10 November 2004

Drugs Targeted by Race

Results of a recent drug trial have sparked discussion of the pros and cons of targeting therapies by race. Americans of African descent have worse problems with heart disease than the U.S. population as a whole. Many causes have been blamed, including lack of access to the health system, quality of care, environmental factors and lifestyle as well as possible genetic factors.

Since black Americans suffer disproportionately from heart disease, the Nitromed company decided to run a trial of its new drug BiDil® (a combination of the older generic drugs isosorbide dinitrate and hydralazine) including only blacks with severe heart disease. The results are due out in the next New England Journal of Medicine and are available in early release at their website.

The new combination pill, when added to standard therapy, had significant benefit, reducing the chance of hospitalization for and death from heart failure, and improving quality of life. Nitromed hopes to have the pill approved for this specific indication -- severe heart disease in blacks -- by next year.

Here are some of the headlines generated by the announcement of this research.
The modern consensus is that "race" is at best only a very crude way of categorizing people. (Only about 5% of genetic variability in humans is between ethnic/racial groups. You differ just as much genetically from others of your "race" as you do from those of other races. However, there are obviously specific genetic differences between races -- in fact we use markers like skin pigmentation, eyelid folds, and hair characteristics to create racial categories.)

Some experts suggest that this therapy might work just as well in heart-disease patients of other races. (However, a large trial years ago with veterans of all races found no significant benefit from these specific drugs. Researchers were later able to discern some benefit among black subjects, which led to the current trial.) Experience with other heart-failure drugs indicates lower effectiveness in African Americans than in European Americans, so any way to help this population is welcome.

An editorial accompanying the publication of these results in the New England Journal of Medicine asks, "are we moving into a new era of race-based therapeutics?" This is an awkward question, given that race is such a crude category, but at the same time, says the editorial, the medical establishment shouldn't shy away from the potential benefits of race-conscious therapeutics.

There is widespread interest in tailoring therapies to patients' specific genetic backgrounds. Perhaps categorizing patients by race can be useful until we develop more specific markers for heart-failure risk and drug response.

(The Association of Black Cardiologists was cosponsor of the Nitromed trial.)

What do you think?

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