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.
