Enanta Pharmaceuticals, Inc. announced results from AbbVie’s Phase 3 CERTAIN-1 study of 8 weeks of treatment with AbbVie’s investigational, pan-genotypic, ribavirin (RBV)-free regimen of glecaprevir (ABT-493)/pibrentasvir (ABT-530) (G/P) in Japanese patients with genotype 1 (GT1) chronic hepatitis C virus (HCV) infection without cirrhosis. Top-line results from the study demonstrated 99% (n=105/106) of patients without cirrhosis, who represent the majority of HCV patients, and without the Y93H variant, achieved sustained virologic response at 12 weeks after treatment (SVR12). The one patient who did not reach SVR12 in this intent to treat (ITT) population was lost to follow-up. All 23 patients with the Y93H variant were assigned to the G/P arm of this comparator study, and 100% achieved SVR12. These data are the first to be released by AbbVie from registrational studies in Japan as part of its global G/P clinical development program, designed to investigate a faster path to virologic cure for all major HCV genotypes and with the goal of addressing treatment areas of continued unmet need. The results demonstrated from the CERTAIN-1 study are consistent with recently announced 8-week, GT1 data from AbbVie’s global registration studies of G/P. Approximately 1 million people are living with hepatitis C in Japan, with 60% to 70% of those infected with GT1 chronic HCV.1,3 Patients participating in the CERTAIN-1 study were further representative of the HCV-infected patient population in Japan, where the prevalence of HCV infection increases with age, because a majority of patients in the study were over 65 years of age. The CERTAIN-1 study compared the safety and efficacy of 8 weeks of treatment with the investigational G/P regimen to 12 weeks of treatment with ombitasvir/paritaprevir/ritonavir (OBV/PTV/r), in GT1 chronic HCV-infected patients. The primary endpoint of the study was met, as 8 weeks of G/P was shown to be non-inferior to 12 weeks of OBV/PTV/r (100% SVR12; n=52). Additionally, in sub-study 1 evaluating GT1 patients (treated with G/P) without cirrhosis and who were new to treatment with direct-acting antivirals (DAA), no patients discontinued treatment due to adverse events (AEs). In patients treated with OBV/PTV/r, there was one who discontinued treatment due to AEs. In patients receiving the G/P regimen, the most common AEs, occurring at a rate greater than 5%, were nasopharyngitis (inflammation of the throat and nasal passages) and pruritus (itchiness).