de Lédinghen V, et al. - This prospective and randomized study was designed to assess the efficacy (primary endpoint: sustained virological response (SVR) 12 weeks after end of treatment [SVR12]) and safety of sofosbuvir + grazoprevir/elbasvir + ribavirin for 16 or 24 weeks in patients who had failed to achieve SVR on previous NS5A- or NS3-based therapy and with evidence of resistance-associated substitutions (RASs) at failure. Findings here supported the concept of retreating with sofosbuvir + grazoprevir/elbasvir + ribavirin, for 16 weeks, genotype 1 or 4 DAA-experienced patients with proven NS5A or NS3 RASs.