To evaluate the efficacy of PD-L1/CTLA4 BsAb for the second line treatment and the combination with chemotherapy for the first line treatment in pancreatic cancer

Subjects who signed the informed consent were assigned to three cohorts according to the actual treatment status. Cohort 1 enrolled subjects receiving PD-L1/CTLA4 BsAb 5mg/kg iv Q2W for 2nd treatment; cohort 2 enrolled subjects receiving PD-L1/CTLA4 BsAb in combination with gemcitabine/albumin- paclitaxel as 1st treatment for 4-6 cycles with PD-L1/CTLA4 BsAb monotherapy maintainence; cohort 3 enrolled subjects received systemic chemotherapy, receiving PD-L1/CTLA4 BsAb combined with oxaliplatin / irinotecan / leucovorin / fluorouracil (FOLFIRINOX) as 1st treatment for 4-6 cycles withPD-L1/CTLA4 BsAb monotherapy maintainence; until disease progression according to RECIST 1.1, intolerable toxicity, withdrawal, death, 2-yr treatment,who comes first.

Inclusion Criteria:

• Histology or cytology confirmed as pancreatic ductal adenocarcinoma;
• ECOG 0-1;
• adequate organ function (absolute neutrophil count ≥1.5 x 109/L; platelet count ≥100 x 109/L; creatinine < 1.5 x ULN (upper normal) or calculated creatinine clearance ( CRCI) ≥ 60mL/min; albumin ≥ 30g/L; total bilirubin <1.5 x ULN; aspartate aminotransferase (AST) < 2.5 x ULN; alanine aminotransferase (ALT) < 2.5x ULN; INR or PT < 1.5x ULN, and aPTT <1.5x ULN);
• no obvious symptoms of jaundice and ascites;
• no other serious underlying diseases

Exclusion Criteria:

• patients with active brain metastases;
• history of autoimmune diseases, or need to be treated with corticosteroids and immunosuppressive agents;
• past history of unstable angina, symptomatic congestive heart failure, severe arrhythmia, myocardial infarction within 6 months, QT interval prolongation (>450ms);
• other malignant tumors within the last 5 years;
• pregnant or lactating women;
• NRS ≥ 4 points;
• unintentional weight loss ≥ 5% within 1 month before the first dose even if peripheral or central vein nutrition support,