No abstract

Background Direct acting anti-HCV drugs have demonstrated a high cure rate and favorable tolerability. The development of shorter courses of therapy may improve affordability and adherence. Sofosbuvir and ledipasvir together with ribavirin have yielded high efficacy when administered for 8, but not for 6 weeks. We hypothesized that addition of a third potent directly acting antiviral to sofosbuvir and ledipasvir would allow for shortened durations of therapy. Methods In this single center, open-label cohort, phase 2 atrial, sixty HCV GT-1 treatment naïve patients were sequentially enrolled onto three arms and treated with 12 weeks of sofosbuvir and ledipasvir (an NS5B nucleotide polymerase inhibitor and an NS5A inhibitor, respectively) (n=20); or 6 weeks with sofosbuvir, ledipasvir, and GS-9669 (a non-nucleoside NS5B inhibitor) (n=20) or 6 weeks with sofosbuvir, ledipasvir and GS-9451 (an NS3/4A protease inhibitor) (n=20). Patients and investigators were unmasked to treatment assignment. The primary efficacy analysis was SVR12 (HCV RNA less than the level of quantitation 12 weeks after treatment completion). Findings All subjects treated with sofosbuvir and ledipasvir for 12 weeks achieved SVR12 (95%CI: 83–100%). Nineteen of 20 patients (95% CI: 75–100%) treated with sofosbuvir, ledipasvir and GS-9669 achieved SVR12, with 1 patient relapsing 2 weeks after completion of therapy. Nineteen of 20 patients (95% CI: 75–100%) treated with sofosbuvir, ledipasvir, and GS-9451 for 6 weeks achieved SVR12, one patient was lost to follow up after achieving SVR4. There were no discontinuations of treatment due to adverse events. Interpretation In this small proof of concept study, two different three drug regimens administered for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Funding NIAID, National Cancer Institute and Clinical Center Intramural Program. Clinical Trials.gov number NCT01805882. The study was also supported in part by the German Research Foundation (DFG) by the clinical research unit KFO 129 and a Collaborative Research and Development Agreement between NIH and Gilead Sciences.