Atea Pharmaceuticals, Inc.

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):

Notice of Annual Meeting of Stockholders

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, therecord 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 contactus@ateapharma.com 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 toread 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

Letter from the Board

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.

Important Notice Regarding the Availability of Proxy Materialsfor the Annual Meeting to be Held on June 18, 2026The Proxy Statement and our Annual Report for the year ended December 31, 2025 are available at www.proxyvote.com and in the Investor section of our website at www.ateapharma.com.

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 visitingwww.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:

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FOR the election of Jerome Adams, MD, MPH, Howard Berman, PhD and Barbara Duncan as Class III Directors;

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FOR the ratification of the appointment of KPMG as our independent registered public accounting firm for the fiscal year ending December 31, 2026; and

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FOR the approval, on advisory (non-binding) basis of the compensation of the Company’s named executive officers.

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.