This Phase II clinical study evaluates the safety and efficacy of a combination therapy for patients with pancreatic cancer that has spread to the liver. Because liver metastases are a major factor in the progression of pancreatic cancer, this research utilizes Hepatic Arterial Infusion Chemotherapy (HAIC) to deliver high-concentration treatment directly into the tumor's blood supply. The multi-step strategy involves first infusing Sodium Bicarbonate to neutralize the acidic tumor microenvironment , followed by the NASOX chemotherapy regimen (Oxaliplatin and Liposomal Irinotecan) and an intra-arterial PD-1 inhibitor to boost immune response. Patients also receive oral S-1 to maintain treatment effect. The primary goal is to determine if this integrated approach can improve Overall Survival for patients compared to historical standard treatments.

Inclusion Criteria:

• Aged 18 years and above, with no gender restrictions;

• Pathologically confirmed pancreatic cancer (originating from the pancreatic ductal epithelium), with metastasis to the liver;

• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2;

• Adequate organ function, meeting the following criteria:

  a. Hematological tests:

  1. Neutrophils ≥ 1.5 × 10⁹ /L;
  2. White blood cells ≥ 3.0 × 10⁹ /L;
  3. Platelets ≥ 85 × 10⁹ /L;
  4. Hemoglobin ≥ 70 g/L; b. Biochemical tests:
  1. Total bilirubin ≤ 2× upper limit of normal (ULN) (for subjects with biliary obstruction, after biliary drainage ≤ 2.5 × ULN);
  2. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in metastatic subjects ≤ 5 × ULN;
  3. Albumin level ≥ 28 g/L;
  4. Creatinine clearance rate ≥ 60 ml/min; c. Cardiac function tests:
  1. Normal electrocardiogram (ECG) or ECG abnormalities deemed clinically insignificant by the investigator;
  2. Left ventricular ejection fraction (LVEF) ≥ lower limit of normal;

• At least 3 weeks post-surgery, radiotherapy, chemotherapy, or other anti-tumor treatments, with general physical condition or related adverse reactions having recovered (toxicity ≤ grade 1) or stabilized;

• Willing to participate and sign the informed consent form;

• Good compliance and agreement to cooperate with survival follow-up.

Exclusion Criteria:

• Subjects with ascites requiring clinical intervention (including moderate to large amounts of ascites; subjects with ascites need to be stable for more than 4 weeks after drainage);
• Clinically severe gastrointestinal diseases (including bleeding, infectious inflammation, perforation, obstruction, or diarrhea greater than grade 1);
• NRS pain score ≥ 4 after standardized treatment with analgesics;
• Second primary malignancy within 5 years (except cured carcinoma in situ, basal cell, or squamous cell skin cancer; subjects with other previous tumors can be enrolled if there has been no recurrence within 5 years);
• Uncontrolled cardiovascular or cerebrovascular diseases with clinical symptoms, including but not limited to: ① NYHA class III or higher heart failure; ② unstable angina; ③ myocardial infarction or stroke within 6 months; ④ supraventricular or ventricular arrhythmias requiring treatment or intervention; ⑤ uncontrolled hypertension (systolic blood pressure > 150 mmHg and/or diastolic blood pressure > 90 mmHg despite optimal treatment);
• Known active hepatitis B subjects (HBsAg positive and HBV DNA ≥ 10³ copies or ≥ 1000 U/ml);
• Active infection or unexplained fever > 38.5°C during the screening period or on the day of administration (subjects with fever caused by tumors can be enrolled as judged by the investigator), which, in the investigator's judgment, would affect the subject's participation in this trial or interfere with the evaluation of efficacy;
• Pregnant or breastfeeding women;
• Women of childbearing potential with a positive blood (urine) pregnancy test during the screening period (both male and female subjects should use reliable contraception during the trial and for 3 months after the last dose to prevent pregnancy);
• Subjects with other medical or social issues that, in the investigator's judgment, might affect their ability to sign informed consent, participation in the trial, or interpretation of the trial results;
• Patients with an estimated survival time of ≤ 3 months are not included in this study.