Interferon-free regimens containing setrobuvir for patients with genotype 1 chronic hepatitis C: a randomized, multicenter study.

Background & Aims: Setrobuvir is a direct-acting antiviral (DAA) non-nucleoside inhibitor of hepatitis C virus (HCV) polymerase. This study examined interferon-free combinations containing setrobuvir, a ritonavir-boosted protease inhibitor (danoprevir/r) and ribavirin, with/without the nucleoside inhibitor mericitabine in HCV genotype (G)1 patients. Methods: Non-cirrhotic treatment-naive patients (N = 110) were randomized to five groups. Three groups received a 14-day mericitabine/ribavirin lead-in followed by treatment with 3 DAAs (setrobuvir, danoprevir/r, mericitabine) plus ribavirin for 12 weeks (Group A: G1a; D: G1b) or 24 weeks (B: G1a), and two groups received 2 DAAs (setrobuvir, danoprevir/r) plus ribavirin for 12 weeks (E: G1b) or 24 weeks (C: G1a). Efficacy was defined as sustained virological response (HCV RNA < 25 IU/ml after 12 weeks' follow-up, SVR12). Results: Two groups met predefined futility criteria for breakthrough (C) or relapse (A) and were discontinued. SVR12 rates were 42.9% (3/7) and 74.1% (20/27) in G1a patients in Groups A and B, respectively, and 95.7% (22/23) and 68.2% (15/22) in G1b patients in Groups D and E respectively. All G1a patients assigned to 24 weeks of treatment who experienced a decrease in HCV RNA of >= 2.3 log(10) IU by the end of the lead-in period (n = 28) achieved SVR12. Overall, treatment was well tolerated and most adverse events were mild to moderate. No major safety signals were identified. Conclusions: An interferon-free setrobuvir-based regimen (3 DAAs plus ribavirin) is safe and effective in treatment-naive G1 patients.