Investigators of a database study of pivotal clinical cancer trials that resulted in approval by the US Food and Drug Administration (FDA) of oncology therapeutic agents revealed that more than one-third of the trials did not report participant race. Additionally, one-quarter reported subgroup analyses by race and identified disparities in the representation of black and Hispanic participants compared with their proportion of cancer burden, according to a review published in JAMA Oncology.
The researchers evaluated the frequency of race reporting and race representation in pivotal drug trials that are used to establish standards of care in oncology treatment.
Using FDA archives, the investigators systematically identified all FDA oncology drug approvals granted between July 2008 and June 2018. All primary reports from corresponding trials that resulted in the FDA-approved therapeutic agents were obtained using PubMed and ClinicalTrials.gov databases. US population-based cancer rates by race were derived from the National Cancer Institute Surveillance, Epidemiology, and End Results Program database and mortality data from the US census. The primary study end points were the proportion of oncology drug trials reporting race and the proportion of patients of a specific race who participated in these trials. Secondary end points were the proportion of trials reporting race subgroup analyses, and the discrepancy between race representation in trials and cancer burden by race in the United States.
The investigators identified 230 trials supporting FDA oncology drug approvals, of which 145 (63%) reported on at least 1 race as a baseline characteristic, 18 (7.8%) reported on all 4 major US races (white, Asian, black, Hispanic), and 58 (25.2%) reported at least 1 subgroup analysis by race. In total, 144 (62.6%) trials reported on the white race, 110 (47.8%) reported on the Asian race, 88 (38.2%) reported on the black race, and 23 (10%) reported on the Hispanic race. Trials reporting on race and subgroup analysis by race varied between the first 5 years and last 5 years of the study period: 45 trials (56.6%) reported on race in 2008 to 2013 vs 100 trials (67.1%) in 2013 to 2018 (odds ratio [OR], 1.63; 95% CI, 0.93-2.87; P =.09); 13 trials (16.1%) reported race subgroup analyses in 2008 to 2013 vs 45 trials (30.2%) in 2013 to 2018 (OR 2.26; 95% CI, 1.16-4.67; P =.03).
The overall representation of whites, Asians, blacks, and Hispanics among trial participants was 76.3%, 18.3%, 3.1%, and 6.1%, respectively. Compared with the proportion of cancer incidence reported in the United States, blacks and Hispanics were consistently underrepresented in oncology trials as compared with whites and Asians, who nearly matched their expected proportion.
A limitation to the study was extrapolation of analysis to US population from some studies with global recruitment; although adjustments were made using sensitivity analysis, there may have been some remaining skew for different racial/ethnic mixes. Further, estimates of cancer incidence did not account for genetic variability within diverse races. Trials that did not report on race may have had low rates of minority enrollment, which could result in an underestimation of the disparities.
Among trials that have led to FDA oncology drug approvals, the number of those with race reporting and subgroup analysis by race has historically been low. In trials that did report race, black and Hispanic races were notably underrepresented considering the incidence of cancer in these populations. The researchers concluded that greater proportional minority representation in clinical trials is critical to ensure the equitable representation of the entire US population.
Loree JM, Anand S, Dasari A, et al. Disparity of race reporting and representation in clinical trials leading to cancer drug approvals from 2008 to 2018 [published online August 15, 2019]. JAMA Oncol. doi: 10.1001/jamaoncol.2019.1870