Radiotherapy With Sequential Chemotherapy Combined With PD-1 Inhibitor and Thymalfasin for BRPC

Inclusion Criteria:

1. Age ≥ 18 years, with ECOG score of 0 \~ 1;
2. Histologically or cytologically confirmed diagnosis of ductal adenocarcinoma of pancreas;
3. Classification as borderline resectable pancreatic cancer according to the NCCN Guidelines (2024 Edition);
4. Deemed suitable for neoadjuvant therapy following discussion by the MDT team of the study site;
5. Subjects must meet the following criteria for hematology test:

   1. Neutrophil count ≥ 1.5 × 10\^9/L
   2. Hemoglobin ≥ 10 g/dL
   3. Platelet count ≥ 100 × 10\^9/L
6. Subjects must meet the following criteria for blood chemistry tests:

   1. Total bilirubin ≤ 1.5 × upper limit of normal (ULN)
   2. AST and ALT \< 1.5 × ULN
   3. Creatinine clearance ≥ 60 mL/min
   4. Good coagulation, defined as international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5 × ULN
7. Subjects of childbearing potential should take appropriate protective measures (contraceptive methods or other birth control methods) prior to enrollment and throughout the clinical study;
8. Has signed the informed consent form;
9. Capable of complying with the study protocol and follow-up procedures.

Exclusion Criteria:

1. Prior systemic anti-tumor therapy;
2. Prior medical history of other tumors, except for cervical carcinoma in situ, treated squamous cell carcinoma or urothelial bladder carcinoma (Ta and TIS), or other malignant tumors that have received radical treatment (at least 5 years prior to enrollment);
3. Prior history of abdominal radiotherapy;
4. Subjects with active bacterial or fungal infection (≥ Grade 2 as per NCI-CTC, Version 3).
5. Subjects with HIV, HCV, or HBV infection, uncontrollable coronary artery disease or asthma, uncontrollable cerebrovascular disease or other diseases judged by the investigator to be ineligible for enrollment;
6. Subjects with autoimmune diseases or immunodeficiency and requiring treatment with immunosuppressive agents;
7. Pregnant or lactating women; women of childbearing potential must have a negative pregnancy test results within 7 days prior to enrollment;
8. Subjects with drug abuse/clinical/psychological/social factors that affect informed consent or study conduct;
9. Subjects who may be allergic to PD-1 monoclonal antibody immunotherapy drugs;
10. Patients who are scheduled to undergo or have previously undergone organ or bone marrow transplant;
11. Patients requiring treatment with systemic corticosteroids (at dose level \> 10 mg/day prednisone efficacy) or other immunosuppressive drugs within 14 days prior to the first dose or during the study. However, enrollment is permitted if: In the absence of active autoimmune disease, patients are permitted to use topical or inhaled steroids, or adrenal hormone replacement therapy at dose level ≤ 10 mg/day prednisone efficacy;
12. Treatment with live vaccines within 28 days prior to the first dose; except for inactivated viral vaccines for seasonal influenza;
13. Active pulmonary tuberculosis;
14. Treatment with related drugs or medical technology affecting immunity within 6 months prior to the first dose (including but not limited to: thymopentin, thymalfasin, interferon, CAR-T therapy, etc.);
15. Patients with other conditions unsuitable for this clinical trial judged by the investigator.