Background & aims: This analysis reports the rate of sustained virological response (SVR) in patients infected with hepatitis C virus (HCV) genotype 1 or 4 who were assigned to 24 weeks of treatment with pegylated interferon (peginterferon) alfa-2a 180 mug/wk plus ribavirin 1000/1200 mg/day after achieving a rapid virological response (RVR; HCV RNA level <50 IU/mL) at week 4 in a prospective trial investigating response-guided therapy.
Methods: Non-RVR patients with an early virological response were randomized to 48 or 72 weeks of therapy (this is a still-ongoing trial).
Results: A total of 150 of 516 patients (29%) had an RVR, 143 of whom completed 24 weeks of treatment. Younger patients, leaner patients, and those with an HCV RNA level </=400,000 IU/mL and HCV genotype 4 infection were more likely to achieve an RVR; however, among patients with an RVR, no baseline factor predicted SVR. The SVR rate was 80.4% (115/143; 95% confidence interval [CI], 72.9-86.6) in patients who completed 24 weeks of treatment. The SVR rate was 86.7% (26/30; 95% CI, 69.3%-96.2%) in patients infected with genotype 4 and 78.8% in those infected with genotype 1 (89/113; 95% CI, 70.1%-85.9%; intent to treat: 89/120; 74.2%; 65.4-81.7%). Treatment was well tolerated.
Conclusions: This prospective study confirms that a 24-week regimen of peginterferon alfa-2a plus ribavirin 1000/1200 mg/day is appropriate in genotype 1 and 4 patients with a low baseline HCV RNA level who achieve an RVR by week 4 of therapy.