Caution against FDA approval of race-based pharmaceutical

Feb 27 2005

New York University Sociologist Troy Duster concludes that a pharmaceutical to combat heart disease among blacks is based on faulty research and urges the Food and Drug Administration to obtain more reliable data before approving the drug.

Duster, president of the American Sociological Association, writes that research on isosorbide dinitrate and hydralazine (BiDil), produced by NitroMed, incorrectly links a biological idea of race to heart disease and that socioeconomic factors better explain susceptibility to heart disease. Duster's analysis appears in Science magazine.

"Race is such a dominant category in the cognitive field that it can leave its own indelible mark once given even the temporary imprimatur of scientific legitimacy by molecular genetics," Duster writes, expressing concern for the precedent the NitroMed study may set.

However, Duster encourages continued research to match genetics and medical treatment.

"An increased understanding of genetic diversity will help scientists doing gene-association studies by identifying new variants and reducing the likelihood of false-positive associations," he writes. "The hope is that it may aid scientists to identify medically relevant genes for diseases."

Initially, the FDA rejected its use to treat heart disease because of its ineffectiveness among the general population. However, the company began testing BiDil exclusively on blacks with FDA approvalafter theorizing that the drug's effect on nitric-oxide deficiency, which is more common in black heart-failure patients than in non-blacks, would be beneficial to a targeted racial population. NitroMed reported effectiveness of the BiDil in its clinical trial of 400 black women and 600 black men.

NitroMed, which intends to market the drug to African Americans after FDA approval, has noted that African Americans between the ages of 45 and 64 are two-and-a-half times more likely to die from heart failure than are Caucasians in the same age range. However, in the Science article, Duster responds that this age group accounts for only 6 percent of heart-failure mortality and that these statistical differences in heart failure between African Americans and Caucasians over 64 nearly disappear.

Duster bolsters his conclusions by drawing from previously published research on race and health risks. Findings published in the journal BMC Medicine, he writes, show that blacks from Africa, the Caribbean, and the United States show less disparity in hypertension rates than do whites from Europe, the United States, and Canada. The study also concluded that differences in hypertension rates between light-skinned African Americans and dark-skinned African Americans was attributed to the latter group having less access to medical and other resources in the United States.

"The ability to use genomic knowledge to deliver effective pharmaceuticals more safely to special subpopulations that have some functional genetic markers holds promise," Duster writes. "If the FDA approves BiDil, it should do so only under the condition that further research be conducted to find the markers that have the actual functional association with drug responsiveness, thus assuring that the drug be approved for everyone with those markers, regardless of their ancestry or of their ancestral informative markers."