e23278 Background: Capecitabine (cap) is approved for the treatment of breast and colorectal cancer and is used off-label to treat other solid malignancies. Approved dosing varies by indication and concurrent therapies, and the initial dose of cap may be modified empirically based on different patient characteristics. Race/ethnicity have been used by some providers as factors in prescribing patterns. However, the tolerability of cap among patients of different racial/ethnic backgrounds is unknown. Here, we present an updated analysis outlining the tolerability of cap among patients of different racial/ethnic groups. Methods: We performed a retrospective, multicenter study that included patients treated with cap monotherapy, concurrent with other chemotherapy, or concurrent with radiation at three sites in Massachusetts between 2017-2021. Patients were excluded if race/ethnicity data were not available. Data on cap dose, required dose reductions/treatment discontinuation, and adverse events (AE) were collected. Dose Intensity (DI) was calculated (Total administered cap dose during the treatment period (mg)/Recommended cap dose (mg/m2)*BSA (m2)). DI was compared across groups using non-parametric Kruskal-Wallis tests. The frequency of AE leading to dose reduction/discontinuation was compared across groups using chi-square tests. Results: 239 patients were included as outlined in Table 1. Median DI (IQR) for White patients was 0.95 (0.77,1.00), for Asian patients 1.00 (0.86,1.00), for Black/African American patients 0.88 (0.67,1.00), and for patients of other race 1.00 (0.79,1.00). There was no statistically significant difference across racial groups (p = 0.233). Median DI (IQR) for Hispanic/Latino patients was 0.84 (0.73,1.00) and for non-Hispanic/Latino patients 0.96 (0.77,1.00). There was no statistically significant difference between ethnicity groups (p = 0.562). The most commonly experienced AE included Hand Foot Syndrome, Fatigue, Diarrhea, and Nausea/Vomiting (Table 1). There was no statistically significant difference in AE frequency between groups. Conclusions: Our study shows no significant difference in the tolerability of cap between patients of different racial/ethnic groups, nor did we find any difference in the predominant AE. While this study is limited by the fact that it is retrospective and small, the results reinforce the importance of considering the entire clinical context when selecting a treatment dose and avoiding empiric dose reductions based on factors such as race/ethnicity. [Table: see text]