Retreatment of patients with treatment failure of directacting antivirals: Focus on hepatitis C virus genotype 1b

The recent development of direct-acting antiviral agents(DAAs) against hepatitis C virus(HCV) infection could lead to higher sustained virological response(SVR) rates, with shorter treatment durations and fewer adverse events compared with regimens that include interferon. However, a relatively small proportion of patients cannot achieve SVR in the first treatment, including DAAs with or without peginterferon and/or ribavirin. Although retreatment with a combination of DAAs should be conducted for these patients, it is more difficult to achieve SVR when retreating these patients because of resistance-associated substitutions(RASs) or treatment-emergent substitutions. In Japan, HCV genotype 1 b(GT1 b) is founded in 70% of HCVinfected individuals. In this minireview, we summarize the retreatment regimens and their SVR rates for HCV GT1 b. It is important to avoid drugs that target the regions targeted by initial drugs, but next-generation combinations of DAAs, such as sofosbuvir/velpatasvir/voxilaprevir for 12 wk or glecaprevir/pibrentasvir for 12 wk, are proposed to be potential solution for the HCV GT1 b-infected patients with treatment failure, mainly on a basis of targeting distinctive regions. Clinicians should follow the new information and resources for DAAs and select the proper combination of DAAs for the retreatment of HCV GT1 b-infected patients with treatment failure.