Is BiDil the start of race-based drugs?

Today, it was reported that a trial has shown that BiDil, a combination of hydralazine and isosorbide dinitrate, improved survival in blacks with congestive heart failure (CHF):

The final phase trials, involving more than 1,000 African Americans, were stopped early in July because of the “significant survival benefit”, according to the drug’s makers, NitroMed.

The treatment, which is a combination of two existing drugs, isosorbide dinitrate and hydralazine, was initially tested more than 20 years ago on white and black populations but was not thought effective enough to take forward.

This is important, because the medications normally used to treat CHF, such as ace-inhibitors and beta-blockers, are not as effective in blacks. Additionally, blacks have an increased risk of developing CHF.

There is controversy in developing race-based medications, or patients being prescribed the “black pill”:

That is “cause for celebration” for blacks, but the company now will have no financial incentive to do a larger trial in whites because its “black-only” patent allows it to sell it that way and keep generic versions from coming the market until 2020, he said.

Others worried that the drug might not be the best choice for every black but that they will automatically be prescribed “the black pill” solely on the basis of skin color.

Being black is not a black-and-white distinction, said Dr. Timothy Gardner of the University of Pennsylvania in Philadelphia, who had no role in the study. “Physiologically, it’s a sort of continuous variable,” including people of mixed races, he said.

Now, let’s look at BiDil a little closer. This is merely a combination of two cheap generic medications – hydralazine and isosorbide dinitrate. In fact, you can simply prescribe these medications separately at BiDil’s dosages for only pennies. This combination has been tested before in the pre ace-inhibitor era and was the standard of care for CHF before the emergence of ace-inhibitors. However, the data showed that blacks had a lesser response to ace-inhibitors, and that the older standard of hydralazine and nitrates had a more pronounced effects in blacks. The drug company, NitroMed, shrewdly pounced on this fact, leading to the results of today’s study.

It will be interesting to see the future effects of this dawn of race-based therapeutics. NitroMed now has this niche market locked up for its patent rights until 2020 – it has no incentive to conduct further costly studies to see if it applies to the general population. However, is this instance different from gender-based medications? Take Zelnorm for instance, a medication for irritable bowel syndrome in women. The only reason why it is only prescribed for females is that the study used to garner FDA approval only included women. Again, once Novartis locked up this niche market for its patent, it had no incentive to test the broader population. We are coming closer to the day where race and gender will influence how we treat disease – and introduces a host of new paradigms (one that comes to mind is how BiDil will affect the treatment of CHF in mixed races).

The study can be found at the NEJM, and includes their perspective.

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