Clinical Outcomes With Immune Checkpoint Inhibitors in Patients With FGFR2/3, MTAP or ERBB2 Genomic Alterations in Advanced Urothelial Carcinoma

Background: FGFR2/3, MTAP and ERBB2 genomic alterations have treatment targets in advanced urothelial carcinoma (aUC). These alterations may affect tumor microenvironment and outcomes with immune checkpoint inhibitors (ICIs) in aUC. Patients and Methods: We identified patients with available genomic data in our multi-institution cohort of patients with aUC treated with ICI. Outcomes (observed response rate [ORR], progression-free and overall survival [PFS, OS]) with ICI were compared between patients with and without FGFR 2/3, MTAP, ERBB2 alterations. We compared ORR using logistic regression and PFS/OS using Cox proportional hazards. Results: Out of 1,514 patients, 276 (18%), 174 (11%) and 208 (14%) patients had known FGFR2/3, MTAP and ERBB2 alteration status, respectively. and were treated with ICI in 1L or 2 + L. In patients with (vs. without) FGFR2/3 alteration, ORR with ICI was 21% vs. 32% (OR 0.54; [95%CI 0.32-0.91]), PFS was significantly shorter in patients with FGFR2/3 alterations (HR = 1.36 [95%CI 1.03-1.80]; P=0.03); OS was not significantly different (HR = 1.22 [95%CI 0.86-1.47]). In patients with (vs. without) MTAP alteration, ORR with ICI was 25% versus 40% (OR 0.52 [95%CI 0.20-1.38]); PFS and OS were nonsignificantly different. In patients with (vs. without) ERBB2 alteration, ORR with ICI was similar (37% vs. 35%; OR 1.06; 95%CI 0.57-1.97); PFS and OS were significantly longer in patients with ERBB2 alteration [HR 0.63 (95%CI 0.41-0.95); P=0.03; HR 0.66, [95% CI 0.44-0.97]), respectively. Conclusion: Our results support further evaluation of FGFR2/3, MTAP and ERBB2 alterations as putative biomarkers in patients with aUC treated with ICI.