Are there instances where you would offer erdafitinib instead of avelumab for maintenance therapy for FGFR3 mutated metastatic bladder cancer after stable disease on cisplatin/gemcitabine?  

Is there concern for increased toxicity from erdafitinib following avelumab similar to osimertinib toxicity following pembrolizumab in NSCLC? Does FGFR3 mutation predict for lack of immunotherapy response?

Answer from: Medical Oncologist at Community Practice