Real-world data of enfortumab vedotin in patients with advanced urothelial cancer in Spain: The ENFANTS-GUARD study.

700 Background: Urothelial cancer (UC) is the fifth most common cancer in Spain. Advanced UC (aUC) is an aggressive disease with a high mortality rate. Enfortumab vedotin (EV) has been recently approved in Spain for the treatment of adult patients (pts) with aUC, although real-world data remain limited. We aim to describe clinical characteristics, treatment, outcomes and safety of EV treatment in routine practice. Methods: This retrospective observational study included pts with aUC who received EV across 17 hospitals in Spain. Demographic, clinical, treatment-related (efficacy and safety) and healthcare resource utilization data were collected. Progression-free survival (PFS), overall survival (OS) and time to treatment failure (TTF) were measured from EV initiation. Survival was estimated using the Kaplan–Meier method. Investigator-assessed observed response rate (ORR) was assessed for evaluable pts with scans after ≥1 cycle EV. Adverse events (AEs) were recorded and graded by CTCAE 5.0. Hospital admissions during EV treatment were collected. Results: A total of 195 pts were included. Median age was 71 years, 76.9% were male. 49.7% had localized disease at diagnosis with a median time to metastasic progression of 17.9 months. The primary tumor site was bladder in 82.1%, and upper urinary tract in 15.9%. 76.3% had pure urothelial, 22.2% variant differentiation and 3 (1.5%) non-urothelial carcinoma. ECOG PS was 0,1 and ≥2 in 25.1%, 63.6% and 11.3% pts, respectively. Patients received a median of 2 prior lines of systemic treatment. The most common immediate prior treatments were PD-1/L1 inhibitor monotherapy (41.0%) and chemotherapy (13.9%), while 27.7% received these in combination or as maintenance. Median follow-up was 34.4 months. Median PFS, OS and TTF were 7.4 [5.87-8.89], 12.8 [11.2-14.3] and 6.2 [5.54-7.97] months, respectively. ORR was 52.1%. EV related AEs occurred in 68.7% of pts, with ≥ grade 3 in 20.9%. Peripheral sensory neuropathy and rash were the most frequent AEs. 29.7% pts required hospitalization during EV treatment, with a median stay of 7 days. Baseline characteristics are summarized in Table 1. Conclusions: In this multicenter cohort, EV demonstrated efficacy and safety consistent with clinical trials, supporting its role as a standard option for previously treated patients with aUC. Despite the overall clinical burden, EV achieved meaningful disease control with favorable ORR and TTF outcomes in routine practice. Baseline characteristics. Characteristics (n) Results [n(%)] Current/former Smokers (195) 32(16.4%) Bellmunt risk (195) = 0 = 1 = 2 = 3 32 (20.3%)82 (51.9%)38 (24.1%)6 (3.8%) Liver metastasis (%) (195) 43 (22.0%) Exclusive lymph node involvement (192) 38 (19.8%) FGFR2/3 mutation (64) 12(18.8%) Pts with prior response to platinum chemotherapy (194) 100 (51.5%) Pts with prior response to immunotherapy (193) 7 (3.6%)