Sofosbuvir plus ribavirin with or without peginterferon for the treatment of hepatitis C virus: Results from a phase 3b study in China.

BACKGROUND AND AIM: Sofosbuvir is a nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B RNA polymerase with pangenotypic potency. This phase 3b study evaluated the safety and efficacy of sofosbuvir + ribavirin ± peginterferon in Chinese patients infected with HCV genotype 1, 2, 3, or 6. METHODS: Patients with genotype 1 or 6 received sofosbuvir + peginterferon/ribavirin for 12 weeks or sofosbuvir + ribavirin for 24 weeks, depending on prior treatment and interferon eligibility. Patients with genotype 2 or 3 received sofosbuvir + ribavirin for 12 or 24 weeks, respectively. The primary endpoint was sustained virologic response at 12 weeks after the end of treatment (SVR12). RESULTS: Of 389 patients, 42% had genotype 1, 16% genotype 2, 32% genotype 3, and 9% genotype 6. Half were male, 58% were treatment-naïve, and 15% had cirrhosis. SVR12 rates for patients receiving 12 weeks of sofosbuvir + peginterferon/ribavirin were 94% (95% confidence interval [CI], 87-98%) for HCV genotype 1 and 97% (95% CI, 84-100%) for genotype 6. SVR12 rates for those receiving sofosbuvir + ribavirin for 24 weeks were 95% (95% CI, 87-99%) for genotype 1, 100% (95% CI, 40-100%) for genotype 6, and 95% (95% CI, 90-98%) for genotype 3. For genotype 2 patients receiving sofosbuvir + ribavirin for 12 weeks, the SVR12 rate was 92% (95% CI, 83-97%). Twenty patients (5%) relapsed. Ten (3%) experienced serious adverse events. Three (< 1%) discontinued treatment because of adverse events, of whom one died because of treatment-unrelated adverse events. CONCLUSIONS: Sofosbuvir-based regimens were highly effective and safe in Chinese patients with HCV genotype 1, 2, 3, or 6, suggesting sofosbuvir could serve as the backbone for HCV treatment in China irrespective of genotype.

Sofosbuvir for previously untreated chronic hepatitis C infection.

BACKGROUND: In phase 2 trials, the nucleotide polymerase inhibitor sofosbuvir was effective in previously untreated patients with chronic hepatitis C virus (HCV) genotype 1, 2, or 3 infection. METHODS: We conducted two phase 3 studies in previously untreated patients with HCV infection. In a single-group, open-label study, we administered a 12-week regimen of sofosbuvir plus peginterferon alfa-2a and ribavirin in 327 patients with HCV genotype 1, 4, 5, or 6 (of whom 98% had genotype 1 or 4). In a noninferiority trial, 499 patients with HCV genotype 2 or 3 infection were randomly assigned to receive sofosbuvir plus ribavirin for 12 weeks or peginterferon alfa-2a plus ribavirin for 24 weeks. In the two studies, the primary end point was a sustained virologic response at 12 weeks after the end of therapy. RESULTS: In the single-group study, a sustained virologic response was reported in 90% of patients (95% confidence interval, 87 to 93). In the noninferiority trial, a sustained response was reported in 67% of patients in both the sofosbuvir-ribavirin group and the peginterferon-ribavirin group. Response rates in the sofosbuvir-ribavirin group were lower among patients with genotype 3 infection than among those with genotype 2 infection (56% vs. 97%). Adverse events (including fatigue, headache, nausea, and neutropenia) were less common with sofosbuvir than with peginterferon. CONCLUSIONS: In a single-group study of sofosbuvir combined with peginterferon-ribavirin, patients with predominantly genotype 1 or 4 HCV infection had a rate of sustained virologic response of 90% at 12 weeks. In a noninferiority trial, patients with genotype 2 or 3 infection who received either sofosbuvir or peginterferon with ribavirin had nearly identical rates of response (67%). Adverse events were less frequent with sofosbuvir than with peginterferon. (Funded by Gilead Sciences; FISSION and NEUTRINO ClinicalTrials.gov numbers, NCT01497366 and NCT01641640, respectively.).

Sofosbuvir (GS-7977) plus peginterferon/ribavirin in treatment-naïve patients with HCV genotype 1: a randomized, 28-day, dose-ranging trial.

BACKGROUND & AIMS: Sofosbuvir (formerly GS-7977) is a pyrimidine nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B polymerase. We assessed the safety, tolerability, antiviral activity, and pharmacokinetics of sofosbuvir plus pegylated-interferon (PegIFN)/ribavirin (RBV) in a 28-day, dose-ranging trial in treatment-naïve patients infected with genotype 1 HCV. METHODS: In this double-blind study, 64 patients were randomized (1:1:1:1) to receive one of three once-daily doses of oral sofosbuvir (100, 200, or 400mg) or placebo plus PegIFN/RBV for 28 days, after which all patients continued to receive PegIFN/RBV alone for a further 44 weeks. RESULTS: Patients in the sofosbuvir/PegIFN/RBV groups experienced mean reductions in HCV RNA >5 log10 IU/ml (-5.3 for 100 mg, -5.1 for 200 mg and -5.3 for 400 mg) vs. -2.8 log10 IU/ml for placebo/PegIFN/RBV after 28 days. Rapid virologic response (RVR) rates were markedly higher after sofosbuvir treatment (88-94%) than placebo (21%), as were rates of sustained virologic response (SVR) at post-treatment Week 24 (56%, 83%, and 80% for sofosbuvir 100, 200, and 400 mg, respectively, vs. 43% for placebo). The number of patients experiencing virologic breakthrough and post-treatment relapse was higher in the sofosbuvir 100 mg group than sofosbuvir 200 and 400 mg groups. Sofosbuvir was well tolerated; the most frequent adverse events were fatigue and nausea. CONCLUSIONS: These results support further studies with sofosbuvir at 200 mg and 400 mg to determine the optimal dose and treatment duration of sofosbuvir in HCV genotype 1.