Chronic hepatitis C virus genotype 6 infection: Response to pegylated interferon and ribavirin

Background. To date, no study has evaluated pegylated interferon for the treatment of chronic infection with hepatitis C virus (HCV) genotype 6. We aimed to determine the efficacy of pegylated interferon plus ribavirin for treating infection with genotype 6 versus genotype 1. Methods. Forty- two patients chronically infected with HCV (for genotype 1, n = 21; for genotype 6, n = 21) were treated with pegylated interferon alpha-2a (n = 20) or alpha-2b (n = 22) combined with oral ribavirin for 48 weeks. Results. There was no difference between genotypes 1 and 6 in the rates of early virological response (76% vs. 81%; P >.05) and end-of-treatment response (71% vs. 81%; P >.05). Patients infected with genotype 6 had a higher rate of sustained virological response (SVR) than did patients infected with genotype 1 (86% vs. 52%; P = .019). The overall adverse- effects profile was similar in both genotype groups. There was no significant difference in the rate of SVR between patients receiving pegylated interferon alpha- 2a and those receiving alpha- 2b. Multivariate analysis showed that genotype was the only significant factor associated with SVR (P = .039). Conclusions. Treatment with pegylated interferon and ribavirin for 48 weeks resulted in a significantly higher rate of SVR in patients infected with genotype 6 than in those infected with genotype 1. Further studies are required to determine whether lower dosages and 24 weeks of therapy may be sufficient for the treatment of genotype 6 infection.