Management of Fibroblast Growth Factor Inhibitor Treatment–emergent Adverse Events of Interest in Patients with Locally Advanced or Metastatic Urothelial Carcinoma

Background: Erdafitinib is indicated for the treatment of adults with locally advanced/metastatic urothelial carcinoma and susceptible FGFR3/2 alterations progressing on/after one or more lines of prior platinum-based chemotherapy. Objective: To better understand the frequency and management of select treatment-emergent adverse events (TEAEs) to enable optimal fibroblast growth factor receptor inhibitor (FGFRi) treatment. Design, setting, and participants: Longer-term efficacy and safety results of the BLC2001 (NCT02365597) trial in patients with locally advanced and unresectable or metastatic urothelial carcinoma were studied. Intervention: Erdafitinib schedule of 8 mg/d continuous in 28-d cycles, with uptitration to 9 mg/d if serum phosphate level was