To evaluate the safety and efficacy of neoadjuvant HRS-4642 plus chemotherapy with or without adebrelimab in patients with pancreatic ductal adenocarcinoma.

Inclusion Criteria:

1. Male and female participants aged 18-70 (including those who are 18 and 70 years old)；
2. Pathologically or cytologically confirmed ductal adenocarcinoma of the pancreas; and subjects must have at least one measurable lesion as defined by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1);
3. Life expectancy ≥ 12 weeks;
4. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1;
5. Adequate marrow and organ function;

Exclusion Criteria:

1. Prior receipt of any anti-tumor therapy, including but not limited to systemic chemotherapy, radiotherapy, interventional therapy, immunotherapy, targeted therapy, and anti-tumor traditional Chinese medicine therapy;
2. Presence of distant metastatic lesions confirmed by imaging;
3. Known hypersensitivity to the investigational drug or any of its excipients;
4. Presence of any serious or uncontrolled systemic disease;
5. History of allogeneic hematopoietic stem cell transplantation or solid organ transplantation;
6. Clinically significant acute or chronic pancreatitis;
7. Participation in any interventional clinical trial involving drugs or medical devices within 4 weeks prior to the first administration of study treatment;
8. Vaccination with live or live-attenuated vaccines within 4 weeks prior to the first dose of the investigational drug;
9. Any other condition that, in the judgment of the investigator, makes the subject unsuitable for enrollment.