Klin Onkol 2025; 38(2): 148-152. DOI: 10.48095/ccko2025148.
Background: Cholangiocarcinoma is an aggressive cancer with an increasing incidence and a poor prognosis, typically resulting in a median survival of about 12 months for advanced cases. The standard treatment has been platinum-based systemic chemotherapy, although its effectiveness is often limited. Genetic alterations, such as mutations in the IDH1 gene, offer potential targets for targeted therapies, particularly in patients with intrahepatic cholangiocarcinoma. Ivosidenib, an oral IDH1 inhibitor, has shown improved progression-free survival in patients with IDH1-mutated cholangiocarcinoma, according to phase III ClarIDHy study. Observation: We present the case of a 62-year-old patient diagnosed with advanced cholangiocarcinoma and an IDH1 mutation. The patient initially responded to standard chemotherapy, which led to a temporary stabilisation of the disease; however, progression was noted after 6 months. Given the presence of the IDH1 alteration, the patient was treated with ivosidenib as a second-line therapy. This treatment resulted in disease stabilisation according to RECIST criteria. Subjectively, the patient experienced a significant improvement in the quality of life. The patient achieved more than three times longer progression-free survival than was achieved in the clinical trial, without the need for dose reduction. Conclusion: This case highlights the importance of targeted therapy for patients with IDH1-mutated cholangiocarcinoma. Not only was objective disease stabilisation achieved, but there was also a significant subjective improvement in the quality of life. This underscores the value of molecular testing and supports the use of personalised medicine when treating rare cancer types like cholangiocarcinoma, even in instances where objective responses are relatively uncommon.