Atea’s bemnifosbuvir and ruzasvir (BEM/RZR) achieved statistical non-inferiority to Epclusa in the Phase 3 C-BEYOND trial, supporting an 8-week treatment option for chronic hepatitis C.
Written By: Anamika Koshti, PharmD
Reviewed By: Pharmacally Editorial Team
On July 28, 2026, Atea Pharmaceuticals, Inc. announced positive topline results from C-BEYOND (NCT06868264), the pivotal Phase 3 trial of the fixed-dose combination of bemnifosbuvir and ruzasvir (BEM/RZR) conducted across approximately 120 sites in the United States and Canada. BEM/RZR achieved statistical non-inferiority to sofosbuvir/velpatasvir (SOF/VEL; Epclusa), the current standard of care, marking the first-ever successful head-to-head trial in a global Phase 3 hepatitis C virus (HCV) program. Both primary and secondary endpoints were met.
HCV: A Persistent Public Health Challenge
HCV is a blood-borne RNA virus that primarily infects liver cells and is a leading cause of chronic liver disease, liver transplants, and liver cancer in the US, Europe, and Japan. Approximately 50 million people worldwide live with chronic HCV, including up to 4 million in the US, where new diagnoses continue to outpace annual cures and approximately 240,000 HCV-related deaths occur each year globally. In the US, roughly 80% to 90% of people living with HCV do not have cirrhosis, and approximately 80% take multiple concomitant medications for comorbidities such as hypertension, heart arrhythmia, and GERD, raising the potential for drug-drug interactions with current therapies.
What Are Bemnifosbuvir and Ruzasvir?
BEM is a nucleotide analog polymerase inhibitor approximately 10-fold more active than sofosbuvir (SOF) against HCV genotypes 1 to 5 in vitro, retaining full activity against the SOF resistance-associated substitution (S282T) with up to 58-fold greater potency. RZR is an NS5A inhibitor with pan-genotypic antiviral activity. Both support once-daily dosing and have been well-tolerated across thousands of subjects in prior studies.
C-BEYOND Trial Design
C-BEYOND is a Phase 3, open-label, controlled trial of 905 treatment-naïve patients with chronic HCV with and without compensated cirrhosis, analysed in the modified intent-to-treat (mITT) population, the FDA-agreed primary analysis. BEM/RZR was given once daily for 8 weeks (non-cirrhotic, n=721) or 12 weeks (cirrhotic, n=184), versus SOF/VEL once daily for 12 weeks in all patients. The primary endpoint was HCV RNA below the LLOQ at 24 weeks from treatment start, encompassing SVR12, with the 24-week measurement ensuring a consistent relative timepoint across both arms given their differing treatment durations.
Primary and Secondary Endpoint Results
In the mITT analysis (n=905), BEM/RZR achieved an SVR rate of 93.9% compared to 94.8% for SOF/VEL. The 95% confidence interval for the difference in SVR rates was within the prespecified 5% non-inferiority margin, confirming statistical non-inferiority for the primary endpoint. Subgroup results by cirrhosis status were:
- Non-cirrhotic patients (BEM/RZR 8 weeks vs SOF/VEL 12 weeks, n=721): BEM/RZR 93.5% SVR vs SOF/VEL 94.6% SVR.
- Cirrhotic patients (both arms 12 weeks, n=184): BEM/RZR 95.4% SVR vs SOF/VEL 95.4% SVR.
Rates of virologic failure across all populations were low and comparable between arms. Statistical non-inferiority was also met in secondary endpoints, including the per-protocol analysis. BEM/RZR demonstrated robust SVR rates across HCV genotypes that predominate in North America.
Safety
BEM/RZR was generally safe and well tolerated throughout C-BEYOND. No drug-related serious adverse events were reported, and there were no drug-related early treatment discontinuations. Safety was comparable between the BEM/RZR and SOF/VEL treatment arms.
What Makes BEM/RZR Differentiated?
For the approximately 80% to 90% of US HCV patients without cirrhosis, BEM/RZR’s 8-week treatment course is 4 weeks shorter than the 12-week SOF/VEL regimen. Additional advantages include a low drug-drug interaction risk and no food effect. Atea’s second Phase 3 trial, C-FORWARD (NCT07037277), is underway at approximately 120 sites in 17 countries outside North America with over 880 patients enrolled, covering a broader range of HCV genotypes. Topline results are expected in early 2027.
What This Means?
A shorter regimen with comparable cure rates to the current standard has direct implications for HCV elimination. Lower drug-drug interaction risk and a shorter duration are particularly relevant for the many HCV patients managing multiple conditions and taking several daily medications. Subject to C-FORWARD results and regulatory review, BEM/RZR could offer a differentiated treatment option in this setting.
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About the Writer
Anamika Koshti (LinkedIn) is a PharmD professional and healthcare writer with interests in clinical research, pharmacovigilance, and evidence-based medicine. She has authored peer-reviewed publications on Alzheimer’s disease and PCOS, presented research at national conferences, and gained hands-on experience in medical content development and clinical data interpretation. She is committed to translating complex medical research into accurate, accessible content for healthcare professionals and patients.