This section highlights FDA-related milestones and regulatory updates for drugs developed by Atea Pharmaceuticals (AVIR).
Over the past two years, Atea Pharmaceuticals has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
AT-587, C-BEYOND, and Bemnifosbuvir. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
AT-587 FDA Regulatory Events
AT-587 is a drug developed by Atea Pharmaceuticals for the following indication: Treatment of Hepatitis E Virus.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- AT-587
- Announced Date:
- February 24, 2026
- Indication:
- Treatment of Hepatitis E Virus
Announcement
Atea Pharmaceuticals, Inc. announced in vitro results showing that two proprietary oral nucleotide analogs, AT-587 and AT-2490, exhibit promising antiviral profiles as potential first-in-class inhibitors for the treatment of Hepatitis E virus (HEV) infection, a positive-sense, single-stranded RNA virus that primarily infects liver cells.
AI Summary
Atea Pharmaceuticals reported in vitro results showing two proprietary oral nucleotide analogs, AT-587 and AT-2490, have strong antiviral activity against Hepatitis E virus (HEV). HEV is a positive-sense, single-stranded RNA virus that mainly infects liver cells. In lab tests, AT-587 was highly potent across HEV strains and AT-2490 also showed a promising antiviral profile. Both compounds act as nucleotide analog inhibitors, a type of drug that can block viral replication, and they are being developed as potential first-in-class oral treatments for HEV.
The company selected AT-587 as the lead candidate for its HEV program and plans to start a Phase 1 clinical trial around mid-2026. The preclinical data were shared at a scientific meeting, supporting the rationale to move these candidates into human testing. These results aim to address the current lack of approved, targeted therapies for HEV infections.
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C-BEYOND FDA Regulatory Events
C-BEYOND is a drug developed by Atea Pharmaceuticals for the following indication: the treatment of hepatitis C virus.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- C-BEYOND
- Announced Date:
- December 22, 2025
- Indication:
- the treatment of hepatitis C virus
Announcement
Atea Pharmaceuticals, Inc. announced completion of enrollment of more than 880 treatment-naïve patients in the C-BEYOND Phase 3 trial evaluating the fixed-dose combination (FDC) regimen of bemnifosbuvir and ruzasvir compared to the FDC regimen of sofosbuvir and velpatasvir for the treatment of hepatitis C virus (HCV). C-BEYOND is being conducted at approximately 120 clinical trial sites in the US and Canada.
AI Summary
Atea Pharmaceuticals announced completion of enrollment of more than 880 treatment‑naïve patients in C‑BEYOND, a Phase 3 head‑to‑head trial comparing a fixed‑dose combination (FDC) of bemnifosbuvir and ruzasvir versus the FDC of sofosbuvir and velpatasvir for hepatitis C. The study is being conducted at about 120 clinical sites in the US and Canada.
The bemnifosbuvir/ruzasvir regimen is taken once daily for 8 weeks in patients without cirrhosis and 12 weeks in those with compensated cirrhosis, while the comparator is taken once daily for 12 weeks for all patients. The primary endpoint is HCV RNA below the lower limit of quantitation at 24 weeks from treatment start (SVR12). Topline Phase 3 results are expected mid‑2026.
Completing enrollment is a major milestone for Atea’s HCV program. If the shorter, well‑tolerated regimen shows strong results with low drug‑drug interaction risk, it could broaden treatment options and help reduce the global burden of HCV.
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Bemnifosbuvir FDA Regulatory Timeline and Events
Bemnifosbuvir is a drug developed by Atea Pharmaceuticals for the following indication: COVID-19.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Bemnifosbuvir
- Announced Date:
- November 7, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced the presentation of new modeling data predicting that the Company's combination regimen of bemnifosbuvir (BEM), a nucleotide analog polymerase inhibitor, and ruzasvir (RZR), an NS5A inhibitor, achieved near-complete inhibition of both viral replication and assembly and secretion into the bloodstream, with a modeled time to cure of approximately 7 to 8 weeks.
AI Summary
Atea Pharmaceuticals presented new computer modeling data showing its oral combination of bemnifosbuvir (BEM) and ruzasvir (RZR) can almost completely block hepatitis C virus replication, assembly, and release into the blood. The model predicts that patients could be cured in about 7 to 8 weeks with this two-drug regimen.
These findings back up Phase 2 results in which an 8-week treatment with the fixed-dose combination (FDC) achieved a sustained virologic response at 12 weeks after treatment (SVR12) of 98% in patients who followed the protocol exactly, and 95% in all treated patients.
