Purpose / DescriptionThis study is one of the first to examine the efficacy of a response-guided approach to treatment duration, comparing a standard 24-week duration of pegIFN-2b at a dose of 1 mcg/kg weekly plus weight-based ribavirin 1000-1200 mg daily with a “variable-duration” arm that treated at the same doses but allowed patients who achieved HCV viral suppression at week 4 to stop therapy after 12 weeks in treatment-naïve patients with genotype 2 and 3 HCV infection; those patients who failed to suppress completed 24 weeks of therapy. This variable-duration approach appeared to be as effective as the standard duration, achieving sustained virologic response in 77% patients compared to 76% in the standard-duration arm, with lower rates of adverse events and treatment withdrawal.