A Study of MR001 Combined With Chemotherapy in Patients With Locally Advanced or Metastatic Pancreatic Ductal Adenocarcinoma (PDAC) After First-line Therapy

Inclusion Criteria: * Histologically or cytologically confirmed locally advanced or metastatic PDAC, progressed after only one prior line of systemic therapy. * At least one measurable lesion per RECIST v1.1. * ECOG Performance Status of 0-1. * Life expectancy \>3 months. * Adequate organ and marrow function as defined by laboratory parameters. * Voluntarily sign the informed consent form. Exclusion Criteria: * Known hypersensitivity to MR001 or similar monoclonal antibodies. * Requirement for systemic immunosuppressive therapy within 14 days before first dosing. * Uncontrolled active infections or concurrent malignancies. * Not adequately controlled active brain metastases or leptomeningeal metastasis. * Clinically significant cardiovascular, renal, or hepatic disorders. * Pregnant or breastfeeding women. * Any other circumstances which the investigator considers may increase risks to subjects or interfere with the results of the trial.