PE-048: ONYX-II: Efficacy of Ombitasvir/Paritaprevir/Ritonavir + Dasabuvir + Ribavirin in HCV Genotype 1b-Infected Patients with Compensated Cirrhosis from South Korea and Taiwan

Background: Chronic hepatitis C virus (HCV) infection is associated with development of complications including hepatocellular carcinoma, liver failure and cirrhosis. Patients with cirrhosis are historically more difficult to cure. In southeastern Asia, the most prevalent HCV genotype (GT) is GT1b. In western populations, the 3 direct-acting antiviral (3-DAA) regimen of ombitasvir (OBV), ritonavir-boosted paritaprevir (PTV/r; identified by AbbVie and Enanta) and dasabuvir (DSV) ± ribavirin (RBV) demonstrated sustained virologic response (SVR) at post-treatment week 12 (SVR12) rates of 99% in patients with GT1b infection and compensated cirrhosis regardless of prior treatment experience. The regimen, however, has not been investigated in southeastern Asian populations. The ONYX-II study is evaluating the efficacy and safety of this regimen in Asian patients with HCV GT1b infection and compensated cirrhosis. Methods: Treatment-naive and interferon-based therapy-experienced patients with HCV GT1b-infection and compensated cirrhosis were enrolled in South Korea, Taiwan, and China, and received 12 weeks of OBV/PTV/r (25 mg/150 mg/100 mg once daily) and DSV (250 mg twice daily) with RBV (weight-based). Patients will be followed for 48 weeks after the last dose of study drugs. The primary objectives are to compare the SVR12 rate to the known SVR rate of telaprevir + peg-interferon (IFN) + RBV therapy, and to assess the safety of OBV/PTV/r + DSV + RBV. Results: Twenty-one and 20 subjects were enrolled in South Korea and Taiwan, respectively. Of South Korean patients, 52% were male and 71% were treatment-experienced; of Taiwanese patients, 45% were male and 65% were treatment-experienced. Safety data and SVR at post-treatment week 4 (SVR4) will be available for presentation. Conclusions: The ONYX-II study evaluates the 3-DAA regimen of OBV/PTV/r + DSV with RBV for Asian patients with compensated cirrhosis and HCV GT1b infection. Resultant data may provide evidence for treatment guidelines for HCV GT1b in this population.