May 26, 2004 -- New research confirms that blacks are much less likely than whites to respond to hepatitis C treatment. But investigators say it is not because they have a higher incidence of infection with a hard-to-treat form of the virus.
In the Duke University study, roughly half of the non-Hispanic whites and just one out of five blacks were free of virus and considered cured six months after completing therapy. The findings are reported in the May 27 issue of The New England Journal of Medicine.
Earlier studies suggested that poorer cure rates among black patients may be due to the fact that they have a higher incidence of infection with the most difficult-to-treat strain of hepatitis C virus, genotype 1.
But an equal number of blacks and whites in the Duke study had the genotype 1 form of the virus.
"This study proves that genotype is not the reason for the poorer response to therapy among African Americans," lead investigator Andrew J. Muir, MD, tells WebMD. "It also highlights the need for research to help us understand why they do not respond as well and the importance of including a significant number of African Americans in future hepatitis C trials."
Response Rate Lower Than in Whites, But Better Than the Past
The rate of chronic hepatitis C infection is about twice as high for blacks in the United States as for non-Hispanic whites, and the rate of infection with the genotype 1 strain of the hepatitis C virus for blacks in the U.S. is close to 90%, compared to just under 70% for other ethnic groups.
Muir and colleagues assessed treatment outcomes among 100 black and 100 non-Hispanic white people with hepatitis C who were being treated at community clinics in four southern states. All patients were treated for 48 weeks with the combination therapy PEG-Intron and Rebetol (peginterferon alfa-2b and ribavarin).
Six months after completing treatment, 19% of the black patients had undetectable levels of virus in their blood; that's a sign indicative of a cure, compared with 52% of the white patients. Black patients also had significantly lower response rates after three months of treatment and immediately after treatment ended.
Muir tells WebMD that despite the difference in treatment outcomes, it would never be justifiable to withhold hepatitis C treatment on the basis of race alone. He points out that the 19% response rate to treatment seen among blacks is higher than that achieved in all patients treated with early hepatitis C drugs just over a decade ago.
"The decision to treat any hepatitis C patient is a complex one, and this is just one of the factors that needs to be weighed in discussions between physicians and African-American patients," he says.
Patients Still Benefit
Alexandria, Virginia physician Jonathan McCone, MD, who was a participating investigator in the Duke study, adds that many patients who do not achieve sustained responses to treatment still seem to benefit from it.
"I have seen this personally in my practice and studies have shown this," McCone tells WebMD. "Therapy actually reverses some of the liver damage and buys patients time by keeping them healthy so they don't degenerate to the point of needing a liver transplant or developing liver cancer."
McCone added that findings from this and other studies can be seen as encouraging because responses to early hepatitis C treatments among black patients was close to zero.
"Just a few years ago response to treatment was poor for everybody and absolutely horrible for African Americans," he says. "We now see sustained viral clearance in 20%-25% of a historically difficult to treat population. That is pretty significant."
SOURCES: Muir et al., The New England Journal of Medicine, May 27, 2004; Vol. 350: pp. 2265-2271. Andrew J. Muir, MD, assistant professor of medicine, division of gastrointerology, Duke University Medical Center, Durham, NC. Jonathan McCone, MD, director, Mount Vernon Endoscopy Center, Alexandria, VA. Bruce Bacon, MD, professor of internal medicine; division of gastrointerology and hepatology, St. Louis University School of Medicine.