First Successful Treatment of Advanced Intrahepatic Cholangiocarcinoma with Tasurgratinib Following Regulatory Approval: A Case Report from Clinical Practice

Intrahepatic cholangiocarcinoma (iCCA) is a malignancy with limited treatment options in advanced stages. Recently, targeted therapies against fibroblast growth factor receptor 2 (<i>FGFR2</i>) fusions have emerged as a promising approach for selected patients. Tasurgratinib, a selective <i>FGFR1-3</i> inhibitor, was approved in Japan in 2024 for second-line treatment of <i>FGFR2</i> fusion-positive biliary tract cancer. We report the case of a 55-year-old female with advanced iCCA harboring an <i>FGFR2-BICC1</i> 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 <i>FGFR2-BICC1</i> 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.