To Screen or Not to Screen? - Pharmaceutical Executive


To Screen or Not to Screen?

Pharmaceutical Executive

"Population categories, including race and ethnic group, are clearly inadequate to describe fully the pattern and range of variation among individuals," wrote Charles Rotimi, PhD, director of the Center for Research on Genomics and Global Health, National Institutes of Health, and Lynn Jorde, professor and chair of human genetics at the University of Utah, in the New England Journal of Medicine last October. "A more accurate assessment of disease risk may be obtained by genotyping disease-associated genetic variants in individuals, rather than using population affiliation as a surrogate." The major problem with race is that it's self-identified: "Genetic analyses of individual ancestry show that some self-identified African-Americans have large proportions (more than 50 percent) of European genetic ancestry, whereas some self-identified European-Americans have substantial recent African genetic ancestry," wrote Rotimi and Jorde. Africa is the most genetically diverse continent on the planet; go back far enough, and we are all Africans.

But there are major barriers to genomic screening, namely cost and selection. There are also problems with sample diversity and storage for research. Issues like these won't stop pharmaceutical companies—and for now, perhaps they shouldn't—from conducting clinical trials based on racial designations, like the one AstraZeneca completed in mid-May, which studied the efficacy of Symbicort, an asthma drug, in 742 self-identified African-Americans. Results from AZ's 52-week study "are consistent with safety and efficacy data from the ... previous Symbicort studies conducted among predominantly Caucasian patients," according to a release on the study. (AstraZeneca declined to comment.) Self-reported African-American populations have shown a higher prevalence of asthma, compared with self-reported Caucasians. It's unclear what studies like these actually prove.

Toward the end of the first day at the Novartis symposium, Rotimi was on stage as part of a panel entitled, "A Transdisciplinary Approach to Addressing Health Disparities," when a member of the audience—Olufunmilayo Olopade, a professor of medicine and human genetics at the University of Chicago, and a recent Obama Administration appointee to the National Cancer Advisory Board—asked him a pointed question: "Charles, if you had the funding you'd like to have [to address health disparities], what would you do with it?" Rotimi responded, "If you handed me $2 million, and told me to go to Washington, DC, and make a difference, I wouldn't spend a dime on genomics."

The science of pharmacogenomics is progressing, and the cost of screening and full genotype mapping will come down, but before personalized medicine can deliver on its many promises, drug researchers will need to toss out racial designations that reduce the likelihood of diagnosis in other populations.


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