Favorable Management of Repeated Serous Retinal Detachment with Continued Tumor Response in a Patient with Intrahepatic Cholangiocarcinoma during Treatment with Pemigatinib.

Pemigatinib is a fibroblast growth factor receptor inhibitor (FGFRi) approved for the treatment of patients with previously treated biliary tract cancer with FGFR2 fusion. Although infrequent, ocular toxicity manifested as serous retinal detachment (SRD) has been observed and is regarded as a serious side effect. We herein report the case of a 54-year-old woman with unresectable cholangiocarcinoma-initiated pemigatinib after failure of gemcitabine plus S-1 (GS). Although the patient experienced repeated SRD after pemigatinib, dose interruption and dose reduction of pemigatinib from 13.5 mg to 9 mg, and from 9 mg to 4.5 mg led to complete recovery of SRD, and continued tumor shrinkage.