Atea Pharmaceuticals Advances HCV and HEV Programs, Expects Key Data in 2026

Atea Pharmaceuticals (AVIR) is on track to deliver top-line Phase 3 results for its hepatitis C virus (HCV) program in mid-2026, with a second readout expected by year-conclude. The company is also making significant progress in developing a novel treatment for chronic hepatitis E virus (HEV) infection, anticipating a first-in-human study in mid-2026. As of December 31, 2025, Atea held $301.8 million in cash and investments, sufficient to fund operations through 2027.

HCV Program Progress

Atea’s global Phase 3 program for HCV is evaluating a regimen of bemifovir and rizatrizumab. The C BEYOND trial, conducted in North America, has completed enrollment with over 880 patients. Enrollment in the C FORWARD trial, outside of North America, is expected to be completed by mid-2026. Both trials are open-label, randomized, and designed to align with regulatory requirements from the FDA and EMA. Source

Phase 2 data demonstrated a high barrier to resistance and a 98% sustained virologic response rate (SVR12) in the per-protocol population, and 95% in the efficacy-evaluable group, with an eight-week treatment duration. The regimen also showed a low risk of drug-drug interactions, including with proton pump inhibitors, H2 blockers, and HIV therapy, and does not require dietary restrictions. Source

Commercial Strategy for HCV

Atea is preparing for a commercial launch of its HCV regimen, targeting the concentrated U.S. Prescriber base, where approximately 6,000 providers write 80% of direct-acting antiviral (DAA) prescriptions. The company plans to utilize a 75-person sales force. Market research indicates that physicians intend to prescribe the regimen to approximately half of their patients, regardless of cirrhosis status, and payers have responded favorably to potential formulary inclusion. Source

Expanding into Hepatitis E

In November 2025, Atea expanded its antiviral pipeline to address chronic hepatitis E, a liver disease with no currently approved therapies. The company has initiated Investigational New Drug (IND)- and Clinical Trial Application (CTA)-enabling studies for its lead HEV candidate, AT-587, and anticipates a first-in-human study in mid-2026. Source

Approximately 3% of the 450,000 immunocompromised patients in the U.S. And Europe are at risk for chronic HEV annually, representing a potential market opportunity of $750 million to $1 billion per year. Source

Financial Position

As of December 31, 2025, Atea reported $301.8 million in cash, cash equivalents, and marketable securities, providing a financial runway through 2027. The company completed a $25 million share repurchase program in 2025, retiring 7.6 million shares. Source

Key Takeaways

• Phase 3 HCV trials (C BEYOND and C FORWARD) are on track for data readouts in mid-2026 and year-end 2026, respectively.
• Atea is developing a novel treatment for chronic hepatitis E, with a first-in-human study planned for mid-2026.
• The company has a strong cash position, sufficient to fund operations through 2027.
• Market research suggests strong potential for commercial uptake of the HCV regimen.