Sociodemographic disparities in treatment (tx) patterns and clinical outcomes among real-world patients (pts) with locally advanced/metastatic urothelial carcinoma (la/mUC) in the US.

707 Background: Sociodemographic disparities in la/mUC pt population include worse survival outcomes observed among certain pt subgroups. This study evaluates disparities among la/mUC pts receiving systemic therapies overall and those initiating an antibody drug conjugate in the real world. Methods: This descriptive, retrospective cohort study used US Flatiron Health electronic health record–derived de-identified database. Pts aged ≥ 18 yrs were grouped into cohorts C1 (all pts with la/mUC) and C2 (2L+ sacituzumab govitecan [SG] or 1L+ enfortumab vedotin [EV]) with tx initiation on/after Jan 2017 and Dec 2019, respectively; data cutoff for both cohorts was July 2024. Pt demographics and clinical outcomes (overall survival [OS] and time to tx discontinuation [TTD]) were calculated overall and by race. Socioeconomic status (SES) index was calculated using Yost index score (1 = lowest category; 5 = highest). Predictors of survival were assessed using Cox proportional hazards model. Results: C1 comprised 5102 pts. Most were White (68%) followed by Other race (11%), Black (5%), and Asian (1%); 15% were missing race. The racial distribution among C2 (N = 767) was similar to C1. Median age across C1 and C2 was similar (74 and 73 yrs, respectively), with Black pts being the youngest in both cohorts (median ages in C1 and C2: 70 and 65 yrs, respectively). Across both cohorts, Black and Asian pts, respectively, had the greatest proportion of pts in the lowest SES index group (C1: 36.7% and 13.3%; C2: 43.6% and 22.2%). In C1, median TTD (95% CI) was 3.0 (2.8-3.0) mos and was similar across all races. In C2, median TTD was higher for Asian (6.8 [4.2-NR] mos) and Black pts (6.5 [2.3-8.1] mos) and lowest for Other race (3.1 [1.9-4.3] mos). Median OS (95% CI) was 13.3 (12.6-13.9) mos in C1 and 11.9 (10.4-12.9) mos in C2. In both C1 and C2, Asian pts had the longest survival (median OS: 25.2 [11.9-41.9] and 14.0 [9.3-NR] mos, respectively) and Black pts had the shortest survival (median OS: 11.2 [9.2-15.9] and 11.4 (6.9-20.5] mos, respectively). Exploratory Univariate Cox modeling (limited by small sample size) suggested older age, history of smoking, treatment in community setting, de novo metastatic diagnosis, and ECOG score ≥ 2 are factors associated with low survival in C1 and only history of smoking and ECOG score ≥ 2 in C2. Conclusions: In this real-world study of treated pts with la/mUC, sample sizes, especially in C2, further research is needed to understand disparities and pt-centric factors that may impact tx decisions, TTD patterns, and reasons for discontinuation to define and address the unmet medical needs of these pts.