New Data Showcasing Favorable Profile of Bemnifosbuvir for Treatment of COVID-19 and Hepatitis C to be Presented at 2023 International Conference on Antiviral Research

Atea Pharmaceuticals, Inc. (Nasdaq: AVIR) (“Atea”), a clinical-stage biopharmaceutical company engaged in the discovery and development of oral direct acting therapeutics for several viral diseases, today announced six upcoming presentations at the 36th International Conference on Antiviral Research (ICAR), which will take place March 13-17, 2023 in Lyon, France.

Presentation details are as follows:

Poster Number: 411Title: The Combination of Bemnifosbuvir (BEM) and Ruzasvir (RZR), the HCV NS5B and NS5A Inhibitors, Demonstrates Potent In Vitro Synergistic Antiviral Activity and In Vivo Preclinical Safety Without Adverse Interactions Session: Influenza, RSV, and Other Respiratory Viruses SessionPoster Number: 537Title: Low Risk of Drug-Drug Interactions (DDIs) for Bemnifosbuvir (BEM) Based Upon In Vitro Metabolism and Transporter Interaction Studies Session: Influenza, RSV, and Other Respiratory Viruses Session

Poster Number: 549Title: Pharmacokinetics and Metabolism of [14C]-Bemnifosbuvir in Healthy Male ParticipantsSession: Influenza, RSV, and Other Respiratory Viruses Session

Oral Presentation Number: 019Title: Bemnifosbuvir (BEM, AT-527) a Potent Inhibitor of SARS-CoV-2 Variants of Concern (VOC), and a Promising Oral Antiviral with a High Resistance Barrier for Treatment of COVID-19 and other Coronaviruses InfectionsSession: Influenza, RSV, and Other Respiratory Viruses Session

Oral Presentation Number: 046Title: AT-752 Targets Multiple Sites and Activities on the Dengue Virus Replication Enzyme NS5Session: SARS-CoV-2, Arboviruses, Other Biothreat Viruses, andBroad Spectrum Antivirals II Session

Oral Presentation Number: 047Title: Five Cellular Enzymes in the Activation Pathway of Bemnifosbuvir, a Drug-Candidate Against SARS-CoV-2 InfectionsSession: SARS-CoV-2, Arboviruses, Other Biothreat Viruses, andBroad Spectrum Antivirals II Session

About Atea PharmaceuticalsAtea is a clinical stage biopharmaceutical company focused on discovering, developing and commercializing oral therapies to address the unmet medical needs of patients with serious viral infections. Leveraging the Company’s deep understanding of antiviral drug development, nucleos(t)ide chemistry, biology, biochemistry and virology, Atea has built a proprietary nucleos(t)ide prodrug platform to develop novel product candidates to treat single stranded ribonucleic acid, or ssRNA, viruses, which are a prevalent cause of serious viral diseases. Atea plans to continue to build its pipeline of antiviral product candidates by augmenting its nucleos(t)ide platform with other classes of antivirals that may be used in combination with its nucleos(t)ide product candidates. Currently, Atea is focused on the development of orally-available antiviral agents for serious viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, and hepatitis C virus (HCV). For more information, please visit www.ateapharma.com.

Forward-Looking StatementsThis press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding our expectations surrounding the potential of our product candidates, including bemnifosbuvir combination product candidates, and expectations regarding our pipeline, including trial design and development timelines. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the uncertainty around and costs associated with the clinical development of bemnifosbuvir as a potential treatment for COVID-19 and the combination of bemnifosbuvir and ruzasvir as a potential treatment for HCV. These and other important factors discussed under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2022 and our other filings with the SEC could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

Contacts

Jonae BarnesSVP, Investor Relations and Corporate [e-mail]

Will O’ConnorStern Investor Relations [e-mail]