Ombitasvir/paritaprevir/ritonavir and dasabuvir with or without sofosbuvir for patients with hepatitis C virus genotype 1 infection who failed a prior course of direct-acting antiviral therapy

Introduction: Despite high efficacy of current direct-acting antiviral agents (DAAs) in treating chronic hepatitis C virus (HCV) infection, a small portion of patients fail treatment. QUARTZ-I was a phase 2, open-label, multicenter, two-part study that assessed the safety and efficacy of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) with dasabuvir (DSV) with or without the addition of sofosbuvir (SOF) and/or ribavirin (RBV) in DAA treatment-experienced adults with chronic HCV GT1 infection. Materials and Methods: Genotype 1 HCV-infected patients with or without compensated cirrhosis had prior treatment failure to any DAA (part 1) or ledipasvir/SOF (part 2). Patients received OBV/PTV/r + DSV ± SOF with or without RBV for 12 or 24 weeks. The primary endpoint of this study is the percentage of patients achieving sustained virologic response at post-treatment week 12 (SVR12). Results: In part 1 of the study, 95.5% (21/22) of patients achieved SVR12, and in part 2, the SVR12 rate was 85.7% (6/7). Most adverse events (AEs) were mild and moderate in severity. Two serious AEs occurred and were assessed as not being related to study drug, of which one resulted in study drug discontinuation. Two patients experienced grade 3 elevations of serum alanine aminotransferase, and no other grade ≥3 laboratory abnormalities were observed. Conclusion: The multi-targeted regimen of OBV/PTV/r + DSV ± SOF with or without RBV was effective in the treatment of patients who failed previous DAA regimens including NS3/4A protease and NS5A and NS5B polymerase inhibitors. These results provide a promising outcome for patients that traditionally had limited treatment options.