Race/ethnicity reporting and representation in clinical trials presented at plenary and late-breaking abstract sessions at the American society of hematology (ASH) from 2014 to 2024

Abstract Diversity of clinical trial participants helps ensure generalizability of results to real world patient populations. Despite significant efforts to address problems of health equity, minority populations remain historically underrepresented in clinical trial enrollment. In 2021, ASH launched its Diversity, Equity, and Inclusion (DEI) Initiative which aimed to increase minority enrollment in clinical trials. This study evaluates the frequency of race/ethnicity reporting and proportional race/ethnicity representation in trials presented at ASH plenary and late-breaking abstract sessions. We reviewed ASH plenary sessions and late-breaking abstracts from 2014 through 2024 to identify clinical trial presentations. These clinical trials were identified using the National Institutes of Health trials registry (ClinicalTrials.gov). Trial characteristics and race/ethnicity reporting were abstracted from primary report publications or ClinicalTrials.gov if the reporting was not included in the primary report. When an ASH plenary session involved multiple trials, each trial was included in the analysis. US population-based cancer estimates were derived from the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) and US Census databases. Age-standardized incidence and mortality rates, adjusted to the 2000 US standard population by race, were used to estimate 5-year average incidence and mortality rates from 2017 to 2021. Clinical trials on hematologic diseases not listed in SEER database were excluded. Disparity in enrollment was determined by calculating enrollment incidence disparity (EID), enrollment mortality disparity (EMD), enrollment incidence ratio (EIR), and enrollment mortality ratio (EMR). We identified 28 clinical trials with 15,460 participants presented at ASH plenary and late-breaking abstract sessions from 2014-2024. Race was reported in 17 (61%) trials and both race and ethnicity were reported in 11 (39%) trials. Between 2014 and 2019 vs 2021 and 2024, the proportion of trials reporting race or both race and ethnicity increased 59% to 67% and 36% to 50%, respectively. Overall, White, Hispanic, Black, and Asian patients represented 75.1%, 10.8%, 5.7%, and 4.1% of the trial participants, respectively. For the total study period, relative enrollment measured by EID, EIR, EMD, and EMR were unfavorable for Black patients compared with White. For trials that reported ethnicity, the EID, EIR, and EMD were unfavorable for Hispanic patients compared with White. Between 2014 and 2019 vs 2021 and 2024, Black (43.9% vs 35.9% of expected) and Hispanic (49.0% vs 40.4% of expected) patients remained underrepresented compared to White (124.2% vs 127.8% of expected) and Asian (96.0% vs 98.1% of expected) patients. Since the 2021 ASH DEI, reporting of race and ethnicity in landmark clinical trials presented at ASH plenary sessions and late-breaking abstracts has improved. However, this has not translated to significantly improved enrollment of Black and Hispanic participants. Continued policy action is needed to standardize race/ethnicity data collection and promote inclusive trial enrollment. Equitable representation is essential to reducing disparities in clinical outcomes.