Comparative safety of futibatinib vs pemigatinib in metastatic cholangiocarcinoma: FAERS-based analysis.

512 Background: Fibroblast Growth Factor Receptor (FGFR) inhibitors have transformed treatment for patients with metastatic cholangiocarcinoma with FGFR2 fusion or other rearrangement. Pemigatinib and Futibatinib have shown measurable clinical benefit after progression on first line systemic therapy and are known to cause ocular toxicities and hyperphosphatemia. But comparative post-marketing safety data is limited. Using FDA Adverse Event Reporting System (FAERS) pharmacovigilance data, we evaluated real-world adverse events (AEs) associated with these agents. Methods: We queried FAERS between 2014–2025 using AERSMine to identify AEs in patients with metastatic cholangiocarcinoma treated with FGFR inhibitors. Cohorts were mutually exclusive: futibatinib (N=90) and pemigatinib (N=469). AEs were categorized as metabolic, dermatologic and ocular. Chi-Square and Fisher’s Exact tests assessed statistical significance. Results: Overall, AE distribution differed significantly (χ²=24.3, df=6, p