• The patient had good compliance, could understand the research process of the study, and signed a written informed consent;

• Age ≥18 years, ≤75 years;

• Histologically or cytologically confirmed cholangiocarcinoma;

• Documented metastatic disease;

• At least one measurable lesion according to RECIST v1.1;

• Disease progression after gemcitabine + immunotherapy;

• For patients whose disease recurred after curative resection (R0 or R1), previous adjuvant 5-FU-based chemotherapy is allowed if there is at least 6 month-interval between the last dose of adjuvant chemotherapy and recurrence of disease;

• Eastern Cooperative Oncology Group (ECOG) Performance status 0-1;

• The expected survival time is greater than 3 months;

⁃ Having adequate organ function, as defined below:

∙ Absolute neutrophil count (ANC) ≥1.5\*109/L

‣ Hemoglobin ≥90g/dL

‣ Platelets (PLT) ≥100\*109/L

‣ Total bilirubin \< 1.5 times Upper Normal Value (ULN)

‣ Chemical examination of liver function index (AST\&ALT) \< 2.5 times Upper Limit of Normal (ULN)

‣ Serum creatinine (Cr) ≤1.5×ULN

⁃ Non-pregnant or lactating women; Effective contraception should be used by women/men of childbearing age during the study period and for 6 months after the end of study treatment-