Racial and ethnic enrollment disparities in clinical trials leading to FDA approvals for gynecologic malignancies.

Background: Black women and other minorities have higher age adjusted incidence risk for cervical and endometrial cancer than White women. However, the extent of racial and ethnic disparities in clinical trial enrollment among studies performed mainly in North America and Europe for gynecologic malignancy is unknown.

Objective: This study analyzed enrollment rates by race/ethnicity in trials that led to Food and Drug Administration (FDA) approvals for gynecological cancers from 2010 to 2024.

Study Design: This cross-sectional study examined clinical trials registered with ClinicalTrials.gov that resulted in new FDA approvals for gynecologic malignancies between 2010 and 2024. Exclusion criteria were studies not conducted in North America or Europe. Enrollment fractions were obtained by dividing the number of trial participants segregated by the racial/ethnic group by the corresponding U.S. cancer prevalence (uterine, ovarian, and cervical cancer) for 2016-2020 for each racial/ethnic group. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare enrollment fractions of minority groups to non-Hispanic (NH) Whites.

Results: A total of 31 studies met the inclusion criteria, with 21 reporting race/ethnicity data. Three (3/21) studies dichotomized race as NH-White and Non-White, and Seven (7/21) reported ethnicity. The median number of participants was 494 [interquartile range 150-674]. Fifteen studies were phase III, and six were phase IB/II trials. Treatments included immune checkpoint inhibitors (seven studies), PARP inhibitors (five), VEGF inhibitors (four), antibody-drug conjugates (four), and an imaging marker (one). Across all studies, 11,258 patients were included, 5,563 (49.4%) in ovarian cancer studies, 2,963 (26.3%) in endometrial cancer studies, and 2,732 (24.3%) in cervical cancer studies. Three studies (n=1,734) dichotomized participants into NH-White and Non-White (NH-White 1,291 [74.4%] and Non-White 443 [25.6%], and enrollment fractions were 0.51% for NH-White and 0.43% for No-White, with Non-White being underrepresented odds ratio (OR) 0.85. 95% confidence interval (CI) [0.76-0.95], p=.004. In an Analysis of 18 studies reporting race categories, NH-Black patients were significantly underrepresented (OR 0.50, 95% CI [0.45-0.54], p<.001), while Asian patients were overrepresented (OR 2.81, 95% CI [2.64-2.99], p<.001). In the four studies reporting ethnicity, Hispanic patients were also significantly underrepresented (OR 0.69, 95% CI [0.61-0.78], p<.001).

Conclusions: In clinical trials, performed in North America and Europe mainly, leading to FDA approvals for gynecologic malignancies - NH-Black and Hispanic patients are significantly underrepresented compared to NH-White participants when enrollment is benchmarked to the U.S. female population with gynecological cancer. These trials do not adequately reflect the U.S. populations diagnosed with these malignancies. Enrollment strategies to increase diversity are urgently needed to ensure clinical trial results are equitable and applicable across all populations. Efforts from the American Society of Clinical Oncology, the Association of Community Cancer Centers, and the Gynecologic Oncologic Group / Society of Gynecologic Oncology Inclusion, Diversity, Equity and Access initiative provide a comprehensive framework for achieving this goal.