Abstract PD1-03: The generalizability and transportability of FDA drug approvals in breast cancer from 2010 - 2025

Abstract INTRODUCTION: Historical migration patterns, systemic inequities, and biological factors such as genetic polymorphisms and microbiome diversity all contribute to varied treatment responses among different racial and ethnic groups. Dr. Yedjou’s “Health and Racial Disparity in Breast Cancer” reported that while there is only a 2.6% difference in the incidence rate of breast cancer between White and Black women, Black women are 42% more likely to die from breast cancer than White women. While there may be other factors that play a role in these statistics, current trial designs often fail to account for the differences present amongst race and ethnic groups, leading to regulatory approvals based on non-generalizable data. Generalizability refers to the ability to infer the average treatment effect from a sample to the entire target population. In order to further evaluate the generalizability of breast cancer drugs from the past decade (2015 to 2025), we reviewed the FDA’s “Oncology (Cancer) /Hematologic Malignancies Approval Notifications” webpage. METHODS: Between February 3, 2015 and January 27, 2025, we identified 33 breast cancer drug approvals and used the DRIVE calculator to evaluate the generalizability of drug approval for target populations for which they will be used. Each study was examined for the inclusion of demographic data and reporting of the racial/ethnic composition of its participants. Following this review, a DRIVE score, ranging from 0 to 5, was assigned to each study, with a designation of “0x” or “0*” given if the racial/ethnic data was not reported or was reported separately, respectively. We have previously defined a minimum DRIVE score of 3 as the benchmark for clinical excellence and relevance based on racial representation. Demographic information was recorded as it was available at the time of abstract submission, based on the NCI clinical trial results section. RESULTS: A total of 9 breast cancer clinical trials met the criteria for clinical trial excellence, revealing an overwhelming lack of generalizability within these FDA drug approvals. Over this ten year period, 24 clinical trials failed to meet the minimum requirements for clinical trial excellence. The full score breakdown is as follows: 3 received a score of 0x, 2 received a score of 0, 5 received a score of 0*, 13 received a score of 1, 1 received a score of 2, 8 received a score of 3, 1 received a score of 4, and 0 received a score of 5. CONCLUSION: Our findings reveal that 9 out of 33 of the clinical trials associated with FDA approvals met the minimum criteria for clinical trial excellence. Although all the breast cancer drugs evaluated have received FDA approval, 72.5% do not accurately represent the intended patient populations. This lack of representation exacerbates disparities, particularly among minoritized populations, and leaves critical gaps in understanding potential adverse reactions or side effects. The aim of this analysis is to emphasize the need to minimize therapeutic misconceptions, the assumption that approved drugs with promising clinical trial data have demonstrated effectiveness across all patient populations. A clear understanding of the DRIVE Score Ranking and its purpose can assist clinicians and patients identify which drugs are supported by generalizable and transportable data, ultimately guiding more inclusive and equitable clinical research practices. For these reasons, we advocate for the exclusive use of trials meeting the minimum standards for “clinical trial excellence” as the basis of FDA approvals ensuring equitable benefits for all patients. Citation Format: M. N. Birhiray, S. Ranger, R. E. Birhiray. The generalizability and transportability of FDA drug approvals in breast cancer from 2010 - 2025 [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PD1-03.