A Multicenter Retrospective Study of Avelumab First-Line Maintenance and Subsequent Therapies for Locally Advanced and Metastatic Urothelial Carcinoma: Subgroup Analysis of First-Line Dose-Dense Methotrexate, Vinblastine, Doxorubicin, and Cisplatin, and Gemcitabine Plus Cisplatin in the Japan AVElumab MAintenance and Continuous Treatment Study (JAVEMACS)

Avelumab maintenance therapy is approved in Japan for patients with aUC without progression after PBC. This report presents subgroup analysis data from the JAVEMACS chart review of avelumab maintenance in patients who received 1L ddMVAC and GC. This retrospective study reviewed medical charts of patients with aUC (February 2021–December 2023). Overall, 350 patients (ddMVAC, n = 32 and GC, n = 196) were included in the study. Baseline characteristics were balanced between the two PBC groups. Median duration from PBC start to avelumab start was 13.2 and 21.1 weeks; median overall survival (OS) was not reached (both groups), progression-free survival (PFS) was 12.0 and 7.4 months, and PFS2 was 27.6 and 21.3 months for the ddMVAC and GC groups, respectively. At data cutoff (June 2024), 25.0% of patients in the ddMVAC and 17.3% in the GC groups were ongoing avelumab treatment. Second-line treatments included EV (64.3% ddMVAC; 64.5% GC), pembrolizumab (21.4% ddMVAC; 8.3% GC), and PBC (14.3% ddMVAC and 21.5% GC). This real-world data from patients with aUC in Japan showed consistent OS patterns with avelumab maintenance across treatment subgroups vs. the overall population despite their inherent heterogeneity. Although patients were not resistant to PBC, 2L EV was more common than 2L PBC.