Background: Chronic hepatitis C virus (HCV) infection is a major cause of morbidity and mortality among HIV-infected patients. Sofosbuvir is a first-in-class HCV NS5B inhibitor with potent pan-genotypic antiviral activity. We report a 2-part study that assessed the efficacy and safety of sofosbuvir in HCV/HIV-coinfected patients. Part A examined potential drug interactions between sofosbuvir and antiretrovirals (efavirenz, emtricitabine, tenofovir, zidovudine, lamivudine, atazanavir, ritonavir, darunavir, and raltegravir). Part B was a pilot study of sofosbuvir plus peginterferon-ribavirin administered for 12 weeks.
Methods: We enrolled noncirrhotic patients with chronic HCV infection (genotype, 1-6) and stable HIV. Part A followed a 5-cohort, open-label, multiple-dose, single-sequence design; part B followed an open-label, single-arm design. The primary end point of part B was sustained virologic response (defined as undetectable HCV RNA) 12 weeks after end of treatment (SVR12). This study is registered with ClinicalTrials.gov, number NCT01565889.
Findings: Thirty-eight patients were enrolled in part A and 23 in part B. In part A, no clinically significant drug interactions were observed between sofosbuvir and any of the antiretrovirals evaluated. In part B, 21 (91.3%) patients achieved SVR12. Two patients relapsed but none experienced on-treatment HCV virologic failure. Two patients discontinued study treatment because of adverse events (altered mood and anemia). No serious adverse events, HIV viral breakthrough, or decreases in CD4 percentage were reported in either part A or part B.
Interpretation: Sofosbuvir may be coadministered safely with many commonly used antiretrovirals. The addition of sofosbuvir to peginterferon-ribavirin was highly effective as assessed by SVR in HCV/HIV-coinfected patients.