Real-world first-line treatment patterns and outcomes in patients with locally advanced or metastatic urothelial carcinoma in the United States.

e23287 Background: Historically, cisplatin-containing chemotherapy has been the recommended first-line (1L) treatment for locally advanced or metastatic urothelial carcinoma (la/mUC). For those ineligible for cisplatin due to poor performance status, impaired renal function, or comorbidities, alternative choices include carboplatin-based chemotherapy and PD-1/L1 inhibitors. This study aimed to describe real-world treatment patterns and overall survival (OS) among US Medicare patients with la/mUC receiving 1L therapy. Methods: This retrospective study used Medicare fee-for-service claims data from 2015 through 2022 to identify patients diagnosed with la/mUC who received systemic treatment. Initiation of 1L therapy was the index date for study inclusion; treatment patterns and OS were assessed until end of data availability, discontinuation of health plan enrollment, or death. OS was estimated using the Kaplan–Meier approach, and a log-rank test was used to compare OS across the following 1L treatment groups: platinum-based chemotherapy (PBC; cisplatin- and carboplatin-based), non-PBC monotherapy, and PD-1/L1 inhibitor monotherapy. Hazard ratios (HRs) were estimated across groups using Cox proportional hazards models adjusting for baseline characteristics. Results: Of 13,104 patients included in this analysis, 77.5% were male, and mean (SD) age was 76.2 (7.5) years. The most commonly observed 1L treatment categories were PBC (cisplatin-based, 19.7%; carboplatin-based, 28.4%), PD-1/L1 inhibitors (34.8%), non-PBC (13.7%), and other combination therapies (2.9%). Common comorbidities included renal disease (39.9%), chronic obstructive pulmonary disease (36.1%), and diabetes (32.2%). Compared with patients in the cisplatin cohort, patients in other cohorts had higher NCI Comorbidity Index scores. Median duration of 1L treatment was 3.5 months for PD-1/L1 inhibitors, 3.2 months for carboplatin, 3.0 months for cisplatin, and 2.0 months for non-PBC. Median OS was longest with cisplatin (17.0 months; IQR: 7.8–51.9), followed by non-PBC (14.7; 5.5–39.7), carboplatin (10.5; 4.9–25.1), and PD-1/L1 inhibitors (9.4; 2.8–27.9). In the adjusted Cox model, all treatment groups had statistically significantly higher hazards of death compared with cisplatin, with an HR (95% CI) of 1.50 (1.41, 1.59; P< 0.001) for PD-1/L1 inhibitors, 1.38 (1.30, 1.46; P< 0.001) for carboplatin, and 1.11 (1.03, 1.19; P= 0.007) for non-PBC. Conclusions: In this large retrospective study of US Medicare patients from 2015–2022 with la/mUC, PBC was the most common 1L treatment, followed by PD-1/L1 inhibitors and non-PBC. While cisplatin-treated patients had longer OS than patients in other groups, treatment durations were short, and OS was generally poor across regimens. These findings highlight an unmet need for more effective 1L therapies in la/mUC.