Exploratory trial of ombitasvir and ABT-450/r with or without ribavirin for HCV genotype 1, 2, and 3 infection

Objectives: To examine the safety and efficacy of ombitasvir and ABT-450 with ritonavir (ABT-450/r)±ribavirin (RBV) in treatment-naïve, non-cirrhotic adults with chronic HCV genotype 1-3 infection. Methods: Patients in this open-label, exploratory, phase 2, multicenter study received ombitasvir (25mg QD) and ABT-450/r (200/100mg QD)±RBV for 12 weeks. Primary efficacy endpoint was HCV RNA<lower limit of quantitation (LLOQ) from week 4 through 12. Sustained virologic response 12 weeks post-treatment (SVR₁₂) was a secondary endpoint. Results: Sixty-one patients were enrolled. Among genotype 1-, 2-, and 3-infected patients, respectively, HCV RNA was<LLOQ from week 4 through 12 in 10 (100%; 95% CI 69-100), 9 (90%; 56-100), and 7 (70%; 35-93) receiving the RBV-containing regimen and 9 (90%; 56-100), 8 (80%; 44-97), and 2 (18%; 2-52) receiving the RBV-free regimen. Among genotype 1-, 2-, and 3-infected patients, respectively, SVR₁₂ was achieved by 10 (100%), 8 (80%), and 5 (50%) receiving the RBV-containing regimen, and 6 (60%), 6 (60%), and 1 (9%) receiving the RBV-free regimen. The most common adverse events were fatigue, nausea, and headache. One patient discontinued due to an adverse event. Conclusions: In this study, ombitasvir and ABT-450/r±RBV regimens were generally well-tolerated. Sustained virologic response was achieved in most patients with HCV genotype 1 or 2 infection, but low SVR rates were observed in HCV genotype 3-infected patients.