Erdafitinib for the Treatment of Patients With Castration-Resistant Prostate Cancer

Inclusion Criteria: * Age \>= 18 years * Histologically proven adenocarcinoma or small cell of the prostate with evidence for skeletal metastases on bone scan and/or computed tomography (CT)/positron emission tomography (PET)/magnetic resonance imaging (MRI) scan. Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Serum testosterone levels =\< 50 ng/ml and maintenance of castration with luteinizing hormone-releasing hormone (LHRH) agonist/antagonist or orchiectomy * Patients must have documented evidence of progressive disease as defined by any of the following: * PSA progression: minimum of 2 rising values (3 measurements) obtained a minimum of 7 days apart with the last result being at least \>= 1.0 ng/mL * New or increasing non-bone disease (Response Evaluation Criteria in Solid Tumors \[RECIST\] 1.1 criteria) * Positive bone scan with 2 or more new lesions (Prostate Cancer Working Group 3 \[PCWG3\]) * Prior treatment with a second-generation AR-targeting agent (e.g. abiraterone acetate, enzalutamide, apalutamide) is required. Patients may have received up to two such agents * Patients may have received prior treatment with immunotherapies (sipuleucel-T, checkpoint immunotherapies) or bone targeting therapies (radium-223) * Both chemotherapy-naive and patients previously treated with chemotherapy are eligible. Chemotherapy pretreated patients may have received a maximum of two prior systemic cytotoxic chemotherapies completed at least 3 weeks prio…