Efficacy and safety of simeprevir with PegIFN/ribavirin in naïve or experienced patients infected with chronic HCV genotype 4

Background & aims: Simeprevir (SMV) is a once-daily (QD), oral hepatitis C virus (HCV) NS3/4A protease inhibitor approved for treatment of genotype (GT) 1 and GT4 infection. This Phase III, open-label, single-arm study (RESTORE; NCT01567735) evaluated efficacy/safety of SMV with peginterferon-α-2a/ribavirin (PR) in patients with chronic HCV GT4 infection.

Methods: 107 patients were included. Treatment-naïve (n=35) and prior relapse patients (n=22) received SMV 150mg QD+PR (12 weeks), followed by PR alone (12 or 36 weeks, response-guided [HCV RNA <25IU/ml detectable/undetectable at week 4 and <25IU/ml undetectable at week 12]). Prior non-responders (partial, n=10; null, n=40) received SMV/PR (12 weeks), followed by PR for 36 weeks. The primary endpoint was sustained virologic response 12 weeks after end of treatment (SVR12).

Results: Median age: 49.0years; 28.0% Black/African; 7.5% IL28B CC; 28.8% METAVIR F4. Overall, 65.4% (70/107) of patients achieved SVR12 (82.9% [29/35] treatment-naïve; 86.4% [19/22] prior relapsers; 60.0% [6/10] prior partial responders; 40.0% [16/40] prior null responders). In treatment-naïve and prior relapser patients fulfilling response-guided criteria for 24 weeks of treatment (88.6% [31/35] and 90.9% [20/22]), SVR12 rates were high: 93.5% [29/31] and 95.0% [19/20], respectively. Overall on-treatment failure and relapse rates were 23.4% (25/107) and 14.6% (12/82), respectively. Adverse events (AEs) were mainly grade 1/2; serious AEs were infrequent (4.7%) and considered unrelated to SMV.

Conclusions: Efficacy and safety of SMV 150mg QD for 12 weeks with PR in treatment-naïve or -experienced patients with chronic HCV GT4 infection were in line with previous reports for HCV GT1 infection.