de Lédinghen V, et al. - This prospective and randomized study was performed to assess the efficacy and safety of sofosbuvir + grazoprevir/elbasvir + ribavirin for 16 or 24 weeks in patients who had failed to achieve sustained virological response (SVR) on previous NS5A or NS3-based therapy and with evidence of resistance-associated substitutions (RAS) at failure. Findings supported the concept of retreating with sofosbuvir+ grazoprevir/elbasvir + ribavirin for 16 weeks GT1 or GT4 DAA-experienced patients with proven NS5A or NS3 RAS.