In the mITT analysis (n=905, cirrhotic and non-cirrhotic), BEM/RZR achieved a 93.9% sustained virologic response (SVR) rate vs. 94.8% for SOF/VEL (Epclusa) at Week 24, encompassing SVR at 12 weeks post-treatment (accepted definition of cure for HCV) in both arms. These results achieved the primary endpoint of statistical non-inferiority, with a 95% confidence interval for difference in SVR rates within the prespecified 5% margin. The mITT analysis in patients without cirrhosis (n=721) showed BEM/RZR (8 weeks of treatment) achieved a 93.5% SVR rate vs. 94.6% for SOF/VEL (12 weeks of treatment). In patients with cirrhosis (12 weeks treatment in both arms) (n=184), BEM/RZR achieved a 95.4% SVR rate vs. 95.4% for SOF/VEL. In C-BEYOND, rates of virologic failure across all populations were low and comparable between treatment arms. Statistical non-inferiority was also met in secondary endpoints, including the per-protocol analysis.

BEM/RZR was administered as an 8-week regimen to patients without cirrhosis compared with the 12-week regimen of SOF/VEL, highlighting the potential of BEM/RZR to deliver robust antiviral efficacy with a shorter treatment duration. In the US, approximately 80-90% of people living with HCV do not have cirrhosis. Together with its potential advantages of a shorter treatment duration for most patients, low risk of drug-drug interactions and no food effect, the results from C-BEYOND further reinforce BEM/RZR’s potential as a differentiated, best-in-class treatment option for people with HCV.

In C-BEYOND, BEM/RZR demonstrated robust SVR rates across HCV genotypes that predominate in North America. C-FORWARD, which is being conducted outside North America, includes a broader range of HCV genotypes and is expected to provide additional efficacy data in genotypes more frequently found outside the US and Canada. In C-BEYOND, BEM/RZR was generally safe and well tolerated with no drug-related serious adverse events or drug related early treatment discontinuations. Safety was comparable between treatment arms.  

C-BEYOND was conducted at approximately 120 sites in the US and Canada. C-FORWARD, which is fully enrolled with more than 880 patients, is being conducted at approximately 120 sites in 17 countries outside North America and is on track to report topline results in early 2027. Atea plans to present the detailed results of its global Phase 3 program in HCV at future medical conferences and submit to peer-reviewed medical journals for publication.