The efficacy of extended treatment with pegylated interferon plus ribavirin in patients with HCV genotype 1 and slow virologic response in Japan.

Background: Which patients with hepatitis C virus (HCV) genotype 1 can benefit from extended treatment with pegylated interferon (Peg-IFN) plus ribavirin is unknown, although the overall sustained virologic response (SVR) rate has been shown to improve in patients with a late virologic response (LVR), defined as detectable serum HCV RNA at week 12 and undetectable at week 24.
Methods: Among 1163 chronic hepatitis C patients with genotype 1 treated with Peg-IFN plus ribavirin combination therapy, 213 patients with an LVR were examined in this study. In addition, we selected 81 patients of matched sex and age from each of the 48- and 72-week treatment groups, using the propensity score, to compare the efficacy of the two treatment durations.
Results: With 72-week treatment, the timing of HCV RNA disappearance and the hemoglobin level at baseline showed a strong correlation with the SVR on multivariate analysis. Earlier HCV RNA disappearance was associated with a better SVR rate, regardless of the ribavirin dose (HCV RNA disappearance at week 16, 74%; at week 20, 52%; and at week 24, 31%, p = 0.01). The SVR rate with 72-week treatment was higher than that with 48-week treatment, irrespective of age, sex, or the platelet value, and, especially in aged patients (≥65 years old), the SVR rate increased markedly with 72-week treatment (48 weeks, 25% vs. 72 weeks, 56%; p < 0.05).
Conclusions: An earlier response predicts a higher SVR rate in patients with an LVR given 72-week treatment. Extended treatment with Peg-IFN plus ribavirin for patients with an LVR improved the treatment efficacy, even for aged patients.