Real-World Treatment Patterns, Sequencing, and Outcomes in Patients with Locally Advanced or Metastatic Urothelial Carcinoma Receiving Avelumab First-Line Maintenance in the United States.

For patients with locally advanced/metastatic urothelial carcinoma (la/mUC), first-line (1L) treatment with platinum-based chemotherapy (PBC) followed by avelumab 1L maintenance (1LM) is a recommended therapy per treatment guidelines in patients without disease progression. However, contemporary real-world (rw) data among patients receiving this treatment are necessary to understand clinical outcomes and optimal treatment sequencing. This retrospective cohort study analyzed rw treatment patterns and clinical outcomes, including overall survival (rwOS) and progression-free survival (rwPFS), in patients with la/mUC receiving avelumab 1LM. From the Flatiron Health database, 214 patients who received avelumab 1LM following 1L PBC were included. From the start of avelumab 1LM, median rwOS was 23.8 months (95% CI: 18.2-not estimable [NE]) and median rwPFS was 5.1 months (95% CI: 4.1-7.0). A total of 96 patients received second-line (2L) therapy, with 53 receiving enfortumab vedotin (EV). From the start of 2L EV, median rwOS was 11.2 months (95% CI: 6.8-NE) and median rwPFS was 4.9 months (95% CI: 3.9-8.8). Treatment patterns and clinical outcomes in this study align with guidelines and outcomes observed in the JAVELIN Bladder 100 and EV-301 clinical trials and other rw studies, supporting the use of 1L PBC followed by avelumab 1LM and 2L EV for eligible patients.