Black people are increasingly underrepresented in U.S. trials for cancer treatments, a disparity that could lead to the approval of unsafe or ineffective drugs, according to new research published Monday. 

The potentially dangerous race gap is associated with an increasing number of clinical trials taking place overseas in Europe and Asia, which have significantly smaller Black populations than the United States. 

Among 21 clinical trials supporting 18 Food and Drug Administration drug approvals with both race and location data available, 64% included patients outside the country. Trials conducted primarily overseas enrolled less than half as many Black patients as trials conducted within the U.S., researchers from the Icahn School of Medicine at Mount Sinai Hospital in New York City said in a paper for the medical journal Cancer.

“The purpose of a clinical trial should be to look at the safety and efficacy of a drug for the population it’s intended to treat,” said lead author Serena Tharakan, a third-year medical student at Mount Sinai, in an interview with The Academic Times. “That means all patients — it shouldn’t just mean a subset of patients.”

Tharakan pointed to chemotherapy drug Doxorubicin, which researchers have found is more likely to cause heart damage in Black patients than patients of other races, as an example of why diversity in cancer trials is essential.  

“We know that there are certain drugs that might have worse side effects in certain populations,” she said. “And if we don’t know that during trials, then we don’t find out until these drugs go to market.” 

Tharakan wrote the paper alongside Mount Sinai professors Xiaobo Zhong and Matthew D. Galsky using data from trials that led to FDA drug approvals between 2015 and 2018. 

The FDA doesn’t require all clinical trials to report race or location data, meaning that studies can’t necessarily give a full picture of the problem. 

But among 49 global cancer drug clinical trials that did include race data, the Mount Sinai researchers found that Black patients accounted for just 2.5% of enrollment — even though Black and African American people made up 13.4% of the U.S. population in 2019, according to the Census Bureau. Those 49 clinical trials led to 35 FDA approvals.

The problem of insufficient representation in medical trials goes beyond cancer drugs. In a JAMA Network Open paper published in February, a group of researchers from medical schools including Harvard Medical School and Emory University found that Black people, Hispanics and men were consistently underrepresented in U.S. vaccine trials. 

Under the current system of trials and approvals, researchers and companies seeking U.S. approvals have plenty of motivation to move trials to potentially less representative countries overseas, according to the Mount Sinai researchers. 

Specifically, conducting trials in other countries can be cheaper and involve fewer regulatory hurdles. Conducting trials across multiple countries can also help researchers find more patients quickly. 

“I think it ultimately comes down to cost and time and efficiency,” said Tharakan. 

Both Tharakan and Laura Flores, the lead author of the study on vaccine trials and race, told The Academic Times that the FDA should require clinical trials to disclose the racial and ethnic makeup of participants. The FDA currently recommends such disclosure, but does not require it.

“If there are no teeth behind these guidelines, often they are forgotten,” Flores said last month. 

Tharakan added that, in addition to requiring racial data, the FDA should also make sure all studies include data on where studies took place. Location data was “even more difficult to obtain” than race data during her study, she said. 

In future studies, Tharakan said she would like to examine which foreign countries in particular are getting the most clinical trials that lead to FDA approvals, and how each country affects the overall racial composition of drug trials. The Cancer paper lumped all foreign countries together as non-American. 

“We looked at just the United States versus non-United States,” she said. 

Tharakan also pointed to the FDA’s narrow racial categorizations as a limitation on research. 

The FDA typically groups patients into five groups: White, Black or African American, Asian, Native American or Alaskan Native, or Other. This system of organization fails to capture the diversity of patients who are, for example, biracial. 

“There’s not a lot of nuance there,” she said. 

The study, “The impact of globalization of cancer clinical trials on enrollment of Black patients” or “Enrollment disparities and globalization of cancer trials,” published on Mar. 8 in Cancer, was authored by Serena Tharakan, Xiaobo Zhong and Matthew D. Galsky, Icahn School of Medicine at Mount Sinai.