e18501 Background: Cancer clinical trials based in the United States (US) have lacked adequate representation of racial and ethnic minorities, the elderly, and women. Pivotal clinical trials leading to United States Food and Drug Administration (FDA) approval are often multi-national trials and may also lack generalizability to underrepresented populations in the United States. We determined the racial, ethnic, age, and sex enrollment in pivotal trials relative to the US cancer population. Methods: We reviewed the FDA’s Drug Approvals and Databases for novel and new use drug approvals for breast, colorectal, lung, and prostate cancer indications from 2008 through 2020. Drugs@FDA was searched for drug approval summaries and FDA labels to identify clinical trials used to justify clinical efficacy that led to FDA approval. For eligible trials, enrollment data were obtained from FDA approval summaries, FDA labels, ClinicalTrials.gov, and corresponding journal manuscripts. Enrollment Fraction (EF) was calculated as enrollment in identified clinical trials divided by 2017 SEER cancer prevalence. All data sources were publicly available. Results: From 2008 through 2020, 60 drugs received novel or new use drug approval for breast, colorectal, lung, or prostate cancer indications based on 66 clinical trials with a total enrollment of 36,830. North America accounted for 9,259 (31%) enrollees of the 73% of trials reporting location of enrollment. Racial demographics were reported in 78% of manuscripts, 66% of ClinicalTrials.gov pages, and 98% of FDA labels or approval summaries. Compared with a 0.4% enrollment fraction among White patients, lower enrollment fractions were noted in Hispanic (0.2%, odds ratio [OR] vs White, 0.46; 95% confidence interval [CI], 0.43 to 0.49, P< 0.001) and Black (0.1%, OR 0.29; 95% CI 0.28 to 0.31, P< 0.001) patients. Elderly patients (age ≥ 65 years) were less likely than younger patients to be enrollees (EF 0.3% vs 0.9%, OR 0.27; 95% CI 0.26 to 0.27, P< 0.001) despite accounting for 61.3% of cancer prevalence. For colorectal and lung cancer trials, females were less likely than males (EF 0.7% vs 1.1%, OR 0.66; 95% CI 0.63 to 0.68, P< 0.001) to be enrolled. Conclusions: Black, Hispanic, elderly, and female patients were less likely to enroll in cancer clinical trials leading to FDA approvals from 2008 to 2020. Race and geographic enrollment data were inconsistently reported in journal manuscripts and ClinicalTrials.gov. The lack of appropriate representation of specific patient populations in these key clinical trials limits their generalizability. Future efforts must be made to ensure equitable access, representation, and reporting of enrollees that adequately represent the US population of patients with cancer.
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