Among prior relapsers, 76% (218/286) achieved an eRVR and of those 95% (208/218) achieved an SVR. In an earlier, dose-finding clinical trial, 78% (52/67) of prior relapsers achieved an eRVR and were treated with 24 weeks of peginterferon alfa and ribavirin (T12/PR24); of those 94% (49/52) achieved an SVR.

For all populations in the study (prior relapsers, prior partial responders, and prior null responders), SVR rates were higher for the T12/PR group than for the Pbo/PR48 group across subgroups by sex, age, ethnicity, body mass index, HCV genotype subtype, baseline HCV-RNA level, and extent of liver fibrosis.

Twenty-three percent of INCIVEK-treated subjects had cirrhosis at baseline. SVR rates among cirrhotic subjects who received INCIVEK combination treatment compared to Pbo/PR48 were: 87% (48/55) compared to 13% (2/15) for prior relapsers, 34% (11/32) compared to 20% (1/5) for prior partial responders, and 14% (7/50) compared to 10% (1/10) for prior null responders.

Four percent (19/530) of treatment experienced subjects who received INCIVEK combination treatment were Black/African Americans; the SVR rate for these subjects was 63% (12/19) compared to 65% (328/503) for Caucasians.