The objective of this analysis was to compare sustained virological response (SVR) and relapse rates in patients with a rapid virological response (RVR, HCV RNA <50 IU/mL at week 4) randomized to 24 or 16 weeks of treatment with peginterferon alfa-2a (40KD) 180 microg/week plus ribavirin 800 mg/day in the multinational ACCELERATE study. The analysis was restricted to patients who received treatment for 80% or more of the planned duration. Of 1309 eligible patients, 863 individuals (65.9%) achieved an RVR and were included in this analysis (458 assigned to 16 weeks and 405 assigned to 24 weeks). The overall SVR rate was significantly higher in patients randomized to 24 weeks of treatment (91% versus 82%; P = 0.0006) and among patients infected with genotype 2 (92% versus 81%; P = 0.0010) but not genotype 3 (90% versus 84%; P = 0.1308). Relapse rates were significantly lower among all patients randomized to 24 weeks of treatment: overall (6% versus 15%, P < 0.0001); in those infected with genotype 2 (5% versus 17%, P = 0.0001), and genotype 3 (7% versus 14%, P = 0.0489). SVR rates in patients with a viral load of 400,000 IU/mL or less randomized to 24 and 16 weeks of treatment were similar, 95% and 91% (P = 0.2012). Significant pretreatment predictors of SVR included assignment to 24 weeks of treatment (P = 0.0006), absence of advanced fibrosis on liver biopsy (P = 0.0032), lower HCV RNA level (P = 0.0017), and lower body weight (P < 0.0001).
Conclusion: The standard 24-week regimen of peginterferon alfa-2a (40KD) plus ribavirin is significantly more effective than an abbreviated 16-week regimen in genotype 2/3 patients who achieve an RVR. Abbreviated regimens may be considered in patients with a low baseline viral load who achieve an RVR.