An Open-label, Single-arm, Multicenter Exploratory Study of Adebrelimab Combined With Gemcitabine and Albumin-bound Paclitaxel as First-line Treatment for Biliary Tract Malignancies

Inclusion Criteria: * Age 18 to 75 years, male or female. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1. No prior local or systemic treatment for biliary tract malignancy. Histologically or cytologically confirmed initially unresectable or inoperable biliary tract cancer; recurrent biliary tract tumor after surgery; or patients who received post-operative adjuvant therapy must have been off treatment for more than 6 months. Adequate organ and hematological function. Life expectancy of ≥ 3 months. Laboratory results within 7 days prior to the first dose meeting the following criteria:Absolute neutrophil count (ANC) ≥ 1.5 × 10\^9/L, Platelets ≥ 75 × 10\^9/L, Hemoglobin ≥ 90 g/L (without blood transfusion or G-CSF within 2 weeks prior to screening); Serum albumin ≥ 30 g/L, Total bilirubin ≤ 1.5 × ULN, ALT and AST ≤ 3 × ULN, Serum creatinine ≤ 1.5 × ULN or Creatinine clearance \> 50 mL/min; INR ≤ 1.2 or PT exceeding the normal control range by ≤ 2 seconds; Urine protein \< 2+ (if ≥ 2+, 24-hour urine protein quantification must be \< 1.0 g). Women of childbearing potential must agree to abstain from sexual intercourse or use a reliable and effective method of contraception from the time of signing the informed consent form until at least 120 days after the last dose of the study drug. Women of childbearing potential must have a negative serum pregnancy test within 72 hours prior to the first dose and must not be lactating. Male subjects with female …