Purpose / DescriptionIn this open-label, phase 2 trial involving patients with genotype 1 hepatitis C, treatment-naïve patients with compensated cirrhosis (cohort 1, n=123) and treatment-experienced patients with a prior null response to peginterferon plus ribavirin (cohort 2, n=130) were randomized to receive elbasvir plus grazoprevir, with or without ribavirin, for 12 or 18 weeks. In the cirrhotic cohort, 90% to 97% of patients achieved an SVR12; in the null responder cohort, SVR12 occurred in 91% to 100% of patients. The SVR12 rate for null cirrhotics (historically the most treatment refractory) was 94% for genotype 1a and 100% for genotype 1b. A subgroup analysis did not show a significant benefit of adding ribavirin to elbasvir plus grazoprevir.