulting level of achievement attained:

40

41

Determination of Payouts

In the first quarter of 2026, the Compensation Committee, considering our CEO's recommendation regarding the level of achievement against each goal, assessed our 2025 performance against our pre-specified 2025 corporate goals. The Compensation Committee concluded that achievements in the HCV clinical/regulatory, HCV Preclinical/CMC/Commercial, Discovery, and corporate activities met the pre-specified goals. These determinations resulted in the Compensation Committee recommending to the Board that it establish a 100% level of achievement rating for the corporate performance goals in 2025.

The Board subsequently approved the corporate performance rating of 100% achievement and the annual awards were paid in February 2026 at 100% of their respective target opportunity. The table below shows the 2025 annual cash performance-based incentive compensation paid to each NEO:

Our equity award program is a key component of our overall total compensation program and is designed to align the interests of our NEOs with those of our stockholders by motivating our NEOs to achieve the realization of our corporate strategy and the creation of stockholder value. Additionally, our equity award program also serves as a retention tool as vesting of the equity awards is tied to a multi-year period requiring the NEOs' continued service with us during such period.

42

For 2025, the Compensation Committee structured the long-term equity incentive mix to include PSUs and stock options to motivate:

PSUs

The rationale for the use of PSUs in 2025 compensation included:

The 2025 PSUs were designed to include performance metrics that capture key regulatory and commercial milestones related to the realization of the Company's strategic plans, with a three year performance period continuing until January 2028.

Stock Options

Consistent with what we believe to be the prevailing market practice for companies in our industry at our stage of development, we have historically used stock option awards to compensate our NEOs in the form of initial new hire grants in connection with the commencement of employment, and thereafter on an annual basis in connection with our annual executive compensation reviews.

The rationale for continued utilization of stock options in 2025 compensation included:

The exercise price of our stock options equals the fair market value of a share of our Common Stock on the date of grant, as determined under our equity incentive plan. As a result, the holder will not realize value from an option if our stock price does not appreciate above the grant date stock price.

2025 Grants

In determining the number of PSUs and options to grant as part of the 2025 equity awards, the Compensation Committee considered a number of factors, including among others: the equity award value, the ownership percentage of the Company represented by the equity award, the equity award as a portion of direct compensation, the retentive value of the NEO's existing unvested and total equity incentive holdings, the NEO's level of responsibility within our Company, equity compensation in relation to the general practices of our 2025 Peer Group (as defined and discussed below) and total annual and cumulative dilution associated with the current and prior equity awards.

43

Note: The Compensation Committee considered the PSU value awarded to be equal to the number of PSUs to be granted multiplied by a 30-day average share price, and considered the stock option value awarded to be equal to the number of stock options to be granted multiplied by a 30-day average share price times a Black-Scholes factor.

The 2025 PSUs will cliff-vest in January 2028 based on the level of achievement of specific regulatory and commercialization milestones over the three-year performance period. For the PSUs granted in January 2025, the performance criteria must be realized over a three-year period beginning February 1, 2025 and concluding January 31, 2028. Provided that a minimum of one of the four performance criteria are achieved during the performance period, a tiered payout to executives from 50% to 200% of the target number of PSUs will be earned as follows: if the Compensation Committee determines that (i) one of the performance criteria is achieved, 50% of the target PSUs will be earned, (ii) two performance criteria were achieved, 100% of the target PSUs will be earned, (iii) three performance criteria were achieved, 150% of the target PSUs will be earned, or (iv) four performance criteria were achieved, 200% of the target PSUs will be earned.

Stock options awarded to our NEOs in 2025 as a part of annual compensation reviews vest and become exercisable monthly as to 1/48th of the shares underlying the option until the award is fully vested on the fourth anniversary of the date of grant.

Vesting of stock options and PSUs generally ceases on termination of employment, and exercise rights for vested stock options generally cease three months after termination of employment. In specified termination and change in control circumstances, equity awards held by our NEOs are subject to accelerated vesting. See "Potential Payments Upon Termination or Change in Control" below for further information.

Prior to the exercise of a stock option or vesting of the PSUs, the holder has no rights as a stockholder with respect to the shares underlying such equity award, including no voting rights and no right to receive dividends or dividend equivalents.

