4CPS-007 Efficacy and safety of avelumab in patients with locally advanced or metastatic urothelial carcinoma

<h3>Background and Importance</h3> The majority of patients with metastatic urothelial carcinoma experience disease progression within 9 months of initiating chemotherapy. This has led to the exploration of maintenance therapy aimed at prolonging the chemotherapy response for as long as possible. Avelumab, a monoclonal antibody targeting the programmed death-ligand 1 (PD-L1), is approved for first-line maintenance treatment in adult patients with locally advanced or metastatic urothelial carcinoma (UC) who have not progressed after platinum-based chemotherapy. <h3>Aim and Objectives</h3> To determine the efficacy and safety of avelumab in patients with metastatic bladder cancer. <h3>Material and Methods</h3> This was a retrospective, observational, single-centre study conducted at a tertiary care hospital over 39.2 months, from January 2021 to March 2024. Efficacy endpoints included progression-free survival (PFS) and overall survival (OS), while safety endpoints included adverse events and their severity. The statistical analysis was performed using R Commander 2.9–1. <h3>Results</h3> A total of 30 patients were included with the following characteristics: 73% were male, with a median age of 73 years (range 40–87) and baseline ECOG performance status was 0 (47%) or ≥1 (53%). In terms of first-line induction chemotherapy, 30% of patients received Gemcitabine-Cisplatin, 67% received Gemcitabine-Carboplatin, and 3% received both. 90% of patients achieved a complete response (CR) or partial response (PR) to prior platinum-based therapy and 10% had stable disease (SD). Additionally, 43% of patients had visceral metastases, and 23% of tumours expressed PD-L1. The median OS was 21.3 months (95% confidence interval (CI): 10.4-not reached (NR)), and the median PFS was 4.8 months (95% CI: 3.3–13.8). 23% of patients experienced adverse events of any-grade related to the medication, including fatigue, dysuria, and urinary tract infection. Grade 3–4 adverse reactions were observed in 6.7% of patients, and treatment administration was delayed in 10% of cases. <h3>Conclusion and Relevance</h3> Clinical practice outcomes demonstrate efficacy results comparable to those obtained in the pivotal JAVELIN Bladder 100 trial, which reported a median OS of 22.1 months and a PFS of 3.7 months. Regarding safety, the toxicity profile in our study was better than that observed in the pivotal trial (98% adverse events). These findings support the use of Avelumab in clinical practice, highlighting the importance of its funding for these patients. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest