This is an investigator-initiated, open-label, single-arm, phase II trial evaluating the efficacy and safety of serplulimab (an anti-PD-1 monoclonal antibody) plus bevacizumab, combined with either FOLFIRINOX or NALIRIFOX chemotherapy, as second-line treatment for metastatic pancreatic ductal adenocarcinoma. The study will enrol up to 34 patients.
Voluntary participation with signed written informed consent, good compliance, and willingness to adhere to follow-up visits.
Age ≥ 18 years, male or female.
Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1 and life expectancy ≥ 3 months.
Histologically or cytologically confirmed locally advanced unresectable or metastatic pancreatic adenocarcinoma.
Prior treatment with anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CTLA-4 antibodies, or any other agents specifically targeting T-cell co-stimulation or immune checkpoint pathways.
Prior treatment with bevacizumab or other anti-angiogenic agents. Radiological evidence of major vascular tumor invasion or high risk of fatal hemorrhage; active gastrointestinal bleeding, persistent bleeding disorders, or coagulopathy.
Radiotherapy (except for palliative reasons), endocrine therapy, chemotherapy, immunotherapy, or molecular targeted therapy within 4 weeks prior to the first dose (bisphosphonates for bone metastases are allowed).
Uncontrolled central nervous system (CNS) metastases (i.e., symptomatic or requiring corticosteroids or mannitol for symptom control).