Abstract
Intrahepatic cholangiocarcinoma (iCCA) is a malignancy with limited treatment options in advanced stages. Recently, targeted therapies against fibroblast growth factor receptor 2 (FGFR2) fusions have emerged as a promising approach for selected patients. Tasurgratinib, a selective FGFR1-3 inhibitor, was approved in Japan in 2024 for second-line treatment of FGFR2 fusion-positive biliary tract cancer. We report the case of a 55-year-old female with advanced iCCA harboring an FGFR2-BICC1 fusion, who experienced a rapid clinical response to tasurgratinib following disease progression on gemcitabine, cisplatin, and durvalumab (GCD). Following the failure of GCD therapy, treatment with oral tasurgratinib was initiated at 140 mg/day and subsequently reduced to 105 mg/day due to Grade 2 diarrhea. Within weeks, imaging and tumor markers indicated a partial response, accompanied by a reduction in ascites, and improved performance status. The response sustained for several months without evidence of disease progression. Notably, no substantial clinical hyperphosphatemia or anorexia was observed during treatment. This is the first report to describe the real-world clinical efficacy of tasurgratinib in an iCCA patient with FGFR2-BICC1 fusion. Our findings suggest that tasurgratinib can provide a rapid and durable response with manageable toxicity in molecularly selected patients who have progressed on standard therapies.