Grazoprevir and elbasvir plus ribavirin for chronic HCV genotype-1 infection after failure of combination therapy containing a direct-acting antiviral agent

Xavier Forns, Stuart C. Gordon, Eli Zuckerman, Eric Lawitz, Jose L. Calleja, Harald Hofer, Christopher Gilbert, John Palcza, Anita Y.M. Howe, Mark J. DiNubile, Michael N. Robertson, Janice Wahl, Eliav Barr, Maria Buti

The Phase-2 C-SALVAGE study evaluated an investigational interferon-free combination of grazoprevir (a NS3/4A protease inhibitor) and elbasvir (a NS5A inhibitor) with ribavirin for patients with chronic HCV genotype-1 infection who had failed licensed DAA-containing therapy. C-SALVAGE was an open-label study of grazoprevir 100 mg/elbasvir 50 mg QD with weight-based ribavirin BID for 12 weeks in cirrhotic and non-cirrhotic patients with chronic HCV genotype-1 infection who had not attained SVR after ⩾4 weeks of peginterferon and ribavirin plus either boceprevir, telaprevir, or simeprevir. Exclusion criteria included decompensated liver disease, hepatocellular carcinoma, and HIV or HBV co-infection. The primary efficacy outcome was SVR12 defined as a HCV RNA level below the assay limit of quantification 12 weeks after the end of treatment. Of the 79 patients treated with ⩾1 dose of study drug, 66 (84%) patients had a history of virologic failure on a regimen containing a NS3/4A protease inhibitor; 12 of the other 13 patients discontinued prior treatment because of adverse experiences. At entry, 34 (43.6%) of 78 evaluable patients harbored NS3 RAVs. SVR12 rates were 76/79 (96.2%) overall, including 28/30 (93.3%) patients with genotype 1a infection, 63/66 (95.5%) patients with prior virologic failure, 43/43 (100%) patients without baseline RAVs, 31/34 (91.2%) patients with baseline NS3 RAVs, 6/8 (75.0%) patients with baseline NS5A RAVs, 4/6 (66.7%) patients with both baseline NS3 and RAVs, and 32/34 (94.1%) cirrhotic patients. None of the 5 reported serious adverse events were considered drug-related. Grazoprevir/elbasvir plus ribavirin for 12 weeks provides a promising new treatment option for patients after failure of triple therapy containing an earlier-generation protease inhibitor.