Table 1 The key eligible criteria of this trial

Age between 18 and 80 years

Synchronous or metachronous (within 5 years) malignancies

Unresectable locally advanced or metastatic pancreatic cancer that is pathologically diagnosed as adenocarcinoma

Females who are pregnant, or lactating

No prior anti-tumor treatment for pancreatic cancer

New known or suspected uncontrolled metastases to brain

ECOG PS: 0 to 2

Serious or uncontrolled infectious disease (HIV、active tuberculosis、HBV DNA>103/ml)

Life expectancy ≥3 months

Active autoimmune disease requiring systemic treatment in the past 2 years

No history of autoimmune diseases

Immunodeficiency, or receipt of systemic steroid therapy or immunosuppressive therapy within 7 days of the first dose of the study drug

Adequent organ function as below:

Tumor infiltration to any important blood vessels and nerves

Absolute neutrophil count ≥1500/mm³

Concurrent other kinds of chemotherapy, targeted therapy, hormone therapy, immunotherapy, radiotherapy (except local symptomatic radiotherapy) or traditional Chinese medicine during the trial course

Platelet count ≥80,000/mm3

History of chemotherapy or immune checkpoint inhibitors

Haemoglobin ≥9.0 g/dL

Patients with serious complications, such as:

Total bilirubin ≤2 × ULN

Uncontrollable cardiovascular disease, angina and arrhythmia

Aspartate aminotransferase ≤3 × ULN (≤ 5 × ULN in patients with liver metastases)

History of myocardial infarction

Alanine aminotransferase ≤3 × ULN (≤ 5 × ULN in patients with liver metastases)

History of hemorrage or thromboembolic events within the last 6 months

Child-Pugh score ≤ 7

Uncontrollable diabetes mellitus or hypertension

Uric acid< 500 μmol/L

Uncontrolled intestinal lung disease or pulmonary fibrosis

Serum creatinine ≤1.7 mg/dL

Other patients who are considered to be unsuitable for this study by the investigator

Creatinine clearance ≥60 mL/min

Proteinuria ≤2 g/24 h

QTc interval ≤ 480 ms in ECG

Written informed consent