Lack of racial diversity in cancer drug trials

New research published in JAMA Oncology has found a lack of racial and ethnic diversity in clinical trials for cancer drugs.

The study—conducted by researchers from UBC, the University of Texas MD Anderson Cancer Center, the Fred Hutchinson Cancer Center in Seattle, and Baylor University in Texas—raises concerns about the effectiveness of cancer drugs in some patients, especially since genetic differences may affect how well a patient responds to a drug.

The researchers found that fewer than 8% of cancer drug trials reported participation from the four major races in the United States—white, Asian, black, and Hispanic—between 2008 and 2018. Black and Hispanic patients were particularly underrepresented at 22% and 44%, respectively, considering their populations’ incidence of cancer. The findings show that the science might not be applicable to the population that’s going to receive the medications. The researchers found that both reporting about race in trials and enrolment rates had changed minimally over the decade.

For this study, Dr Jonathan Loree (assistant professor, UBC Department of Medicine, Division of Medical Oncology) and colleagues reviewed all reported trials supporting US Food and Drug Administration oncology drug approvals granted between July 2008 and June 2018. They scrutinized 230 trials with a total of 112 293 participants. They calculated the US population-based cancer estimates by race using National Cancer Institute and US census data.

Although the researchers used US data, Dr Loree says the findings are relevant in Canada, as well. Pharmaceutical companies typically apply for drug approvals through the FDA first, because it serves the largest market, and then submit to the European Medicines Agency and Health Canada. The trials considered in the approvals are usually the same.

Dr Loree also notes that they weren’t able to analyze the participation of Indigenous people in trials because there were only 13 patients reported out of a total of 112 000 participants.

The researchers are now looking at whether clinical trials represent the same gender ratio as the general population to ensure the drugs are effective in all people.