Outcomes with Avelumab Maintenance Treatment for Advanced Urothelial Cancer in a US Patient Cohort

BACKGROUND: This study describes treatment patterns and clinical outcomes in patients with advanced urothelial carcinoma (aUC) in the US following the approval of avelumab for first-line maintenance treatment. METHODS: This retrospective cohort study used deidentified patient data from the Tempus database. Eligible patients had completed first-line systemic anticancer treatment for aUC between July 2020 and March 2023. RESULTS: In total, 974 eligible patients were identified; most (72%) were male. Median age at diagnosis was 70 years. Among patients who completed first-line platinum-based chemotherapy (644 [66%]), 574 (89%) had no evidence of disease progression. Of 219 patients who received first-line maintenance, 135 (62%) received avelumab. Median (95% CI) overall survival (OS) and progression-free survival (PFS) from avelumab maintenance start were 14.9 months (13.1-not estimable [NE) and 6.4 months (4.6-NE), respectively. Enfortumab vedotin (EV) was the most common second-line treatment after avelumab (70%). Median (95% CI) OS and PFS from second-line EV start were 11.6 months (6.1-NE) and 6.6 months (4.1-NE), respectively. CONCLUSIONS: Results provide insights into the impact of avelumab first-line maintenance treatment in patients with aUC in the US. Effectiveness data are consistent with previous findings, supporting the use of avelumab maintenance in patients without disease progression following first-line platinum-based chemotherapy. Second-line EV after progression on avelumab maintenance had similar effectiveness to results from other real-world studies.