Avelumab maintenance in advanced urothelial carcinoma: real-world data from Northern Spain (AVEBLADDER study)

Background Before the incorporation of enfortumab vedotin with pembrolizumab, the standard of care for patients with locally advanced or metastatic urothelial carcinoma who do not progress after platinum-based chemotherapy was avelumab maintenance therapy, as demonstrated by the JAVELIN 100 trial. However, real-world European data remain scarce. Patients and Methods AVEBLADDER is a retrospective study conducted at 14 hospitals in Northern Spain, including patients with locally advanced or metastatic urothelial carcinoma diagnosed between January 2021 and June 2023. Outcomes of overall survival (OS) and progression-free survival (PFS) were analyzed for patients treated with platinum-based chemotherapy, with and without subsequent avelumab maintenance therapy. non-avelumab patients. Median PFS was 11.33 months (95% CI: 10-13.6) with avelumab and 6.43 months (95% CI: 6-7.6) without. One-year OS probabilities were 81.6% vs. 45.6% (p < 0.001) in the avelumab and non-avelumab groups, respectively. No unexpected toxicities were reported. Conclusions Despite proven survival benefits, avelumab uptake in real-world practice is limited by barriers like access, reimbursement, and awareness. These findings align with JAVELIN 100 and underscore the need for further real-world studies to address treatment disparities.