Response to First-Line Chemotherapy Predicts Response to Maintenance Avelumab Therapy in Japanese Patients With Advanced Urothelial Carcinoma.

Abstract

Objectives: The association between the response to first-line chemotherapy and maintenance of avelumab remains unclear. We identified factors associated with the response to avelumab in patients with advanced urothelial carcinoma using real-world data.

Methods: We retrospectively enrolled 100 patients with advanced urothelial carcinoma treated with maintenance avelumab therapy between March 2021 and April 2024 at Nagoya University and nine affiliated hospitals. The complete/partial-response group was defined as patients with complete response or partial response as the best response to first-line chemotherapy. The stable disease group was defined as patients with stable disease as the best response to first-line chemotherapy.

Results: Seven patients (7.0%) achieved complete response, 65 (65.0%) achieved partial response, and 28 (28.0%) achieved stable disease as the best response to first-line chemotherapy. Regarding avelumab therapy, the complete/partial-response group had significantly better progression-free survival than the stable disease group (median: 11.1 vs. 3.2 months, p < 0.001). In multivariate analyses, the best response to first-line chemotherapy was the only independent risk factor for progression-free survival (hazard ratio = 1.844, 95% confidence interval = 1.002-3.394; p = 0.049). Overall survival was significantly shorter in the stable disease group than in the complete/partial-response group (median: 14.1 months vs. not reached, p < 0.001). Multivariate analyses revealed significant associations between poor overall survival and performance status (hazard ratio = 2.175, 95% confidence interval = 1.030-4.592; p = 0.042) and the best response to first-line chemotherapy (hazard ratio = 4.174, 95% confidence interval = 1.975-8.824; p < 0.001).

Conclusions: The best response to first-line chemotherapy may predict the clinical outcome of patients with advanced urothelial carcinoma treated with avelumab.