Candonilimab in Combination With LM-302 for Claudin 18.2 Positive-advanced Biliary Tract Cancer After Failure of Standard of Chemotherapy and PD1/PD-L1 Antibody

Inclusion criteria

• ✓. Advanced BTC that is not resectable or metastatic or recurred after surgery, histologically confirmed, and sufficient tissue specimens are provided for PD-L1, CTLA-4, Claudin18.2 immunohistochemistry and exon sequencing. Claudin18.2 expression is not required at the first stage. In the second stage, Claudin18.2-positive patients were required to be enrolled (≥40% immunohistochemical expression of Claudin18.2 was considered positive, \<40% was considered negative, and two independent pathologists made the judgment. If there was any discrepancy, the third pathologist was asked to make the judgment together).
• ✓. Failure of standard chemotherapy (gemcitabine or platinum or fluorouracil) and PD1/PD-L1 for advanced BTC due to disease progression or toxicity;
• ✓. Measurable lesions;
• ✓. For patients with a prior history of hepatic chemoembolization, radiofrequency ablation/intervention, or radiotherapy, measurable lesions outside the chemoembolization or radiotherapy area or measurable progression lesions at the chemoembolization or radiotherapy site must be present;
• ✓. ECOG physical state ≤ 2;
• ✓. Life expectancy \> 3 months;
• ✓. Adequate renal function: creatinine (Cr) ≤ 1.5 × upper limit of normal (ULN) or glomerular filtration rate (GFR) ≥ 60mL/min/ 1.73m2;
• ✓. Adequate liver function: bilirubin ≤ 1.5 × ULN and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN;