Sofosbuvir for previously untreated chronic hepatitis C infection.

Area of Science:

• Hepatology and Viral Gastroenterology
• Pharmacological Sciences
• Clinical Trial Design and Analysis

Background:

• Phase 2 trials indicated sofosbuvir's effectiveness against chronic hepatitis C virus (HCV) genotypes 1, 2, and 3 in treatment-naive individuals.
• Sofosbuvir is a nucleotide polymerase inhibitor with demonstrated antiviral properties.

Purpose of the Study:

• To evaluate the efficacy and safety of sofosbuvir-based regimens in previously untreated patients with chronic HCV infection across different genotypes.
• To compare sofosbuvir plus peginterferon alfa-2a and ribavirin against peginterferon alfa-2a and ribavirin for HCV genotypes 2 and 3.

Main Methods:

• Two Phase 3 studies were conducted: a single-group, open-label study of a 12-week sofosbuvir, peginterferon alfa-2a, and ribavirin regimen for genotypes 1, 4, 5, or 6.
• A noninferiority trial randomized 499 patients with HCV genotypes 2 or 3 to either 12 weeks of sofosbuvir plus ribavirin or 24 weeks of peginterferon alfa-2a plus ribavirin.
• The primary endpoint in both studies was sustained virologic response (SVR) at 12 weeks post-therapy.

Main Results:

• The single-group study achieved a 90% SVR rate (95% CI: 87-93%) in patients with predominantly HCV genotypes 1 or 4.
• In the noninferiority trial, both sofosbuvir-ribavirin and peginterferon-ribavirin groups achieved a 67% SVR rate.
• Sofosbuvir-based regimens were associated with a lower incidence of adverse events compared to peginterferon.

Conclusions:

• Sofosbuvir in combination with peginterferon and ribavirin is highly effective for treating HCV genotypes 1 and 4, achieving 90% SVR.
• For HCV genotypes 2 and 3, sofosbuvir plus ribavirin demonstrated comparable efficacy to peginterferon plus ribavirin, with improved safety.
• Adverse events were less frequent in treatment arms containing sofosbuvir, highlighting its favorable safety profile.