The investigators plan to initiate a prospective, multicenter, phase II study, recruiting 80 patients with advanced pancreatic cancer who have not received prior treatment. This study aims to enhance the anti-tumor immune effect through the combination of QL1706+Lenvatinib+AG regimen, thereby improving the prognosis of patients with advanced metastatic pancreatic cancer.

Inclusion Criteria:

• a. Age ≥18 years, ECOG performance status ≤2, and expected survival of ≥3 months.
• b. Patients with histologically or cytologically confirmed advanced metastatic pancreatic cancer.
• c. At least one measurable lesion according to RECIST 1.1 criteria;
• d. No prior anti-tumor treatment of any kind.
• e. Patients must meet the following hematological criteria: e1. White blood cell count (WBC) ≥3.0×10^9/L; e2. Absolute neutrophil count (ANC) ≥1.5×10^9/L; e3. Hemoglobin (HB) ≥90 g/L; e4. Platelet count (PLT) ≥75×10^9/L; e5. Total bilirubin (TBIL) ≤1.5× upper limit of normal (ULN); e6. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5×ULN; if there is liver metastasis, then ALT and AST ≤5×ULN; e7. Serum creatinine (Cr) ≤1×ULN or creatinine clearance (CCr) ≥50 ml/min;
• f. Doppler ultrasound assessment: Left ventricular ejection fraction (LVEF) ≥ lower limit of normal (50%).
• g. Patients of childbearing potential must take appropriate protective measures (contraception or other methods of fertility control) before enrollment and during the study.
• h. Willingness to participate in the study, with signed informed consent, good compliance, and cooperation with follow-up; able to adhere to the study protocol and follow-up procedures.

Exclusion Criteria:

• a. Prior receipt of systemic anti-tumor treatment, such as chemotherapy, radiotherapy, or other anti-tumor treatments.
• b. Participation in another drug clinical trial within the past 4 weeks.
• c. Subjects who, in the investigator's judgment, have the opportunity for surgery or are potentially operable (subjects who voluntarily forgo surgical treatment may be enrolled after investigator assessment and agreement).
• d. Subjects with moderate ascites requiring drainage (except for those with minimal ascites shown on imaging without symptoms).
• e. Known symptomatic central nervous system metastases and/or carcinomatous meningitis.
• f. History of other primary malignancies, except for the following: 1) Malignancies that have been in complete remission for at least 2 years prior to enrollment and do not require other treatments during the study; 2) Non-melanoma skin cancer or malignant lentigo that has been adequately treated and shows no evidence of disease recurrence; 3) Carcinoma in situ that has been adequately treated and shows no evidence of disease recurrence.
• g. Patients with autoimmune diseases or immune deficiencies who are being treated with immunosuppressive drugs.
• h. Patients with a tendency to bleed.
• i. Pregnant or breastfeeding women. Women of childbearing potential must have a negative pregnancy test within 7 days prior to enrollment.
• j. Drug abuse, or clinical, psychological, or social factors that may affect informed consent or study implementation.
• k. Subjects who may be allergic to epaltrastide (QL1706), lenvatinib, albumin-bound paclitaxel, or gemcitabine.