Fibroblast Growth Factor Receptor 3 is a transmembrane tyrosine kinase receptor that regulates cell proliferation, differentiation, and survival. In urothelial carcinoma, activating mutations, fusions, or overexpression of FGFR3 are common oncogenic drivers that promote tumor progression. Vofatamab blocks FGFR3 by preventing ligand binding and receptor dimerization, thereby inhibiting downstream MAPK and PI3K/AKT signaling pathways.