Dr Eric Lawitz and colleagues conducted 2 phase 3 studies in previously untreated patients with HCV infection.
In a single-group, open-label study, the researchers 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 2 studies, the primary end point was a sustained virologic response at 12 weeks after the end of therapy.
|The sustained virologic response in the single-group study was 90%|
|New England Journal of Medicine|
In the single-group study, the team reported a sustained virologic response in 90% of patients.
In the noninferiority trial, a sustained response was reported in 67% of patients in both the sofosbuvir–ribavirin group and the peginterferon–ribavirin group.
The research team found that response rates in the sofosbuvir–ribavirin group were lower among patients with genotype 3 infection than among those with genotype 2 infection.
Adverse events (including fatigue, headache, nausea, and neutropenia) were less common with sofosbuvir than with peginterferon.
Dr Lawitz's team concludes, "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."
"Adverse events were less frequent with sofosbuvir than with peginterferon."