Impact of early viral kinetics on pegylated interferon alpha 2b plus ribavirin therapy in Japanese patients with genotype 2 chronic hepatitis C

Summary. The recommended therapy for genotype‐2 chronic hepatitis C is a regimen of pegylated interferon alpha (peginterferon) plus ribavirin. This study was conducted to determine the value of early viral kinetics as a predictive factor for sustained virologic responder (SVR). Peginterferon alpha 2b (1.5 μg/kg/week) plus weight‐based ribavirin (600–1000 mg/day) was administered to 51 patients with chronic HCV genotype 2 for 24 weeks. The HCV‐RNA loads were measured at the baseline, hour 24, and week 1. The rebound index (RI, an index obtained from the viral load of week 1 divided by that of hour 24) was calculated. Compared with the baseline, the viral load at hour 24 for SVR was reduced by more than 1‐log: it continued to decline thereafter, and at week 1 it was significantly lower than at hour 24 (P < 0.05). The viral load for non‐SVR increased again between hour 24 and week 1. The SVR of patients with RI ≤1.0 was 100% (39/39). The SVR conversion for rapid virologic responders was 92% (35/38). The RI (≤1.0) was the only significant independent factor for SVR by multiple logistic regression analysis and is the first predictive factor in 24‐week peginterferon plus ribavirin therapy for patients infected with genotype 2.