Globalization of Cancer Clinical Trials Widens Racial Gap in Participation

By Reuters Staff

March 15, 2021

NEW YORK (Reuters Health) - The globalization of cancer clinical trials has led to fewer Black patients being enrolled, further exacerbating existing enrollment disparities in trials that ultimately lead to approval of new cancer drugs in the United States, researchers report.

A number of studies have investigated factors such as access to healthcare, physician biases and socioeconomic status that may lead to underrepresentation of Black patients in clinical trials.

However, the current study is the first to "quantitatively demonstrate that the globalization of cancer clinical trials may also be a key driver of racial disparities in the U.S. drug approval process," Serena Tharakan of the Icahn School of Medicine at Mount Sinai, in New York City, said in a statement.

Tharakan and colleagues reviewed 49 global clinical trials that supported 35 U.S. Food and Drug Administration (FDA) drug approvals in which data on race was available.

In these trials, Black individuals accounted for just 2.5% of enrollment (range, 0% to 10%), with a median disparity score of 0.19 (range, 0.01 to 0.98), a metric comparing Black enrollment in clinical trials with the estimated burden of disease in Black patients in the U.S. (a lower score means more disparity).

In the 21 clinical trials supporting 18 FDA drug approvals with both race and recruitment location data available, 64% of participants were enrolled outside the United States (range, 0%-100%) and Black individuals accounted for just 3% of enrollment (range, 0.2% to 10%); the median disparity score was 0.23 (range, 0.01 to 0.98).

The proportion of trial patients enrolled outside the United States correlated inversely with the disparity score (Pearson correlation, -0.61; P=0.007), the researchers report in Cancer.

"The past few decades have witnessed a dramatic shift in the clinical cancer research enterprise with the majority of study sites now located outside the United States," the researchers note in their article.

This analysis shows that the "globalization of cancer clinical trials may have the unintended consequence of further exacerbating existing racial disparities in cancer clinical trial representation and ultimately the generalizability of trial results."

"These findings may help inform regulatory science and policy focused on addressing racial disparities in cancer care," they conclude.

SOURCE: Cancer, online March 8, 2021.