Peginterferon and ribavirin treatment in African American and Caucasian American patients with hepatitis C genotype 1

Background&Aims: Compared with Caucasian Americans (CA), African Americans (AA) with chronic hepatitis C are less likely to respond to interferon-based antiviral therapy. Methods: In a multicenter treatment trial, 196 AA and 205 CA treatment-naive patients with hepatitis C virus (HCV) genotype 1 infection were treated with peginterferon alfa-2a (180 mu g/wk) and ribavirin (1000-1200 mg/day) for up to 48 weeks. The primary end point was sustained virologic response (SVR). Results: Baseline features were similar among AA and CA, including HCV-RNA levels and histologic severity, but AA had higher body weights, a higher prevalence of diabetes and hypertension, and lower alanine transaminase levels (P <.001 for all). The SVR rate was 28% in AA and 52% in CA (P <.0001). Racial differences in viral responses were evident as early as treatment week 4. Breakthrough viremia was more frequent among AA than CA (13% vs 6%, P =.05); relapse rates were comparable (32% vs 25%, P =.30). Proportions of patients with serious adverse events and dose modifications and discontinuations were similar among AA and CA. In multiple regression analyses, CA had a higher SVR rate than AA (relative risk, 1.96; 95% confidence interval, 1.48-2.60; P <.0001). Other factors independently associated with higher SVR included female sex, lower baseline HCV-RNA level, less hepatic fibrosis, and more peginterferon taken. Conclusions: AA with chronic hepatitis C genotype 1 have lower rates of virologic response to peginterferon and ribavirin than CA. These differences are not explained by disease characteristics, baseline viral levels, or amount of medication taken.