It was only through serendipity that I was able to attend the last day of the conference on Genomics, Race, and Health Disparities that I mentioned in my previous posting. My wife heard mention of the conference on a local NPR station while driving home from work. “This sounds like the kind of stuff you’re interested in,” she said. She was right!

The first day’s topics centered on genomics and race, and included a presentation by Dr. Rick Kittles of Ohio State University. Dr. Kittles was the founder of African Ancestry Inc. and currently Associate Professor in the Department of Molecular Virology, Immunology & Medical Genetics at Ohio State University. Dr. Kittles’ current work concentrates on “how DNA sequence variation contributes to susceptibility to common complex diseases…,” specifically prostate cancer, which in the USA has the highest incidence and prevalence rates among African Americans.

In the abstract of his presentation, Dr. Kittles writes “the observed population differences in prostate cancer incidence and mortality can not be explained completely by differences in access to and quality of health care, diet, or other lifestyle characteristics. Whether differences in the distribution of known or undefined genetic risk factors among different populations explain the disparity is unknown. What is known is that many prostate cancer candidate genes exhibit large differences in allele frequencies across different populations. The significance of these patterns has yet to be fully understood.”

The day also included presentations by Drs. Jay Cohn and Keith Ferdinand who were members of group who conducted the A-HeFT study [African-American Heart Failure Trial]. This study resulted in the 2005 FDA approval of the medication BiDil—a combination of hydralyzine and isosorbide—for treatment of congestive heart failure in “self-identified black patients.” BiDil was the first ever “race-specific” medication to gain FDA approval.

The second day was devoted to ethical, legal, and economic issues. BiDil was the focus of many of the second day presentations.

The history of BiDil is interesting. In 1997 the FDA declined to approve the combination medication for treatment of congestive heart failure because a large study [V-HeFT, the Vasodilator Heart Failure Trial] failed to show any advantage of BiDil in treating CHF. However, a re-analysis of the data showed that one group—self-identified African Americans with severe CHF—appeared to be helped by the medication. This prompted Nitromed Inc., the manufacturer of BiDil, to finance a second study—A-HeFT, the African American Heart Failure Trial–confined to a population of self-identified African Americans. The study concluded that BiDil did slow the progression of CHF in self-identified African Americans.

There’s no shortage of criticism of this study. I don’t want to get into all of these controversies more than to say that the components of BiDil are available as individual, generic medications at a much cost to patients.

Conference participant Dr. Keith Ferdinand, one of the A-HeFT researchers wrote:

Racial disparities and response to medications may be related to multifactorial conditions, including socioeconomic status, differences in access to screening and early treatment, and differences in how healthcare is delivered, especially to indigent minority populations. Biologic differences, however, within populations and across cannot be totally discounted. The inclusion of race as a characteristic must in the future take into account these other unmeasured variables.

In the future, genetic testing may better detail what it is in the self-identified status of race that characterizes increased risk of certain cardiovascular conditions and differences in drug response.

Another participant, University of California sociology professor Dr. Troy Duster wrote in the abstract of his presentation:

In the last five years, there has been considerable increase in the number of published articles documenting the health disparities between the majority white population and various other racially designated groups in the United States. This development was a direct result of the Congressional mandate given to the National Institutes of Health in 2000,to conduct research and report findings on the topic. It was inevitable that reports of patterned disparities between racially designated groups would resuscitate an old debate about whether there are important biological differences between such groups. There is now a new role in this debate for biotechnology firms committed to finding markets for pharmaceutical products that have failed to get past clinical trials aimed at the general population [a reference to Nitromed Inc.] By re-focusing a marketing strategy on racially designated populations, the industry has gathered support for medicines previously “racially neutral”. And this strategy has in turn forged strange bedfellow support from clinicians who claim selective advantage for their patients from such “racialized medicine”.

It’s my hope that there will be more gatherings of scholars to discuss these very important problems. It’s also my hope that any future conference organizers try to publicize their conference more widely.

Finally, here’s something I wrote several months ago that is, I think, apropos:

Although different ethnic groups may differ in their frequencies of genes affecting drug metabolism, to adopt a prescribing practice that treated every member of that group exactly the same would be a mistake. What is true for the group is not always true for the individual. A one-size-fits-all prescribing practice for members of a defined ethnic group runs the risk of prescribing the wrong drug to an individual with a poor result.

A much better prescribing practice—and one that will likely become a standard of care in the not-too-distant future—is to directly determine an individual’s genotype. If a physician is aware of genetically determined responses to a particular drug, and if there is a test for a marker of the genes involved, he or she can simply order the test and use the result to guide the optimum prescription. There are actually more of these tests currently available than most physicians suspect and many more in the development pipeline.

Technorati Tags: genomics, health disparities, race

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