Abstract B164: Trends in participant demographics in trials that led to FDA oncology approvals, 2017-2024

Abstract Clinical trials are vital for testing new treatments aimed at reducing cancer morbidity and mortality. Representation by racial and ethnic minorities and older adults has previously been reported as suboptimal in cancer trials, limiting the generalizability of the efficacy and safety results. In April 2022, the FDA issued a draft guidance to support trial sponsors to develop Diversity Plans with the goal of improving enrollment of participants from underrepresented racial and ethnic populations. However, there are no published analyses aimed at understanding the impact on oncology trials of the 2022 guidance and the subsequent 2023 Food and Drug Omnibus Reform Act (FDORA) requiring submission of Diversity Action Plans. To understand their impact on diversity of oncology trials that led to FDA approval, we analyzed these trials by gender, race, ethnicity and age from 2017 – 2024 using the FDA Drug Trial Snapshots for approved oncology drug trials. Key outcomes extrapolated include the proportion of participants by gender (male or female), race (White, Black, Asian), ethnicity (Hispanic) and age 65 years in all trials and deriving the proportion from among all enrolled participants in the trials for each year. We presented descriptive analyses in demographic trends from 2017 – 2024. Female enrollment in trials in which both male and female participants can be enrolled was 56% in 2017, but thereafter remains consistently low at 24 – 47% from 2018 – 2024. Black participant enrollment remained significantly low at 5% across years. The proportion of Asian enrollees remained consistent between 12 – 16% until 2023, where a sharp increase to 29% and 41% in 2023 and 2024, respectively was observed. This increase in Asian enrollment is likely due to an increase of oncology trials with trial sites in Asia. Prior to 2023, approximately 48% of trials included sites in Asia. However, the proportion of trials with sites in Asia increased to 71% and 81% in 2023 and 2024, respectively. Despite FDA guidance in 2016 strongly recommending the collection of ethnicity data, majority of trials did not disclose or collect Hispanic enrollment until 2020. Regardless, Hispanic enrollment remained low from 2020 – 2024 at 3 – 7%. Except in 2019 and 2022, proportion of patients 65 years remained below 50%, ranging from 31 – 49%, even though cancer is a condition of aging. Despite recent actions by the FDA to increase enrollment of diverse populations in clinical trials, diversity remains consistently low for underrepresented populations, particularly female, Black, Hispanic, and older adult populations. Recent increases in Asian enrollment are correlated with the movement of sponsors to conduct trials at sites in Asia. It is important to note that Asian populations are an already overrepresented minority. Overall, the impact of FDA policies on clinical trial representation is limited. Additional measures may be required to improve the enrollment of underrepresented populations to increase the generalizability of oncology clinical trial results. Citation Format: Shaurya Khanna, Carmen E. Guerra. Trends in participant demographics in trials that led to FDA oncology approvals, 2017-2024 abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr B164.