The data, to be shared at The Liver Meeting® 2025, highlight the regimen’s potential as a best-in-class, pan-genotypic, short-duration therapy. The FDC can be taken with or without food or common stomach acid blockers, and Phase 3 trials are already underway.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- November 7, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc announced the presentation of new modeling data predicting that the Company's combination regimen of bemnifosbuvir (BEM), a nucleotide analog polymerase inhibitor, and ruzasvir (RZR), an NS5A inhibitor, achieved near-complete inhibition of both viral replication and assembly and secretion into the bloodstream, with a modeled time to cure of approximately 7 to 8 weeks. T
AI Summary
Atea Pharmaceuticals reported new multiscale modeling data showing its oral combination of bemnifosbuvir (BEM) and ruzasvir (RZR) achieves near‑complete inhibition of both intracellular HCV replication and the assembly and secretion of new virus into the blood. The models predict a time to cure of about seven to eight weeks, driven by suppression at multiple stages of the viral life cycle.
These modeling results support the fixed‑dose combination (FDC) as a potentially short, convenient, best‑in‑class HCV therapy and reinforce Phase 2 outcomes in which an 8‑week regimen produced sustained virologic response rates (SVR12) of 98% in adherent patients and 95% overall. The data suggest the regimen could simplify treatment while maintaining high efficacy.
Atea also presented supporting analyses showing a high barrier to resistance and Phase 1 bioavailability results that allow dosing with or without food (and with famotidine). The FDC is being used in ongoing Phase 3 studies.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- October 7, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced that new data will be presented supporting the combination regimen of bemnifosbuvir, a nucleotide analog polymerase inhibitor and ruzasvir, an NS5A inhibitor, as a potential best-in-class regimen for the treatment of hepatitis C (HCV) infection at The Liver Meeting® 2025, the annual meeting of the American Association for the Study of Liver Diseases (AASLD).
AI Summary
Atea Pharmaceuticals announced that it will present new data on the combination of bemnifosbuvir, a nucleotide analog polymerase inhibitor, and ruzasvir, an NS5A inhibitor, as a potential best-in-class regimen for treating hepatitis C at The Liver Meeting® 2025 of the American Association for the Study of Liver Diseases (AASLD). Three abstracts have been accepted: two from a Phase 2 study covering multiscale HCV modeling and a viral resistance analysis, and one from a Phase 1 trial examining food effects on the fixed-dose combination.
Jean-Pierre Sommadossi, PhD, CEO of Atea, said the results support an optimized profile for patients and providers. With global Phase 3 enrollment already under way, he highlighted the regimen’s potential to reshape HCV care and increase cure rates.
The Liver Meeting 2025 will take place November 7–11 in Washington, DC, and abstracts will be available on the AASLD website after the October 7 embargo.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- June 24, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced that the first patient was dosed in the global Phase 3 C-FORWARD trial evaluating the combination regimen of bemnifosbuvir and ruzasvir compared to the regimen of sofosbuvir and velpatasvir for the treatment of hepatitis C virus (HCV).
AI Summary
Atea Pharmaceuticals recently marked a major milestone by dosing the first patient in its global Phase 3 C-FORWARD trial. This study is evaluating a new treatment combination for hepatitis C, pairing bemnifosbuvir with ruzasvir, and comparing it to the standard regimen of sofosbuvir and velpatasvir. The trial, conducted at sites outside North America, is part of Atea’s broader global HCV program. In the study, patients without cirrhosis will take the new regimen for 8 weeks, while those with compensated cirrhosis will receive it for 12 weeks. The goal is to assess whether this new treatment can provide a short, effective therapy with a lower risk of drug-drug interactions and greater convenience for both patients and healthcare providers. This approach could offer a more accessible way to cure hepatitis C in diverse populations around the world.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- May 7, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. today presented results from the full cohort of patients (n=275) enrolled in its Phase 2 study evaluating the once-daily combination of bemnifosbuvir (BEM), an oral nucleotide NS5B polymerase inhibitor, and ruzasvir (RZR), an oral NS5A inhibitor, for the treatment of hepatitis C virus (HCV).
