Surufatinib Combined With KN046 and AG Regimen Chemotherapy as First-Line Treatment for Unresectable Advanced Pancreatic Cancer

Inclusion Criteria: * Signed informed content obtained prior to treatment. * Male or female, age ≥ 18 years and ≤ 75 years. * Patients must have histologically or cytologically confirmed pancreatic adenocarcinoma that originated from the pancreatic ductal epithelial, with image-documented unresectable locally advanced or distant metastatic disease. * Patients have received no previous local treatment such as surgery, radiotherapy, ablation, or any systemic treatment for advanced/metastatic pancreatic cancer, including neoadjuvant and/or adjuvant therapy. * Have at least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Expected overall survival of ≥ 6 months. * Laboratory test results within 7 days prior to first dose of study drugs must meet the following criteria: 1. absolute neutrophil count (ANC) ≥ 1.5 × 109/L, platelet count (PLT) ≥ 100 × 109/L and hemoglobin (HGB) ≥ 90 g/L. 2. total bilirubin (TBil) ≤ 1.5 × the upper limit of normal (ULN). 3. alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 1.5 × ULN in the absence of liver metastases; ALT and AST ≤ 3 × ULN in the presence of liver metastases. 4. serum creatinine (SCr) ≤ 1.5 × ULN and creatinine clearance (CCl) ≥ 50 mL/min (calculated according to the Cockcroft-Gault formula). 5. urine protein \<2+ in urine analysis; if urine protein ≥2+, 24-hour urine protein quantification should be \<1g. 6. international normalized ratio (INR) ≤ 1.5 and partial activation prothrombin time (APTT) ≤ 1.5 × ULN. * Female subjects of childbearing age or male subjects whose partner is a female of childbearing age should use effective contraception from at least 1 month prior to the first dose of study drugs to 6 months after the last dose of study drugs. Exclusion Criteria: * Adverse events (AEs) due to previous anti-tumor therapy have not recovered to CTCAE Grade ≤1 (except for hair loss, skin pigment changes, or Grade ≤ 2 neurotoxicity). * Other malignancies diagnosed within past 5 years (except basal cell carcinoma of the skin or squamous cell carcinoma and carcinoma in situ of the cervix that have been effectively controlled). * Presence of central nervous system (CNS) metastases at screening, or have a history of CNS metastases. * Patients who have received approved systemic anti-tumor therapy within 4 weeks before the first dose of study drugs, including chemotherapy, biological therapy, targeted therapy, hormone therapy, traditional Chinese medicine therapy (with clear anti-tumor indications in the label), etc. * Patients who have received radical radiotherapy (including radiotherapy involving \> 25% bone marrow) within 4 weeks prior to the first study drugs reception; Or brachytherapy (e.g., implanted radioparticles) within 60 days prior to the first dose of the study drugs; Or palliative radiotherapy for bone metastases within 1 week prior to first dose of the study drugs. * Patients who have undergone major surgery within 4 weeks before receiving first dose of study drugs, or have unhealed wounds, ulcers or fractures. * Vaccination within 4 weeks before the first dose of study drugs or plan to have during the study period, except for inactivated vaccines. * Patients who have previously received anti-VEGF/VEGFR agents and have experienced disease progression during treatment or within 3 months after the last dose. * Patients with uncontrollable malignant pleural effusion, ascites, or pericardial effusion (no response to diuretics or puncture as per the investigator's judgement). * Presence of gastrointestinal diseases such as active gastric and duodenal ulcers, ulcerative colitis, or active bleeding in unresected tumors, or other conditions that may cause gastrointestinal bleeding or perforation as determined by the investigator. * Patients with evidence or history of thrombosis or significant bleeding tendency (bleeding \>30 mL within 2 months, hematemesis, melena, hematochezia, or hemoptysis \>5mL within 4 weeks) within 2 months prior to the first dose of the study drugs. * Patients who have arterial thrombosis or deep vein thrombosis within 6 months, or have thromboembolic events (including stroke and/or transient ischaemic attack) within 12 months prior to first dose of the study drugs. * Patients who are receiving anti-tuberculosis therapy for active pulmonary tuberculosis, or have had anti-tuberculosis therapy within 1 year prior to first dose of the study drugs. * Patients with a previous or current history of pulmonary disorder that may interfere the identification and management of suspected drug-related pulmonary toxicity, including pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiation pneumonia, drug-related pneumonia, severe impairment of lung function, etc. (radiation pneumonia in radiotherapy areas is allowed). * Presence of corneal lesions, including but not limited to bullous keratopathy, shingle corneal degeneration, corneal abrasions, corneal ulcers, keratitis, etc. * History of clinically significant hepatic disease, including, but not limited to, known hepatitis B virus (HBV) infection with HBV DNA positive; known Hepatitis C virus (HCV) infection with HCV RNA positive; or other hepatitis, liver cirrhosis, etc. * Positive for human immunodeficiency virus (HIV) antibodies. * Meet any of the following criteria for cardiac function: 1. Clinically significant arrhythmias or conduction abnormalities requiring clinical intervention. 2. Electrocardiogram (ECG) indicating an QT interval (QTcF) of \> 480 msec. 3. Clinically significant cardiovascular diseases, including acute myocardial infarction within 6 months prior to enrollment, severe/unstable angina pectoris, coronary artery bypass grafting, congestive heart failure according to the New York Heart Association (NYHA) classification III/IV, ventricular arrhythmias needing drug intervention, LVEF \<50%. * Previous or current autoimmune diseases, including but not limited to Crohn's disease, ulcerative colitis, systemic lupus erythematosus, sarcoidosis, Wegener syndrome, Graves' disease, rheumatoid arthritis, pituitary inflammation, ocular pigmentitis, autoimmune hepatitis, systemic sclerosis, Hashimoto's thyroiditis, autoimmune vasculitis, autoimmune neuropathy (Guillain-Barre syndrome), with exceptions as follows: type I diabetes, hormone replacement therapy-stabilized hypothyroidism, psoriasis or vitiligo that does not require systemic therapy. * Women who are pregnant or lactating. * Known history of allergy to the relevant ingredients of the study drugs. * Subjects who have received investigational treatments in other clinical studies within 4 weeks prior to first dose of study drugs. * Patients who have any disorder or condition that may affect absorption of the study drugs, or who are unable to take oral medication. * Patients unsuitable for participating due to other reasons as per investigator's determination.