2022 PSUs

In January 2022, the Compensation Committee determined to add PSUs to the long-term equity incentive program for our NEOs and other senior executives, in addition to stock options. This decision further reflected the Compensation Committee's "pay for performance philosophy." The PSUs were designed to further incent our executives and align the interests of our NEOs with the interests of our stockholders while adding a retention tool as the PSUs would result in realized value for the recipient only if the designated performance criteria are achieved and the PSU recipient remains an Atea employee through the performance period and for the additional vesting period thereafter. For the PSUs granted in January 2022, the performance criteria must have been realized over a three-year period beginning February 1, 2022 and concluding January 31, 2025. Provided that a minimum of 2 of the 6 performance criteria are achieved during the performance period, a tiered payout to executives from 50% to 200% of the target number of PSUs will be earned as follows: if the Compensation Committee determines that (i) two performance criteria were achieved, 50% of the target PSUs would be earned, (ii) three performance criteria were achieved, 100% of the target PSUs would be earned, (iii) four performance criteria were achieved, 150% of the target PSUs would be earned, or (iv) five performance criteria were achieved, 200% of the target PSUs would be earned. The Compensation Committee determined that two of the performance criteria, the generation of positive HCV Phase 2 clinical trial results and the generation of positive data supporting the initiation of a COVID-19

44

clinical trial, were achieved. The earned PSUs vested as to 50% on the date of the Compensation Committee's determination and will vest as to the remaining 50% on the first anniversary of such determination, subject to the executive remaining in the service of the Company at each such time. See "Potential Payments Upon Termination or Change in Control - PSUs" below for a description of the vesting of the PSUs granted to our NEOs in connection with a change in control and upon certain terminations of employment.

Health and Welfare Benefits

All of our NEOs are eligible to participate in our employee benefit plans, including our medical, dental, vision, disability and life insurance plans, in each case on the same basis as all of our other employees.

Section 401(k) Plan

Our NEOs are eligible to participate, on the same basis as all of our other employees, in a defined contribution retirement plan that provides eligible employees with an opportunity to save for retirement on a tax-advantaged basis. Eligible employees may defer eligible compensation on a pre-tax or after-tax (Roth) basis, up to the statutorily prescribed annual limits on contributions under the Internal Revenue Code of 1986, as amended (the "Code"). Contributions are allocated to each participant's individual account and are then invested in selected investment alternatives according to the participant's directions. We currently match 100% of employee contributions of the first 3% of eligible compensation, and 50% of contributions on the next 2% of eligible compensation. Participants are immediately and fully vested in all contributions. The 401(k) plan is intended to be qualified under Section 401(a) of the Code, and the 401(k) plan's related trust is intended to be tax-exempt under Section 501(a) of the Code. As a tax-qualified retirement plan, contributions to the 401(k) plan (except for Roth contributions) and earnings on those contributions are not taxable to participants until distributed from the 401(k) plan.

Employee Stock Purchase Plan

Pursuant to our employee stock purchase plan, our employees, including each of our NEOs other than our CEO, have an opportunity to purchase our Common Stock at a discount on a tax-qualified basis through payroll deductions. The employee stock purchase plan is designed to qualify as an "employee stock purchase plan" under Section 423 of the Internal Revenue Code. The purpose of the employee stock purchase plan is to encourage our employees, including our named executive officers, to become our stockholders and better align their interests with those of our other stockholders.

Perquisites

We generally do not provide perquisites or personal benefits to our NEOs, except in limited circumstances. We did not provide any such perquisites or personal benefits to any NEO in 2025.

45

Post-Employment Compensation

Our NEOs are entitled to certain severance and change of control payments and benefits as described in more detail below (see sections "Agreements with Named Executive Officers" and "Potential Payments Upon Termination or Change of Control"). These agreements provide for a combination of a cash severance payment, continued health benefits and acceleration of vesting on outstanding equity awards in specified circumstances. Acceleration of vesting of stock options and restricted stock units is subject to a "double trigger" arrangement, meaning that vesting acceleration occurs only in the event of a change in control of the Company in connection with or followed by a termination of employment without cause by us, or with good reason by the NEO.

Given the industry in which we participate and the range of strategic initiatives that we may explore, we believe reasonable and competitive severance and change in control payment and benefit arrangements are an essential element of our executive compensation package and assist us in recruiting and retaining a talented executive team. We also believe such payments and benefits are in the best interests of our stockholders because they incentivize senior executives to continue to strive to achieve stockholder value in connection with change-in-control situations, particularly where the possibility of a change-in-control and the related uncertainty may lead to the departure or distraction of senior executives to the detriment of our Company and our stockholders.