AI Summary
Atea Pharmaceuticals today presented encouraging results from its Phase 2 study, which enrolled 275 patients with hepatitis C virus (HCV). The study evaluated a once-daily oral combination therapy of bemnifosbuvir (BEM), a nucleotide NS5B polymerase inhibitor, and ruzasvir (RZR), an NS5A inhibitor. Results showed that, after just 8 weeks of treatment, 98% of patients who followed the treatment plan achieved a sustained virologic response (SVR12), meaning the virus was not detectable 12 weeks after treatment ended. When all patients were considered, including those less adherent to the regimen, the response rate was 95%. The findings suggest that this short and convenient regimen could provide a strong treatment option for HCV, paving the way for further evaluation in Phase 3 trials.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- April 23, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced that the full results from the Phase 2 clinical study of Atea's regimen of bemnifosbuvir, a nucleotide analog polymerase inhibitor, and ruzasvir, an NS5A inhibitor, for the treatment of hepatitis C virus (HCV) infection will be presented at the European Association for the Study of the Liver (EASL) Congress 2025.
AI Summary
Atea Pharmaceuticals, Inc. announced that the full results from its Phase 2 clinical study of a hepatitis C treatment regimen will be presented at the European Association for the Study of the Liver (EASL) Congress 2025 in Amsterdam. The study examined a combination of bemnifosbuvir, a nucleotide analog polymerase inhibitor, and ruzasvir, an NS5A inhibitor, for HCV treatment. The presentation, scheduled for May 7–10, will showcase detailed findings on the regimen’s efficacy and safety, along with pharmacokinetic data supporting its promising profile. Notably, the trial met its primary endpoints, highlighting benefits such as a shorter treatment duration, minimal risk for drug-drug interactions, and convenience with no food effect. These results point to the potential of a best-in-class therapy designed to address the needs of patients with hepatitis C and improve treatment outcomes.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- April 9, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced that the first patient has been dosed in C-BEYOND, Atea's Phase 3 trial evaluating the regimen of bemnifosbuvir and ruzasvir for the treatment of adults with chronic hepatitis C virus (HCV).
AI Summary
Atea Pharmaceuticals, Inc. announced that the first patient has been dosed in its Phase 3 C-BEYOND trial. This trial is evaluating a new treatment regimen that combines bemnifosbuvir and ruzasvir for adults with chronic hepatitis C virus (HCV). The C-BEYOND trial is conducted in the US and Canada and is designed as an open-label study that compares this new regimen with the established sofosbuvir and velpatasvir treatment.
The new regimen aims to deliver benefits such as a shorter treatment duration—8 weeks for patients without cirrhosis and 12 weeks for those with compensated cirrhosis—a low risk of drug-drug interactions, and convenience with no food effect. Atea believes that if the regimen meets its goals, it could provide a best-in-class option to improve patient outcomes in the ongoing fight against HCV.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- March 19, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced the poster presentation of bemnifosbuvir preclinical data at the 38th International Conference on Antiviral Research (ICAR) 2025 taking place March 17-21, 2025 in Las Vegas, Nevada.
AI Summary
Atea Pharmaceuticals, Inc. announced that it will present preclinical data on bemnifosbuvir at the 38th International Conference on Antiviral Research (ICAR) 2025 in Las Vegas, Nevada, from March 17-21, 2025. The poster, titled “Metabolism of Bemnifosbuvir to its Active Triphosphate Metabolite AT-9010 is Cell-Line Dependent,” highlights the company’s extensive research in antiviral drug development. According to CEO Jean‑Pierre Sommadossi, the data demonstrate that the conversion of bemnifosbuvir, an oral prodrug used to target hepatitis C virus (HCV), into its active form depends greatly on the specific cell line being used. This finding underscores the necessity of choosing the right cell model when evaluating antiviral efficacy in vitro. The poster presentation, scheduled for specific times on March 18 and March 20, aims to offer valuable insights into how nucleotide prodrugs perform under varied cellular conditions.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- March 6, 2025
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. provided a business update.
AI Summary
Atea Pharmaceuticals, Inc provided a business update focusing on its next steps in the development of an HCV treatment regimen. The Company is moving ahead with its global Phase 3 program to evaluate the combination of bemnifosbuvir and ruzasvir. Patient enrollment for this trial is expected to start in April 2025, marking an important milestone in efforts to offer a shorter, 8‐week treatment option that minimizes drug interactions and improves convenience.
In its business update, Atea also announced key strategic initiatives. The Company has retained Evercore, an investment bank, to explore strategic partnerships related to the Phase 3 program. Additionally, Atea has taken steps to improve operational efficiency by reducing its workforce by approximately 25%, and it has enhanced its board by appointing a new independent director with extensive financial and strategic experience.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- December 4, 2024
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc announced that the Company's Phase 2 study of the regimen of bemnifosbuvir, a nucleotide analog polymerase inhibitor, and ruzasvir, an NS5A inhibitor, for treatment of hepatitis C virus (HCV) met its primary endpoints of safety and sustained virologic response at 12 weeks post-treatment (SVR12).
