Outcomes of Patients with Advanced Urothelial Carcinoma after Anti-programmed Death-(ligand) 1 Therapy by Fibroblast Growth Factor Receptor Gene Alteration Status: An Observational Study

Background: Clinical outcomes of anti-programmed death (ligand) 1 (anti-PD-[L]1) therapy in patients with locally advanced or metastatic urothelial carcinoma (mUC) and fibroblast growth factor receptor alterations (FGFRa+) remain unclear; recent studies have reported either comparable or poorer outcomes versus patients without FGFR alterations (FGFRa-). Objective: To analyze the outcomes of patients with mUC and any FGFRa (mutations or fusions) who received anti-PD-(L)1 therapy. Design, setting, and participants: In this noninterventional, retrospective, multicenter study, clinical practice data were collected from FGFRa+/- patients who received prior immunotherapy between May 2018 and July 2019. Outcome measurements and statistical analysis: Investigator determined overall response rate (ORR), disease control rate (DCR), and overall survival (OS) were assessed in multivariate and unadjusted analyses. Results and limitations: Ninety-four patients (66% men; median age, 63 yr) with mUC and known FGFR status were included; 38 (40%) were FGFRa+ and 56 (60%) were FGFRa-. In FGFRa+ versus FGFRa- patients who received any line of anti- PD-(L)1 therapy (n = 92), ORR, DCR, and OS were 16% versus 26%, 29% versus 52% (relative risk: 1.14 [95% confidence interval {CI}, 0.92-1.40]; p = 0.3), and 8.57 ver-sus 13.2 mo (hazard ratio [HR]: 1.33 [95% CI, 0.77-2.30]; p = 0.3), respectively. A multivariate analysis provided some evidence supporting shorter OS in FGFRa+ ver-sus FGFRa- (any line of anti-PD-L[1] therapy; HR: 1.81 [95% CI, 0.99-3.31];