Real-world data on avelumab in first-line maintenance therapy for advanced or metastatic urothelial carcinoma: the SOGUG-AVELUMAB RWD study.

Maintenance avelumab has shown improved overall survival compared to chemotherapy alone in first-line treatment of advanced urothelial carcinoma. This study evaluates real-world evidence of avelumab as first-line maintenance therapy in patients with locally advanced or metastatic urothelial carcinoma (la/mUC). This was a multicenter, observational, retrospective and prospective study conducted in 22 Spanish centers. Patients were selected based on existing medical records of those treated with avelumab as first-line maintenance therapy before initiating the study (retrospective data), and those who continued to receive avelumab until the end of treatment or end of study (prospective data). Endpoints included median progression-free survival (mPFS), median overall survival (mOS) when available, PFS rate at 12 months (PFS12) and safety profile. Of the 125 patients enrolled, 113 were evaluable. The median follow-up of avelumab treatment was 10.7 months. Disease progression was the main reason for discontinuation in 70 (61.9%) patients, with a median time to progression disease of 6.8 months. The survival probability was 21.4% for mPFS, with progression disease or death in 67.3% of patients; 44.9% for PFS12, with progression disease or death in 52.2% of patients; and 92.2% for mOS, with death in 2.6% of patients. Adverse events (AEs) were reported in 12.4% of patients; 65.0% of AEs not related to avelumab, and 35.0% were serious (SAEs). The real-world results support the effectiveness and manageable safety profile of avelumab as first-line in stage IV urothelial carcinoma. Further prospective studies with longer follow-up are warranted to confirm these findings.