AI Summary
Atea Pharmaceuticals, Inc. announced positive results from its Phase 2 study examining an eight‐week treatment regimen for hepatitis C virus (HCV). The regimen combines bemnifosbuvir, a nucleotide analog polymerase inhibitor, and ruzasvir, an NS5A inhibitor. In the primary analysis, treatment-adherent patients achieved a 98% sustained virologic response at 12 weeks post-treatment (SVR12), demonstrating both strong safety and high efficacy.
The study showed that even when including patients with treatment non-adherence, the overall SVR12 rate was 95%, highlighting the regimen’s robust potency and forgiving profile. Importantly, the treatment was generally safe and well-tolerated, with no drug-related serious adverse events or discontinuations. These promising results set the stage for further clinical development and future discussions with regulatory experts to advance the treatment for HCV patients.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- December 4, 2024
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced that Global Phase 3 Program Initiation Expected Early in 2025
AI Summary
Atea Pharmaceuticals announced that it expects to initiate its global Phase 3 clinical program in early 2025. This next stage is designed to further evaluate the company's antiviral regimen for hepatitis C, which combines bemnifosbuvir and ruzasvir. The anticipated Phase 3 trial will focus on confirming the eight-week treatment's safety and efficacy, following promising results observed in Phase 2. Moreover, the new trial is expected to use a fixed dose combination tablet, reducing the daily pill count from four to two. This change aims to improve patient convenience and adherence while maintaining the regimen’s robust profile.
The company plans to discuss the Phase 3 program details with regulators, including the U.S. Food and Drug Administration (FDA), after the End of Phase 2 meeting. These plans highlight Atea Pharmaceuticals' commitment to addressing unmet needs in the hepatitis C market with a more convenient and efficient treatment option.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- September 13, 2024
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc. announced the outcome of the global Phase 3 SUNRISE-3 trial evaluating bemnifosbuvir, an oral nucleotide polymerase inhibitor, versus placebo for the treatment of COVID-19.
AI Summary
Atea Pharmaceuticals recently announced the results of its global Phase 3 SUNRISE-3 trial evaluating bemnifosbuvir, an oral nucleotide polymerase inhibitor, for treating COVID-19. The study, which involved 2,221 high-risk outpatients with mild to moderate COVID-19, compared bemnifosbuvir to a placebo when given alongside standard care. The trial did not meet its primary goal of achieving a statistically significant reduction in all-cause hospitalization or death through Day 29. Although the drug was generally safe and well tolerated, the evolving nature of COVID-19—with milder disease presentations and fewer hospitalizations—made it difficult for the antiviral to show a clear benefit.
Due to these factors, Atea Pharmaceuticals decided not to pursue a regulatory pathway for bemnifosbuvir in the treatment of COVID-19, despite the valuable learnings about the disease's progression in an ever-changing pandemic environment.
Read Announcement- Drug:
- Bemnifosbuvir
- Announced Date:
- August 28, 2024
- Indication:
- COVID-19
Announcement
Atea Pharmaceuticals, Inc announced that data highlighting the metabolic activation pathway of bemnifosbuvir were published in the peer-reviewed journal, PLOS Biology, in an article titled, "The activation cascade of the broad-spectrum antiviral bemnifosbuvir characterized at atomic resolution." Bemnifosbuvir, an oral nucleotide RNA-dependent RNA polymerase (RdRp) inhibitor, is in Phase 3 development for the treatment of COVID-19 and in Phase 2 development in combination with ruzasvir, an oral NS5A inhibitor, for the treatment of hepatitis c virus (HCV) infection.
AI Summary
Atea Pharmaceuticals announced that new research on bemnifosbuvir’s metabolic activation pathway was published in the peer-reviewed journal PLOS Biology. The study, titled “The activation cascade of the broad-spectrum antiviral bemnifosbuvir characterized at atomic resolution,” details how bemnifosbuvir (AT-527) is converted into its active form, AT-9010. The active metabolite selectively inhibits key RNA viral enzymes, effectively blocking RNA synthesis in both hepatitis C virus (HCV) and SARS‑CoV‑2 responsible for COVID-19. Bemnifosbuvir is currently in Phase 3 trials for COVID-19 and in Phase 2 trials for HCV in combination with ruzasvir, an NS5A inhibitor, highlighting its potential to treat multiple RNA viral infections. This detailed atomic resolution analysis adds to the growing scientific support for bemnifosbuvir’s antiviral activity and its further development as an effective oral antiviral therapy.
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