An Exploratory Study on the Use of Ivosidenib for the Precise Treatment of Advanced Biliary Tract Malignancies With IDH1 Mutations in the Later Line of Therapy.

Inclusion Criteria

* Voluntary Participation: Signed informed consent.
* Genetic Mutation: Presence of an IDH1 mutation confirmed by genetic testing.
* Disease Status：
* Newly diagnosed, untreated advanced/metastatic disease; OR
* Recurrence \>6 months after curative-intent surgery (with or without adjuvant therapy).
* Measurable Disease: At least one measurable lesion per RECIST 1.1.
* Performance Status: ECOG performance status of 0 or 1.
* Life Expectancy： ≥3 months.
* Organ Function: Adequate hematological, hepatic, and renal function.
* Contraception: Use of highly effective contraception for women of childbearing potential and men.

Exclusion Criteria

* Prior Treatment: Previous treatment with Ivosidenib.
* Cancer Type: Ampulla of Vater cancer.
* Pregnancy： Pregnant or breastfeeding women.
* Allergy: Known hypersensitivity to any component of the study drugs.
* Recent Therapy: Local anti-tumor therapy or major surgery within 4 weeks prior to initiation.
* Medical Conditions:
* Uncontrolled hypertension.
* Significant cardiovascular disease.
* Active or untreated CNS metastases.
* Active autoimmune disease.
* Uncontrolled active infection (e.g., HBV, HCV, HIV).
* Significant bleeding tendency or history.
* Severe non-healing wounds.
* History of organ transplantation.
* Concurrent Participation: Participation in another interventional clinical trial.