Efficacy and safety of 12 weeks of elbasvir ± grazoprevir ± ribavirin in participants with hepatitis C virus genotype 2, 4, 5 or 6 infection: The C-SCAPE study

People with hepatitis C virus (HCV) infection other than genotype 1 represent a heterogeneous group. The aim of the phase 2 C-SCAPE study was to evaluate elbasvir/grazoprevir (EBR/GZR), with or without ribavirin (RBV), in participants with HCV genotype 2, 4, 5 or 6 infection. This was a part randomised, open-label, parallel-group study (NCT01932762; PN047-03) of treatment-naive, noncirrhotic participants. Participants with HCV genotype 2 infection received GZR 100 mg + RBV ± EBR 50 mg for 12 weeks and those with genotype 4, 5 or 6 infection were randomized to receive EBR/GZR ± RBV for 12 weeks. The primary endpoint was sustained virological response 12 weeks after completion of treatment (SVR12; HCV RNA <25 IU/mL). Among participants with genotype 2 infection, SVR12 was achieved by 80% (24/30) of those receiving EBR/GZR + RBV and 73% (19/26) of those receiving GZR + RBV. SVR rates were high in participants with HCV genotype 4 infection receiving EBR/GZR with and without RBV (100% [10/10] and 90% [9/10]; respectively). In contrast, the addition of RBV to EBR/GZR appeared to increase SVR12 in participants with genotype 5 infection (EBR/GZR, 25%; EBR/GZR + RBV 100% [4/4]). In participants with genotype 6 infection, SVR12 was 75% (3/4) in both those receiving EBR/GZR and those receiving EBR/GZR + RBV. The safety profile was similar across treatment arms, with adverse events tending to occur more frequently among participants receiving RBV. In conclusion, these data support the inclusion of participants with genotype 4 or 6 infection in the EBR/GZR phase 3 studies. EBR/GZR ± RBV was unsatisfactory for participants with genotype 2 or 5 infection.