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.

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.

Conclusions: Our results support further evaluation of FGFR2/3, MTAP and ERBB2 alterations as putative biomarkers in patients with aUC treated with ICI.