Sustained virological response based on the week 4 response in hepatitis C virus genotype 1 patients treated with peginterferons α-2a and α-2b, plus ribavirin

Abstract

It is unclear whether the magnitude of reduction in hepatitis C virus (HCV) RNA between baseline and week 4 of peginterferon-ribavirin treatment influences the probability of achieving a sustained virological response (SVR) in patients without a rapid virological response (RVR). Data of 151 genotype 1 chronic hepatitis C patients treated with 48 weeks of peginterferon α-2a (group 1, n=86) and peginterferon α-2b (group 2, n=65), plus ribavirin, were evaluated retrospectively. Patients of each group were further divided into those who had RVR and those who did not. Patients without an RVR were then subdivided into four discrete categories on the basis of the magnitude of decrease in HCV RNA from baseline to week 4: those with a ≥3 log10 drop, those with a ≥2 log10 but <3 log10 drop, those with a ≥1 log10 but <2 log10 drop, and those with a <1 log10 drop. The proportion of SVR was calculated for each category. Overall, 80 and 88.2% of RVR patients and 41.2 and 39.6% of non-RVR patients achieved an SVR in group 1 and group 2, respectively. Among non-RVR patients, the SVR rates were 75, 50, 16.7, and 11.1% in group 1 (trend test P=0.001) and 63.6, 42.9, 30, and 23.1% in group 2 (trend test P=0.038) in those with a drop in HCV RNA level of ≥3 log10, ≥2 log10, ≥1 log10, and <1 log10 at week 4, respectively. Patients with a ≥3 log10 drop in HCV RNA at week 4 have a high probability of achieving an SVR when treated with either peginterferon α-2a-ribavirin or peginterferon α-2b-ribavirin.