The impact of interferon plus ribavirin on response to therapy in black patients with chronic hepatitis C

Abstract

Black patients with chronic hepatitis C have lower response rates than white patients to interferon monotherapy. The factors responsible for these differences are unknown, as is the impact of combination antiviral therapy on responsiveness among ethnic groups. We evaluated the impact of race on response to therapy in these patients. A total of 1744 patients with chronic hepatitis C were randomized in 2 recent clinical trials to receive 24 or 48 weeks of interferon monotherapy or interferon-ribavirin combination therapy. Sustained virologic responses occurred in 27% of 1600 whites, 11% of 53 blacks (P = 0.01 vs. white), 44% of 32 Asians, and 16% of 27 Hispanics. No black patient had a sustained virologic response to interferon monotherapy, but 20% and 23% had sustained responses to 24 and 48 weeks, respectively, of combination therapy. Among black patients, 96% had hepatitis C genotype 1 compared with 65% of white subjects (P < 0.0001). Sustained response rates were similar for black and white patients with genotype 1 infection (23% vs. 22%, respectively). Compared with whites, black patients were older, weighed more, and had higher median Histologic Activity Index scores but did not differ in sex, baseline alanine aminotransferase or hepatitis C virus (HCV)-RNA levels, degree of fibrosis or percentage with cirrhosis, or other demographic variables. White subjects had a significantly greater reduction in HCV-RNA levels than blacks at weeks 4, 12, 24, and 48 of therapy, but only for black patients treated with interferon monotherapy. The decreased reduction of HCV-RNA reduction among blacks was eliminated by combination therapy. These observations suggest that the impaired responsiveness of black patients to interferon monotherapy can be overcome partially by combination interferon-ribavirin therapy.