Revisiting Race in Medicine
Via Medpundit, an article in Scientific American arguing against race-based medicine. I spoke about this on an aside in a post a few days ago, but now I feel like I have to respond to the Scientific American article. Note that I’m not defending BiDil here, but the concept of race-based medicine in general.
I don’t think the trend for race or ethnicity targeted drugs is a bad thing, overall, because first, we wouldn’t have a shortage of new drugs for everyone, since drug companies would only try for subpopulation-targeted drugs in a case where the drug has failed in a larger population. They want profits; they’re not going to limit the scope of any drug to a subpopulation — race-based or genetics-based or whatever — unless they had no choice; just look at how much they try to expand the indications of already approved drugs. And research produces so many drugs that fail clinical trials anyway that it might as well behoove industry to try drugs on sub-populations, since they’ve brought the drugs so far through the clinical process. So nothing to worry about on the economic side of things.
Secondly, taking race into account is better than not doing so, I think. It is simply wrong and counter-productive to claim that people can’t be grouped into ethnicity based on genetic polymorphisms. There are strong sub-population differences on polymorphisms of drug metabolizing enzymes, so what is toxic to one group may not be to the other. And saying that only 10 drugs or so have evidence to back up race-based indications doesn’t mean that we won’t see more in the future, now that more biological understanding is coming out about such things. But until personal genome sequencing and profiling becomes a lot less expensive and a lot faster than it is now, ethnicity, or even race, is a better substitute than nothing. After all, humans have, on a population scale, very homogeneous genetics, and the variation from continent to continent is pretty clear, with minor exceptions, so ethnicity is a valid and easily detectable, though crude, genetic marker. (Ironically, “black”, which is what BiDil was approved for, is probably the crudest and most meaningless sub-population indicator, since Africa has the most diverse genetic variation in the world.)
I do, however, hope that the FDA does not go lax with its requirements of efficacy. After all, race-targeted or not, the drug still has to work. I don’t believe that a head-to-head of one race versus another would be strictly necessary before approval of a drug, since that brings in ethical issues (testing a drug in populations where researchers expect the drug to fail). Anyway, if a drug really is effective in a larger population, post-approval clinical trials would be a lot easier to test, as they would already have gone through the three previous trials for efficacy and toxicity, and so it would be advantageous to allow the drug company to seek approval based on a limited subset first.
Basically, I see race-based or ethnicity-based medicine as part of the whole “personalized medicine” endeavor. Even though it’s crude, it’s still the first step, and it’s what we have to work with right now. We have drugs targeted based on age and sex already, and biologists very well know that age from birth is just a surrogate for “real” aging, and sex is just a surrogate for “real” hormonal levels, developmental history, and so on. Until we have better biological markers, age, sex, and even race and ethnicity, are good starting points for tailoring medicine to each person. We already do it, so why not with pharmaceuticals, too?
UPDATE: A nice New York Times article on natural selection on human subpopulations.
