A leader in the discovery of oral direct-acting antiviral therapies.

Derived from Atea’s nucleos(t)ide platform, bemnifosbuvir (AT-527) is an oral direct acting antiviral being evaluated in the global Phase 3 SUNRISE-3 registrational trial for the treatment of COVID-19. Bemnifosbuvir targets the SARS-CoV-2 RNA polymerase (nsp12), a highly conserved gene that is unlikely to change as the virus mutates and new variants continue to emerge. This gene is responsible for both replication and transcription of SARS-CoV-2. Bemnifosbuvir has a unique mechanism of action, with dual targets consisting of chain termination (RdRp) and nucleotityltransferase (NiRAN) inhibition, which has the potential to create a high barrier to resistance.

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Innovative discovery and efficient development of potentially transformative therapies for patients with life-threatening viral diseases.

Atea is a clinical stage biopharmaceutical company working to address unmet medical needs with innovative oral antiviral therapies.


The power of our purine nucleotide prodrug platform.

Leveraging our platform, we have discovered and are rapidly advancing novel oral direct-acting antiviral drug candidates. Utilizing unique chemical modifications, these product candidates are designed to have the potential for enhanced antiviral activity and selectivity.

A network of hubs and spokes is suspended, representing the idea of a modular platform.


Bemnifosbuvir addresses the key challenges of the COVID-19 pandemic and beyond.

For the treatment of COVID-19, we need transformational solutions, and we believe that oral, safe, direct-acting antivirals can play an essential role worldwide. The value and global health impact of a direct-acting antiviral is to rapidly inhibit viral replication in the early phase of infection, which has the effect of reducing disease progression and curtailing the spread of infection.

While vaccines will play an important role in mitigating the COVID-19 pandemic, we will need treatment options to stay ahead of the virus.

Bemnifosbuvir is an oral, direct-acting antiviral drug candidate that is being evaluated for COVID-19.

Similar to Tamiflu®

Complementary medical intervention to vaccination

Significant advantages vs antibodies

Oral administration has significant advantages:

  • convenient for patients and healthcare workers
  • global reach
  • manufacture
  • scale-up
  • cost
Effective vs. mutations

Highly-conserved target has potential to enable antiviral activity in the presence of multiple variants

anticipated to be effective again st future coronaviruses

Antiviral activity against potential future coronaviruses beyond SARS-CoV-2 anticipated


Follow our progress.

See updates on bemnifosbuvir, other Atea product candidates and company news.

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

Low risk for drug-drug interactions with bemnifosbuvir based upon results from in vitro metabolism and transporter studies Bemnifosbuvir retains activity against all SARS -CoV-2 variants of concern evaluated as well as other human coronaviruses such as HCoV-229E, HCoV-OC43, and SARS-CoV-1 Favorable

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

BOSTON, March 08, 2023 (GLOBE NEWSWIRE) -- 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 36 th

Atea Pharmaceuticals Reports Fourth Quarter and Full Year 2022 Financial Results and Provides Business Update

Phase 3 SUNRISE-3 trial evaluating bemnifosbuvir for treatment of COVID-19 in high-risk patients continues enrollment; interim analysis expected in 2H23 Phase 2 trial evaluating combination of bemnifosbuvir and ruzasvir for treatment of HCV to start enrollment in 2Q23; initial results expected by