FDA may approve new heart drug for blacks

The medication would become the first to target cardiac disease in a minority population.

By Victoria Stagg Elliott, amednews staff. March 26, 2001.

The Food and Drug Administration is prepared to approve a drug for heart failure specifically in African-American patients if it proves effective in a clinical trial focused on this population.

BiDil, a combination of hydral-azine hydrochloride and isosorbide, has demonstrated some increased effectiveness in black vs. white congestive heart failure patients in retrospective studies.

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"African-Americans appear underserved with respect to currently available drugs for the treatment of heart failure," said Anne L. Taylor, MD, a professor of medicine at the University of Minnesota in Minneapolis. She will be organizing the study for the drug's manufacturer, NitroMed Inc. "The FDA's support of the continued development of a therapy for black heart failure patients represents a significant medical milestone. Once approved, BiDil will provide cardiologists with a critically needed pharmacologic treatment option."

Heart failure is twice as common and much more deadly in blacks than in whites, something experts ascribe to numerous factors, including reduced access to health care, increased rates of hypertension and differences in response to treatment.

Bridging the therapeutic gap

"We've known for some years that African-Americans fare less well with heart failure than do whites. There are many reasons for that," said Jay N. Cohn, MD, a professor of medicine at the University of Minnesota in Minneapolis and co-author of "Racial differences in response to therapy for heart failure: Analysis of the vasodilator-heart failure trials," published in the September 1999 Journal of Cardiac Failure. "We've now found that one of the reasons may well be that they don't respond as well to the drug. This will provide an opportunity to at least bridge the therapeutic gap," said Dr. Cohn.

Those involved in the project hope it will contribute to an increasing body of work that looks at differences in response to treatment or the path of disease among ethnic groups, just as it is now increasingly common to look at differences between the sexes.

"We're more alike than we are different," said Dr. Taylor. "But gender and ethnicity helps us understand the biology of health and disease."

Race has always been a contentious issue in the United States, and researchers' work is hampered by both a lack of minority study participants and a lack of minority researchers. "Unless you have someone looking at which differences are important and which are not, it's not going to get done," said Dr. Taylor.

Researchers concede, however, that skin color is only a rough means of determining genetic response to drugs -- useful only in the absence of yet-to-be-developed sophisticated genetic tests. Critics charge that race is far too imprecise a measure to predict a drug's possible effectiveness.

"It is without question that the African-American patient population, perhaps more so than any other ethnic group in this country, is a very heterogeneous group. It would be awkward to say that physiological responses to medicines would be similar or the same for all African-Americans," said Clyde Yancy, MD, associate professor of medicine and cardiology at the University of Texas Southwestern Medical School in Dallas. "It would also establish a dangerous precedent that there are some things you give to certain patients and, unfortunately, some things that you withhold. I cannot in good conscience accept a treatment approach that segregates a patient population from a therapy that is known to have good outcomes."

The initial study was also a retrospective review and not designed to look at racial differences in response to treatment. "That is a statistically challenging way to look at a study," said Dr. Yancy. "And it may not be the best way."

Researchers will start recruiting study subjects for the African-American Heart Failure Trial in May.

ADDITIONAL INFORMATION:

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Abstract, "Racial differences in response to therapy for heart failure," Journal of Cardiac Failure, September 1999 (vol. 5, issue 3) (http://www.harcourthealth.com/scripts/om.dll/serve?action=searchDB&searchDBfor=art&artType=abs&id=pm0010496190&nav=abs)

NitroMed Inc. (http://www.nitromed.com/)