Retreatment With Sofosbuvir and Simeprevir of Patients With Hepatitis C Virus Genotype 1 or 4 Who Previously Failed a Daclatasvir-Containing Regimen

Failure to achieve sustained virological response (SVR) with hepatitis C virus (HCV) direct-acting antiviral-based regimens is commonly associated with emergence of resistance-associated variants (RAVs). To avoid cross-resistance, recent guidelines recommend that patients who have failed on nonstructural protein 5A (NS5A) inhibitors should be retreated with sofosbuvir (SOF; NS5B inhibitor) combined with simeprevir (SIM; protease inhibitor [PI]); however, supporting evidence is lacking. This "real-world" study comprised patients who had failed to achieve SVR on previous NS5A-based therapy with daclatasvir (DCV) plus pegylated interferon (Peg-IFN) and ribavirin (RBV), with (n = 3) or without (n = 13) asunaprevir (ASV; PI). All 16 patients were retreated for 12 weeks with SOF plus SIM, without RBV. Antiviral efficacy was evaluated using the primary endpoint of SVR12 (SVR 12 weeks post-treatment); on-treatment response was also assessed. Patients (N = 16; 13 male; mean age: 54 years [range, 43-73]) were chronically infected with HCV genotype (GT) 1 (1a, n = 11; 1b, n = 3) or 4 (n = 2); they had advanced fibrosis or compensated cirrhosis (FibroScan, 9.6-70 kPa; cirrhosis, n = 9); median baseline HCV-RNA level was 1.38 x 10(6) IU/mL. No patient discontinued treatment because of adverse events or virological failure. All patients achieved HCV RNA below lower limit of quantification (<12 IU/mL) by end of treatment (EOT) and 10 of 16 had a rapid response (week 4). SVR12 was achieved by 14 of 16 patients; the remaining 2 relapsed by 4 weeks post-EOT (both were GT 1a infected with cirrhosis; 1 had previously failed DCV-ASV plus Peg-IFN and RBV). Presence of SIM RAVs/polymorphisms (R155K and Q80K) at study baseline did not predict retreatment failure. Conclusion: Our findings support the concept of retreating NS5A inhibitor failures with SOF combined with SIM. However, the most difficult-to-cure patients may need more than 12 weeks of treatment and/or the addition of RBV.