Abstract Background Healthcare continues to suffer from a one-size-fits-all, trial-and-error model. Precision medicine seeks individualized care but requires clinical trial cohorts that mirror patient populations to detect differences in treatment response. Systematic assessments of trial cohort representativeness remain sparse; most studies are narrow. This study evaluates whether recent efforts, including the US FDA’s Drug Trial Snapshots Program, have improved demographic representation in pivotal trials across disease areas. Methods We analyzed Drug Trial Snapshots Program data covering 341 Phase III clinical trials supporting drug approvals between 2017 and 2023. We compared enrollment of Asian, Black, Hispanic, and White participants with US Census data using chi-squared tests; assessed trends with regression; and examined patterns by disease area, regulatory designation, and US recruitment. Results Here, we show that only 6% of pivotal clinical trials achieve enrollment aligned with the distribution of the four largest racial and ethnic groups in the US population. Enrollment of Black and Hispanic participants decreases over time, whereas that of Asian and White participants increases and remains stable, respectively. Trials based in the US include more Black participants, while trials with Breakthrough Therapy designation (which expedites development and review of drugs for serious or life-threatening conditions) show more balanced enrollment across groups. Conclusions Persistent imbalances in trial enrollment limit the delivery of precision medicine. Trial location and regulatory designations influence who is included. Earlier planning of trials and more strategic site selection improve the potential for future treatments to serve individuals from all racial and ethnic groups.
Zaaijer et al. (Fri,) studied this question.