Clinical outcomes of black versus non-Hispanic white women with stage IV breast cancer treated with sacituzumab at Emory.

Abstract

e13141 Background: Black women (BW) experience higher rates of advanced breast cancer and the aggressive triple negative subtype compared to Non-Hispanic White women (NHW).Yet, Black participants are notably underrepresented in clinical trials. Sacituzumab govitecan (SG) is an antibody-drug conjugate (ADC) approved for hormone receptor-positive (HR+), HER2-negative breast cancer and is the first ADC approved for metastatic triple negative breast cancer (mTNBC). Black participants comprised < 5% in the clinical trials that led to SG's approval, leaving gaps in our understanding of this population. To address this, we aimed to compare baseline characteristics, treatment outcomes, and toxicity profiles between BW and NHW with metastatic breast cancer (mBC) treated with SG at an urban tertiary care institution. Methods: BW and NHW with mBC treated with SG at Emory University between 2019 and 2024 were retrospectively evaluated. Descriptive statistics were generated for all patient characteristics. Univariate analyses and a multiple logistic regression model were used to assess the effect of race on clinical response, duration on therapy, dose reductions, and toxicities. Progression free survival was assessed using Kaplan Meier analysis. Results: Eighty-four women with mBC treated with SG were included [BW, n = 54 (64%) and NHW, n = 32 (38%)]. 70% of patients had TNBC whilst the remaining had HR+, HER2 - mBC. Demographics were similar among groups, including breast cancer subtypes, mean age at diagnosis of metastatic disease, and the number of prior lines of therapy received. Thirty-eight women had also received Trastuzumab Deruxtecan, another ADC, at some point during their treatment course (BW, n = 26 and NHW, n = 14). The median duration on SG was similar across racial groups. There was no difference in complete or partial response to SG between races; however, NHW had higher rates of stable disease (56% vs 14%, p = .025), while BW had higher rates of disease progression (50% vs 16%, p = .025). The median progression free survival for the entire cohort was 3.9 months. The most common non-hematologic toxicities—diarrhea, nausea, and fatigue—did not differ between races. Neutropenia was the most common hematologic toxicity, with Grade 3-4 neutropenia being comparable across races. Dose reductions, dose delays, and the use of growth factor support were similar across groups. Conclusions: Our institutional data demonstrate that BW had higher rates of disease progression on SG for mBC, while NHW had higher rates of stable disease. Toxicity profiles with SG were similar across races. The inclusion of diverse patients in clinical trials, including real-world analyses, is essential to uncover and address potential disparities in response and toxicity for patients receiving ADCs.