Impact of Clinical Trial Design on Recruitment of Racial and Ethnic Minorities

Knowledge related to how oncology treatment trial design influences enrollment of racial and ethnic minorities is limited. Rigorous identification of clinical trial design parameters that associate favorably with minority accrual provides educational opportunities for individuals interested in designing more representative treatment trials. We identified oncology trials with a minimum of 10 patients at an NCI-Designated Comprehensive Cancer Center from 2010 to 2021. We defined a study endpoint of racial and ethnic minority accrual greater than zero. Multivariable logistic regression was used to determine whether co-variables predicted our study endpoint. P-values of less than 0.05 were considered significant. A total of 352 cancer trials met eligibility criteria. These studies enrolled a total of 7981 patients with a total of 926 racial and ethnic minorities leading to a median enrollment of 10%. Trials open in community sites (yes versus no) were more likely to have a minority patient (OR, 2.21; 95% CI, 1.02-4.96) as well as pilot/phase I studies compared to phase II/III (OR, 3.19; 95% CI, 1.34-8.26). Trials incorporating immunotherapy (yes versus no) were less likely to have a minority patient (OR, 0.47; 95% CI, 0.23-0.94). Trials open in community sites as well as early phase treatment studies were more likely to accrue minority patients. However, studies including immunotherapy were less likely to accrue racial and ethnic minorities. Knowledge gained from our analysis may help individuals design oncology treatment trials that are representative of more diverse populations.