HEALTH :: DECEMBER 29, 2004

Last time we saw some of the good news about BiDil, a new combination of a couple of older drugs for treating congestive heart failure. Given to black patients in addition to other medications, BiDil increases life expectancy and improves quality of life. As blacks tend to suffer higher rates of heart failure, any medication targeted at this relatively greater-need group has to be seen as a plus.

Also, last time, I cited an excellent commentary in the New England Journal of Medicine by Dr. M. Gregg Bloche (http://content.nejm.org/cgi/content/abstract/NEJMp048271). Bloche fully appreciates the good news about BiDil but also warns us of some dangers.

The latest research on the human genome has shown that “race” has virtually no genetic basis. What this means is: Take a bunch of folks that call themselves white, and take another bunch that call themselves black. Check out the genetic differences within each group and between the two groups. You’ll find greater genetic variability within each “racial” group than between the two groups.

In other words, it is very chancy to try to use outward signs of “race” if what we really want to know about is the genes that put us at higher or lower risk for any particular disease.

The study that showed how well BiDil worked in black patients had a very pragmatic test for allowing people into the research trial: If you said you were black, then you were black. In other words, that study told us nothing about genes that explain why BiDil might work for some people and not for others.

The proponents of BiDil will tell us that this research is merely a stopping point along the road to real knowledge. “Blackness” is today just a handy, temporary marker. In a few years we’ll know more about the gene that makes BiDil effective for some people. We’ll then be able to do a genetic test to find out which people have it. Inevitably we’ll find that some blacks lack the key gene, and some whites have the gene. That will allow the medicine of the future to use the drug in a much more scientific, targeted way.

To this nice story, Bloche responds — where’s the money for the research? The drug company has a patent that allows it exclusive rights to sell BiDil to blacks for treatment of heart failure. It has, therefore, a considerable financial disincentive to go and find a genetic test that actually might lead to lower future sales.

Bloche throws in another wrinkle: Why are we so sure that the answer is in genes, anyway? One major cause of congestive heart failure is hypertension. We know blacks have more hypertension than whites. Is this because of “black genes”? Or might it have something to do with the social and psychological forces that afflict the black community proportionately more than the white community?

There is suggestive medical evidence that at least some of the heart disease burden in the black community is explained by stress and other social factors. But, again, where is the money to do the research? You can’t sell drugs by investigating the social forces that might contribute to disease. So long as we depend primarily on the drug industry to fund large-scale clinical research trials, some important scientific questions simply will not get answered.

We have seen, over the years, the downside of imagining that we can tell all about a person by looking at skin color and then imagining that “genes” explain and predict everything we need to know about that person. People who worry about all the implications of drugs specifically targeted at patients based on racial labels are not trying to take real cures away from needy patients. Instead they are trying to warn us of some real pitfalls, both in terms of science and in social policy. I think we’d do well to pay heed.