Process for Setting Executive Compensation

Role of the Compensation Committee and the Board

Annually, our Compensation Committee, which is comprised entirely of independent directors, exercises the authority delegated to it by our Board and exercises its oversight role to:

Our Compensation Committee reviews the mix of compensation elements to ensure performance-based compensation is an appropriate proportion of overall compensation and is aligned with our business goals and strategy. Additionally, the Compensation Committee reviews the overall corporate performance for the year against goals annually approved by the Board and, as applicable, the individual performance of our NEOs and other executive officers. These annual performance reviews are a critical component in the determination by the Compensation Committee of annual cash and equity incentive awards for our NEOs and other executives. Our Compensation Committee may also delegate to one or more executive officers of the Company the power to grant options or other stock or equity-based awards pursuant to our equity-based plan to employees of the Company or any subsidiary of the Company who are not officers or directors of the Company, and may delegate authority to one or more subcommittees as it deems appropriate.

Our Board receives recommendations from the Compensation Committee and retains the authority to approve those matters that have been delegated to the Compensation Committee, including establishing the key annual operational goals under our annual performance-based cash incentive plan and determining the level of achievement of such goals following year-end. The Board also retains authority to approve all components and levels of compensation awarded to our CEO.

Role of Management

Our Compensation Committee works with management, including our CEO, when reviewing and setting executive compensation. Management generally provides information on corporate and individual performance, updates on peer performance, and works with the independent compensation consultant to identify meaningful external market compensation data.

46

Our CEO provides:

Role of the Independent Compensation Consultant

Since 2018, the Compensation Committee has engaged an independent external consultant, Aon's Human Capital Solutions Practice, a division of Aon plc ("Aon"), to provide information and to advise on overall compensation matters for all employees, including our NEOs, and non-employee members of our Board. In 2025, Aon's services included:

While Aon works with management to source market data and to arrive at market matches for new hires and promotions of executive officers, Aon reports directly to the Compensation Committee. Aon consultants attend meetings of the Compensation Committee when requested to do so.

The Compensation Committee has assessed the independence of Aon pursuant to SEC and Nasdaq rules. In doing so, the Compensation Committee considered each of the factors set forth by the SEC and Nasdaq with respect to the determination of independence of a compensation consultant. The Compensation Committee also considered the nature and amount of work performed for the Compensation Committee by Aon and the fees paid for those services in relation to the firm's total revenues.

Based on its consideration of the foregoing and other relevant factors, the Compensation Committee concluded that there were no conflicts of interest, and that Aon is independent. During 2025, Aon did not provide any services to us other than the services described above.

Role of Market Data

The Compensation Committee uses competitive market analyses from a group of peer companies as one input and reference point for compensation decisions when reviewing our executive compensation levels and practices. The Compensation Committee also uses market data from broader Radford Global Life Sciences Compensation surveys and its own knowledge and judgment in evaluating market data and making compensation decisions.

47

However, survey data is not used to benchmark the amount of total compensation or any specific element of compensation for the NEOs.

Our Compensation Committee reviews the companies in our peer group annually, based on the criteria noted below, and makes adjustments as necessary to ensure the peer group continues to properly reflect the market in which we compete for talented executives.

In its establishment of a peer group of publicly traded companies in the biopharmaceutical and biotechnology industry, the Compensation Committee, using information and assistance provided by Aon, generally considers several factors and criteria including the following:

More specifically, when evaluating our peer group for 2025 compensation decisions, the Compensation Committee focused on companies with a market capitalization range of 1/4 to 4x the Company's market capitalization and headcount below 225 employees. Based on these criteria, for the executive compensation review conducted by the Compensation Committee in December 2024 and January 2025 at which 2025 base salaries and target annual performance-based cash incentive levels were determined and equity compensation for our NEOs was awarded, our Compensation Committee analyzed the pay practices of the following peer group approved by the Compensation Committee in October 2024, which we refer to as our 2025 Peer Group:

Changes in the 2025 Peer Group compared to the peer group that we used to establish 2024 compensation for our NEOs and other executives included the removal of: Kura Oncology, Rocket Pharmaceuticals, Inc. and Summit Therapeutics Inc. and due to their respective market capitalization being outside our defined range, as well as Point Biopharma Global Inc. (acquired by Eli Lilly) and VBI Vaccines Inc. (filed for bankruptcy). To ensure an appropriate number of peers for reference, five companies meeting our criteria for the 2025 Peer Group, being 89bio, Inc., Annexion, Inc., Assembly Biosciences, Inc., Gossamer Bio, Inc. and Inozyme Pharma, Inc. were added.

