June 1, 2004
Improved rates of response have resulted from recent advances in the treatment of hepatitis C virus (HCV), but several small studies have reported lower response rates among blacks than other racial or ethnic groups. Black patients are more likely to be infected with HCV genotype 1, which has a lower response rate than other genotypes. One study, however, reported no difference in response rates between black and white patients with HCV genotype 1. Low enrollment of blacks and retrospective designs limited previous studies. The authors of the present study prospectively compared response rates to treatment with peginterferon alfa-2b and ribavirin among blacks and non-Hispanic whites with chronic hepatitis C.
For 48 weeks, the researchers treated 200 chronic hepatitis C patients -- 100 blacks and 100 non-Hispanic whites -- with peginterferon alfa-2b and ribavirin. The primary end point for the study was a sustained virologic response, defined as a negative test for serum HCV RNA six months after completing therapy.
Ninety-eight percent of patients in both cohorts had genotype 1 infection. The rate of sustained virologic response was higher among non-Hispanic white patients (52 percent) than among black patients (19 percent). In addition, the black patients had significantly lower rates of virologic response at 12 weeks and at the end of treatment. In multivariable analyses examining sociodemographic and clinical characteristics, black race was the only variable significantly associated with the difference in response rate.
"The reason for the differences in response between black patients and non-Hispanic white patients with chronic hepatitis C remains unclear," the researchers reported. "Our findings demonstrate a limitation of current HCV therapy. Many novel therapies are under investigation, and our study highlights the importance of adequate enrollment of all racial and ethnic groups. Further research is also necessary to understand the poor response to therapy for chronic hepatitis C with interferon alfa among black patients, since such an understanding might lead to new therapies for all patients," the researchers concluded.