Efficacy and safety of ledipasvir/sofosbuvir with and without ribavirin in patients with chronic HCV genotype 1 infection receiving opioid substitution therapy: Analysis of phase 3 ION trials

Background. Interferon-based hepatitis C virus (HCV) therapy is safe and effective among people receiving opioid substitution therapy (OST), but treatment uptake remains low. Our aim was to evaluate the impact of OST and drug use during therapy on completion, adherence, sustained virologic response (SVR12), and safety of ledipasvir/sofosbuvir ± ribavirin. Methods. The phase 3 ION studies evaluated a fixed-dose combination of ledipasvir/sofosbuvir ± ribavirin administered for 8, 12, or 24 weeks in patients with chronic HCV genotype 1. People with clinically significant drug use ( prior 12 months) or noncannabinoids detected at screening by urine drug tests (not explained by prescriptions) were ineligible. Stored samples were available from ION-1 for retrospective testing for illicit drugs by enzyme-linked immunosorbent assay. Results. Among 1952 patients enrolled in the ION studies, 4% (n = 70) were receiving OST. Among those receiving (n = 70) and not receiving OST (n = 1882), there was no difference in treatment completion (97% vs 98%; P =.40), ≥80% adherence (93% vs 92%; P = 1.00), SVR12 (94% vs 97%; P = .28), and serious adverse events (4% vs 3%; P = .43), respectively. Among participants in the ION-1 trial, 23% (n = 196) used illicit drugs during therapy (15% cannabinoids alone; 8% other illicit drugs ± cannabinoids). There was no difference in treatment completion, ≥80% adherence, SVR12, or serious AEs in those with no drug use during treatment compared with those who used cannabinoids and/or other illicit drugs. No cases of HCV reinfection were observed in the 24 weeks following treatment. Conclusions. OST and drug use during HCV therapy did not impact treatment completion, adherence, SVR12, or safety.