Unlikely mix -- Race, biology and drugs

by Troy Duster
Monday, March 17, 2003
reprinted from the San Francisco Chronicle

When the biotech company VaxGen released the results of its long- promised AIDS vaccine trials last month, the only conclusion that could be drawn from the large-scale study was that the vaccine had no significant effect. Of the more than 5,300 volunteers, 5.7 percent of those who received the vaccine became infected with HIV, but an eerily similar 5.8 per cent of those who received a placebo also became infected.

Attempting to rescue a silver lining from this dark cloud, the company tried to latch onto a "finding" even thinner than the lining. Of the 314 African Americans in the sample, a total of 13 had HIV infections, including four women who received placebos. News media around the country picked up the spontaneously revised VaxGen message and broadcast loudly that blacks had a "78 percent protection" from this vaccine. Even more problematic, four Asian Americans were infected, a few more were not -- and there was a suggestion that the vaccine might work on people of color.

As any statistician will testify, the number of African Americans and Asians is so small that one can have no confidence in these "findings." But that is precisely where the story starts to get interesting. To understand why, it is necessary to place the VaxGen story in the wider context of a controversy that is stirring deep and strong divisions in the fields of pharmacogenomics, epidemiology and pharmacotoxicology -- the appropriate role, if any, of race, in the effective delivery of drugs and vaccines.

This controversy will surely hit the headlines before the end of year, because in late fall we will learn the fate of a drug designed to be marketed specifically for blacks with heart disease. In what has been touted as "the first ethnic drug," the biotech firm NitroMed received a green light from the Food and Drug Administration in March 2001 to proceed with a full-scale clinical trial, "the first prospective trial conducted exclusively in black men and women suffering from heart failure." The drug is BiDil, and the study has been endorsed by the Association of Black Cardiologists.

The BiDil story has some fascinating parallels with the VaxGen story. BiDil is a drug designed to restore low or depleted nitric oxide levels to the blood to treat or prevent cases of congestive heart failure. It was originally designed for a wide population base, and race was irrelevant. But the early clinical studies revealed no compelling results, and an FDA advisory panel voted 9 to 3 against approval.

In a remarkable turn of fate, however, BiDil was suddenly born again as a racialized intervention. This new BiDil trial reflects two problematic assumptions about race and medicine:

The first is that African Americans' risk of developing and dying from heart failure is twice that of whites. This claim has been floating around in the scientific literature for a decade, mainly uncontested. Jonathan Kahn of the University of Minnesota, has just completed some remarkable scientific sleuthing on the topic, however, and has shown that the NitroMed claim about the scope of black and white differences is simply untrue. Kahn traced the citation sources back nearly two decades, and has demonstrated conclusively that the difference between blacks and whites is actually closer to 1.2 to 1. There is a difference, but it is nowhere near the 2-to-1 ratio that would warrant special trials for one population group. Thus, substantial scaffolding of the BiDil clinical trial is based upon incorrect statistical data on racial disparities.

The second claim is that BiDil has a special effect greater on African Americans than whites. The clinical trials now under way are not designed to test that hypothesis. Rather, by concentrating only on blacks, the study can have little or nothing compelling to say about comparative results, by race.

Why the mistake, and what is at stake? Part of the answer lies in the role of prospective markets for biotech products. While the new mantra of biotechnology is to claim that pharmaceuticals will someday soon be marketed to individuals based upon their DNA, the fundamental truth is that selling drugs is about markets. These markets are not about individual designer drugs, but about groups and population aggregates that become the target market.
In a classical piece of epidemiological research, Michael Klag and his associates showed a decade ago that, in general, the darker the skin color, the higher the rate of hypertension for American blacks, even inside the African American community. Klag indicated that the issue was not biological or genetic in origin, but biological in effect due to stress-related outcomes of reduced access to valued social goods such as employment, promotion, housing stock, etc. The effect was biological, not the origins.

It is difficult to bring anti-discrimination to the market, and as time goes by, it is harder and harder to bring it to the government's attention. But racialized drugs? They may soon be on the drugstore shelves.

Troy Duster is Chancellor's Professor of Sociology at the University of California at Berkeley. He also teaches sociology at New York University.