Paritaprevir, ritonavir, ombitasvir, and dasabuvir with and without ribavirin in people with HCV genotype 1 and recent injecting drug use or receiving opioid substitution therapy

Background: Direct-acting antiviral therapy for hepatitis C virus (HCV) infection is safe and effective, but there are little data among people who have recently injected drugs. This study evaluated the efficacy, and safety of paritaprevir/ritonavir, ombitasvir, dasabuvir with or without ribavirin for chronic HCV genotype (G) 1 among people with recent injecting drug use and/or receiving OST. Methods: D3FEAT is an international open-label study that recruited treatment-naive participants with recent injecting drug use (previous 6 months) and/or receiving OST with chronic HCV G1 infection between June 2016 and February 2017 in seven countries. Participants received paritaprevir/ritonavir, ombitasvir, dasabuvir with (Gla) or without ribavirin (Gib) administered twice daily in a one-week electronic blister pack (records timing of each dose) for 12 weeks. The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (SVR12). Results: Among 87 participants (median age 48 years), 23% were female, 8% had cirrhosis, and 90% had Gla. Overall, 71% were receiving OST, 61% injected in the previous six months, 45% injected in the previous month, and 15% injected > daily. Treatment completion was 97% (84 of 87). There were no virological breakthroughs, but three discontinuations (loss to follow-up, n = 1; non-adherence, n = 1; incarceration, n = 1). SVR was 91% (79 of 87, 95% CI, 83%-96%). Five participants who completed treatment did not have SVR (loss to follow-up, n = 1; death, n = 1; virologic relapse, n = 3). Drug use prior to and during treatment did not impact SVR12. Treatment-related adverse events were observed in 46 (53%) patients (six grade 3, no grade 4). Five (6%) patients had at least one serious adverse event (two possibly/probably related to therapy; nausea and myoclonus). Two cases of reinfection were observed. Conclusion: Paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without ribavirin for 12 weeks is effective among people with HCV genotype 1 with recent injecting drug use and/or receiving OST.