Retreatment with elbasvir, grazoprevir, sofosbuvir ± ribavirin is effective for GT3 and GT1/4/6 HCV infection after relapse

INTRODUCTION: Despite highly effective direct-acting antiviral (DAA) therapies for chronic hepatitis C virus (HCV) infection, some patients experience virological relapse. Salvage regimens should include multiple agents to suppress emergence of resistance-associated substitutions (RAS) and minimise treatment failure. The combination of sofosbuvir (SOF) and elbasvir/grazoprevir (ELB/GZR) ±ribavirin (RBV) is an effective retreatment strategy for HCV genotype (GT)1 and 4 infection. We hypothesised that SOF and ELB/GZR (±RBV) would also be an effective salvage regimen for DAA-experienced GT3 patients. METHODS: We evaluated the efficacy and safety of SOF/ELB/GZR ± RBV in DAA-experienced participants with chronic HCV infection who had prior relapse. Participants were treated at four hospitals between December 2016 and March 2018 for either 12- or 16-weeks. The primary endpoint was sustained virological response at week 12 post-treatment (SVR12) using intention-to-treat analysis. RESULTS: There were 40 participants included in the analysis. The mean age was 53 years, 53% had GT3, 33% had GT1 infection and 63% had cirrhosis. Fifty-eight percent were treated for 12 weeks, 42% were treated for 16 weeks and 90% received RBV. The SVR12 rate was 98% overall, 100% in non-GT3 participants and 95% in GT3 participants. One GT3 cirrhotic participant relapsed. ELB/GZR was stopped at week 6 in one GT3 cirrhotic participant who switched to SOF/velpatasvir/RBV for a further 12 weeks and achieved SVR12. RBV dose reduction was required in two participants. Treatment was otherwise well tolerated. DISCUSSION: The combination of SOF/ELB/GZR ± RBV is effective and safe for difficult-to-cure patients who relapse after first-line DAA, including those with cirrhosis and GT3 infection.