• Age ≥18, male or female;

• Patients with histologically or cytologically confirmed unresectable or metastatic BTC, including intrahepatic cholangiocarcinoma (IHCC), extrahepatic cholangiocarcinoma (EHCC), and gallbladder cancer (GBC); Surgical resection with positive margins are allowed;

• ECOG score 0-2;

• Expected survival of ≥12 weeks;

• Confirmed measurable (or evaluable) lesions that meet the requirements of RECIST 1.1;

• It is not less than 7 days since the end of the last systematic treatment, and the palliative treatment of the limited area is allowed

• Treatment has been over 4 weeks;

• The function of major organs and bone marrow was basically normal;

• Fully understand this study, voluntarily participate in it, and sign the informed consent.

• Fertile male or female patients shall volunteer to use effective contraceptive methods, such as double barrier contraception, condoms, oral or injected contraceptives, and intrauterine devices, during the study period and within 90 days after the last dosing of the investigational drug. All-female patients will be considered fertile unless they have had natural menopause, or artificial menopause, or sterilization (such as hysterectomy, bilateral adnexectomy, or ovarian radiation)