Additionally, when considering the establishment of 2025 compensation levels for our NEOs, the Compensation Committee, upon recommendation from Aon, supplemented the 2025 Peer Group proxy data with data derived from the Radford 2024 Global Life Science Survey for public biopharmaceutical companies which had a market capitalization between $100 million and $1.2 billion and less than 225 employees. This survey data was used to obtain a general understanding of the compensation practices of companies similar to ours at the time. To arrive at competitive market compensation, Aon blended the survey data with publicly available proxy data where possible.

The processes described above, the roles of the Board, Compensation Committee, management and the independent compensation consultant, and the manner in which data were assembled and utilized for establishing 2025 executive compensation were consistent with prior years and remain consistent with the current processes, roles and uses.

48

Other Polices and Considerations

Compensation Recovery Policy (Clawback Policy)

Our Board of Directors has adopted a compensation recovery, or clawback, policy in accordance with the Nasdaq listing standards and Exchange Act Rule 10D-1. If we must restate our financial results as reported in a periodic or other report filed with the SEC to correct an accounting error due to material noncompliance with any financial reporting requirement under the U.S. securities laws, our Board must generally recover all incentive compensation, both cash and equity-based, awarded or paid to an executive officer covered by the policy to the extent any such compensation would not have been awarded or paid to such officer based on the restated financial results during the three completed fiscal years preceding the date on which the Company is required to prepare the restatement. This policy was adopted in 2023 after the final rule under the Dodd-Frank Act was promulgated by Nasdaq, and it became effective as of October 2, 2023, when the final rule went into effect.

Compensation Risk Assessment

Each year, the Compensation Committee reviews our compensation policies and programs to assess whether these policies and programs may encourage our employees and executives to take inappropriate risks. Specifically, the Compensation Committee reviews our current compensation plans, including the mix of fixed and variable compensation, performance metrics, program oversight, measurement and payout timing, discretion and caps on short-term incentives, award size, vesting schedules and other terms of long-term equity incentives as well as other incentive opportunities and their features. After reviewing each of our current compensation plans, the Compensation Committee determined that our compensation program does not create risks that are reasonably likely to have a material adverse effect on our Company as a whole.

Rule 10b5-1 Sales Plans

Our directors and executive officers, including our NEOs, may adopt written trading plans pursuant to Rule 10b5-1 under the Exchange Act, known as Rule 10b5-1 plans. Under a Rule 10b5-1 plan, a broker executes trades for a director or executive officer under a previously established contract, plan or instruction to trade in the Company's Common Stock, entered into in good faith and in accordance with the terms of Rule 10b5-1, without further direction from the director or executive officer. Our directors and executive officers also may buy or sell additional shares outside of a Rule 10b5-1 plan when they are not in possession of material nonpublic information subject to compliance with the terms of our Insider Trading Compliance Policy.

Accounting and Tax Considerations

Under FASB ASC Topic 718, we are required to estimate and record an expense for each share-based payment award (including stock options, RSUs and PSUs) over the vesting period of the award. We record share-based compensation expense on an ongoing basis according to FASB ASC Topic 718.

Under Section 162(m) of the Code ("Section 162(m)"), compensation that exceeds $1 million per taxable year paid to certain current and former executive officers of a publicly held corporation is generally non-deductible.

Although the Compensation Committee considers tax implications as one factor in determining executive compensation, the Compensation Committee also looks at other factors in making its decisions and retains the flexibility to provide compensation for the Company's executive officers in a manner consistent with the goals of the Company's executive compensation program and the best interests of the Company and its stockholders, which may include providing for compensation that is not deductible by the Company due to the deduction limit under Section 162(m).

49

NAMED EXECUTIVE OFFICER COMPENSATION

2025 Summary Compensation Table

The table below summarizes the total compensation for each of our NEOs for the years presented.