Adebrelimab Combined With AG Regimen in Patients With Unresectable Locally Advanced or Metastatic Pancreatic Cancer

Inclusion Criteria:

* Sign informed consent；
* Aged 18-75 years (inclusive)；
* Histologically or cytologically confirmed pancreatic cancer；
* Unresectable locally advanced or metastatic pancreatic cancer, as determined by the investigator；
* Disease progression after prior treatment with at least one systemic therapy;
* No previous immunotherapy;
* No previous gemcitabine-based chemotherapy;
* Have at least one measurable lesion (according to RECIST 1.1 criteria);
* ECOG 0\~1；
* The estimated survival time is greater than 3 months;
* Adequate Organ Function (within 28 days prior to first dose): Hematology: White blood cell count (WBC) ≥3.0×10⁹/L Absolute neutrophil count (ANC) ≥1.5×10⁹/L Platelets (PLT) ≥100×10⁹/L Hemoglobin (HGB) ≥90 g/L Liver Function: Aspartate aminotransferase (AST) ≤2.5×ULN Alanine aminotransferase (ALT) ≤2.5×ULN Total bilirubin (TBIL) ≤1.5×ULN Renal Function: Serum creatinine (Cr) ≤1.5×ULN or creatinine clearance (CrCl) ≥60 mL/min (calculated via Cockcroft-Gault formula). Coagulation: International normalized ratio (INR) ≤1.5 Activated partial thromboplastin time (APTT) ≤1.5×ULN Cardiac Function: No clinically significant abnormalities on electrocardiogram (ECG)；
* Male subjects and females of childbearing potential must agree to use effective contraceptive measures from the first dose until 3 months after the last dose of the study drug.

Exclusion Criteria:

* The subject has any known active autoimmune disease;
* Subjects have any complications requiring systemic treatment with corticosteroids such as prednisone (\> 10mg/ day) or have used immunosuppressive drugs within 14 days prior to initial administration;
* Subjects received tumor vaccines or other immune-activating antitumor drugs (such as interferon, interleukin, thymosin, or immune cell therapy) within 1 month prior to initial administration;
* Subjects are participating in another clinical trial or have received a drug intervention from another clinical trial within 4 weeks prior to the first dose;
* Subjects have other malignancies requiring treatment;
* Clinically significant cardiovascular disorders；
* Prior allogeneic organ transplantation or hematopoietic stem cell transplantation；
* Serologically confirmed HIV infection；
* Active hepatitis B (HBsAg-positive with HBV-DNA ≥10³ copies/mL). Active hepatitis C (HCV antibody-positive with detectable HCV RNA and requiring antiviral therapy)；
* Known hypersensitivity to monoclonal antibodies or any component of adebrelimab；
* History of severe allergic reactions to gemcitabine or nab-paclitaxel；
* Any situation that the investigator believes may compromise the validity of the trial or patient safety.