African-Americans with a difficult-to-treat strain of hepatitis C experience a “significantly lower response rate” than non-Hispanic whites to the drug combination peginterferon alfa-2b and ribavirin, according to research performed at Duke University Medical Center.
The study, led by Andrew Muir, an assistant professor of medicine at Duke University Medical Center, showed that 19 percent of blacks infected with the HCV genotype 1 strain responded to the drug combination compared with 52 percent of non-Hispanic whites with the same disease.
The researchers called the results in white patients “one of the highest response rates ever reported for this therapy,” and said they confirmed that the difference in infection rates between the two groups “is not responsible for the low response rate to treatment” in African-Americans.
The peginterferon alfa-2b/ribavirin combination therapy is marketed as Rebetron by Schering.
The study, which appears in the May 27 New England Journal of Medicine, “definitively proves that the difference in response rate is not due to the higher rate of genotype 1 infection in African-Americans,” Muir, who is also a gastroenterologist, said in a statement. He said that African-Americans should “consult their physicians about the decision to receive treatment” for HCV.
In their prospective study, Muir and colleagues followed 100 black and 100 non-Hispanic white patients with HCV during 48 weeks of drug treatment. Ninety-eight percent of both groups had the genotype 1 strain, which is the most common form of the HCV in the United States, and is “the most difficult to treat,” Muir said in his study.
Results from the research showed that African-Americans “have a higher rate of genotype 1 infection than non-Hispanic whites.” Muir explained that earlier studies suggested the prevalence of genotype 1 infection in African-Americans “was responsible for their lower response rate” to therapy. Yet by comparing similar patient groups, “the researchers determined that the difference in infection rates does not explain the lower response rate to treatment among African-Americans.”
Though statistical analyses many factors — patients’ sex, age, weight, education, duration of infection, and other medical conditions — “showed race was the only variable associated with a significant difference in response to treatment,” The reason behind the difference remains unclear.