BACKGROUND
The standard treatment for hepatitis C virus (HCV) infection is interferon, which is administered subcutaneously and can have troublesome side effects. We evaluated so fos bu vir, an oral nucleotide inhibitor of HCV polymerase, in interferon-sparing and interferon-free regimens for the treatment of HCV infection.
Methods
We provided open-label treatment to eight groups of patients. A total of 40 previously untreated patients with HCV genotype 2 or 3 infection were randomly assigned to four groups; all four groups received so fos bu vir (at a dose of 400 mg once daily) plus ribavirin for 12 weeks. Three of these groups also received peginterferon alfa-2a for 4, 8, or 12 weeks. Two additional groups of previously untreated patients with HCV genotype 2 or 3 infection received so fos bu vir monotherapy for 12 weeks or so fos bu vir plus peginterferon alfa-2a and ri ba vi rin for 8 weeks. Two groups of patients with HCV genotype 1 infection received so fos bu vir and ribavirin for 12 weeks: 10 patients with no response to prior treatment and 25 with no previous treatment. We report the rate of sustained virologic response 24 weeks after therapy.
Results
Of the 40 patients who underwent randomization, all 10 (100%) who received so fosbu vir plus ribavirin without interferon and all 30 (100%) who received so fos bu vir plus ribavirin for 12 weeks and interferon for 4, 8, or 12 weeks had a sustained virologic response at 24 weeks. For the other patients with HCV genotype 2 or 3 infection, all 10 (100%) who received so fos bu vir plus peginterferon alfa-2a and ribavirin for 8 weeks had a sustained virologic response at 24 weeks, as did 6 of 10 (60%) who received so fos bu vir monotherapy. Among patients with HCV genotype 1 infection, 21 of 25 previously untreated patients (84%) and 1 of 10 with no response to previous therapy (10%) had a sustained virologic response at 24 weeks. The most common adverse events were headache, fatigue, insomnia, nausea, rash, and anemia.
Conclusions
So fos bu vir plus ribavirin for 12 weeks may be effective in previously untreated patients with HCV genotype 1, 2, or 3 infection. (Funded by Pharmasset and Gilead Sciences; ClinicalTrials.gov number, NCT01260350.