Real-World Evidence of Tumor and Patient Characteristics and Survival with Avelumab Maintenance after Chemotherapy for Advanced and Metastatic Urothelial Carcinoma.

Background: Despite the prospective randomized controlled JAVELIN Bladder 100 trial, no real-world evidence exists regarding tumor characteristics, adverse events (AEs), and survival of avelumab maintenance (AVM)-treated patients with partial/complete response or stable disease after previous platinum-based chemotherapy for advanced/metastatic urothelial carcinoma (mUC).

Methods: We relied on our institutional database to identify mUC patients who received AVM between January, 2021 and December, 2023. The main outcomes consisted of overall survival (OS) and progression-free survival (PFS) and were computed by Kaplan-Meier estimates. Stratification was performed according to programmed death ligand 1 (PD-L1) status.

Results: Overall, 24 AVM patients were identified at a median age of 71 (interquartile range [IQR]: 67-76) years, of which 67% were males. Of these, 63%, 21%, and 17% received AVM therapy for bladder cancer and upper tract urothelial carcinoma or both, respectively. PD-L1 status was positive in 45% of patients. During AVM treatment, AEs were observed in 33% of patients; however, they were limited to ≤2 grade AEs. At a median follow-up of eight (IQR 4-20) months, 71% of patients had progressed under AVM with median PFS of 6.2 months (confidence interval [CI]: 3.2-18.2). Median OS was 13.4 (CI: 6.9 - not reached [NR]) months. One-year OS after AVM was 52%. In PD-L1-positive patients, median PFS and OS were 6.4 (CI: 2.7 - NR) months and 13.4 (CI: 7.7 months - NR), respectively.

Conclusions: AVM is associated with moderate AE rates. Despite similarities in baseline characteristics compared to trial-selected JAVELIN Bladder 100 mUC patients, AVM resulted in longer/similar PFS but significantly shorter OS in real-world setting.