Real-world survival outcomes with single-agent erdafitinib (Erda) in patients (pts) with advanced urothelial carcinoma (aUC) based on line (L) of therapy and prior enfortumab vedotin (EV) treatment (Rx).

Abstract

694 Background: Erda, a pan fibroblast growth factor receptor (FGFR) inhibitor, has been approved since 2019 for pts with aUC harboring FGFR3 alterations. However, data on uptake and outcomes of erda, including its effectiveness before and after EV, are limited. We aimed to evaluate real-world survival outcomes and Rx patterns of single-agent erda in pts with aUC in a large database. Methods: This study used the US-based, electronic health record-derived deidentified Flatiron Health Research Database. Eligibility: diagnosis of aUC between 1/13/2013 and 11/4/2024 and receipt of single-agent erda. Pts on clinical trials were excluded. The data cutoff date was 6/30/2025. The L numbers for single-agent erda were summarized using frequency and percentages. Time to next therapy (TTNT) was defined as time from erda initiation to the next L of Rx or death and censored at the lost to follow up. Overall survival (OS) was defined as time from the erda initiation to death and censored at the lost to follow up. For stratified analysis, pts who received any EV-containing Rx before or after erda were included. Kaplan-Meier method was used to estimate median TTNT and OS, and their 95% confidence intervals (CIs). Results: Of 15,236 pts with aUC in the dataset, 180 who received single-agent erda were eligible and included in the analysis. Start date for erda was between 5/1/2019 and 5/15/2025. Median age was 73 years (IQR 66 – 78); most were White non-Hispanic (73%), male (67%), and treated in community practice (78%). Erda was given in 2L for 36% of pts and in 3L for 32%. At a median follow up of 35.3 months, 76% of pts died, median TTNT was 5.3 mo (95% CI 4.9 – 6.2) and median OS was 9.1 mo (95% CI 6.9 – 12). Median TTNT and OS by L of Rx are summarized in Table. Among 180 pts, 107 also received EV: 45 received erda followed by EV and 62 received EV followed by erda. Median TTNT and OS was 5 mo (95% CI 4.5 - 7.9) and 17 mo (95% CI 14 – 21) when pts received erda followed by EV and was 4.9 mo (95% CI 3.8 - 6.2) and 5.4 mo (95% CI 4.9 – 9.7) when EV followed by erda. Conclusions: In this large real-world cohort, single-agent erda was mostly used in 2L-3L and associated with modest survival outcomes. Erda demonstrated sustained effectiveness regardless of L of therapy and prior EV exposure. These findings may help answer sequencing questions in clinical practice and help provide survival estimates for clinical trial design. Median TTNT and OS by line of Rx in pts with aUC receiving single-agent erda. Line of Rx Number of pts, n (%) Median TTNT (mo) (95% CI) Median OS (mo) (95% CI) 1 21 (12) 6.3 (3.5, 15) 21 (6.4, -) 2 64 (36) 5.6 (5.1, 7.5) 12 (8, 19) 3 57 (32) 5 (4.4, 7.2) 7.1 (5.8, 11) 4 24 (13) 4.4 (3, 15) 6.4 (4.3, -) 5 8 (4) 2.5 (1.3, -) 2.5 (1.6, -) 6 5 (3) 2.9 (1.9, -) 5.6 (5.1, -)