Inclusion Criteria:
1. Age: 18 to 75 years old, male or female;
2. Biliary tract malignant tumors confirmed by histology or cytology, with measurable tumor lesions (spiral CT or MR scan ≥10mm, meeting RECIST 1.1 standards);
3. Borderline resectable, locally advanced biliary malignant tumors, including gallbladder cancer, intrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, and distal cholangiocarcinoma;
4. Clinical stage: gallbladder cancer stage: IIIA-IVB; intrahepatic cholangiocarcinoma stage: IIA-IV; hilar cholangiocarcinoma stage: IIIB-IVB; distal cholangiocarcinoma stage: IIIA-IV;
5. Expected survival \> 3 months;
6. ECOG PS score: 0-1 points;
7. Liver function classification is Child-Pugh ≤7;
8. Never received prior systemic treatment for biliary tract tumors;
9. No peritoneal metastasis or other distant metastasis;
10. Normal function of major organs;
11. Women of childbearing age must have a negative pregnancy test (βHCG) before starting treatment, and women of childbearing potential and men (who have sexual active with women of childbearing potential) must agree to effective contraception uninterrupted for the duration of the treatment and for 6 months after the last therapeutic dose;
12. Patients voluntarily enrolled in the study by signing an informed consent form.
Exclusion Criteria:
1. Patients diagnosed with periampullary cancer;
2. Previous or concurrent other malignant tumours within 5 years, except cervical carcinoma in situ, cutaneous squamous cell carcinoma or basal cell carcinoma of the skin that has been basically controlled;
3. Those with uncontrolled, symptomatic brain metastases or a history of uncontrollable mental illness or severe intellectual or cognitive dysfunction;
4. Pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiation pneumonitis, drug-related pneumonia and severely impaired lung function;
5. Suffering from active autoimmune diseases, history of autoimmune diseases, such as interstitial pneumonia, colitis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism; Reduced thyroid function after thyroid hormone replacement therapy can be included;
6. Have a history of immunodeficiency, including testing positive for HIV, suffering from other acquired or congenital immunodeficiency diseases, or a history of organ transplantation and allogeneic bone marrow transplantation;
7. Subjects have cardiovascular clinical symptoms or diseases that cannot be well controlled, including but not limited to: 1) NYHA class II or above heart failure; 2) Unstable angina; 3) Myocardial infarction within 1 year; 4) Clinically significant supraventricular or ventricular arrhythmia requiring clinical intervention;
8. Severe active infection requiring intravenous antibiotic treatment occurs during the screening period;
9. Those who are allergic to experimental drugs;
10. Patients who cannot comply with the trial protocol or cannot cooperate with follow-up visits;
11. Those who the researcher believes are not suitable to participate in this trial.
