A Study Comparing MRG004A Plus Best Supportive Care Versus Placebo and Best Supportive Care in the Treatment of Patients With Advanced Pancreatic Cancer

Inclusion Criteria: * Willing to sign the informed consent form and follow the requirements specified in the protocol. * Patients with histologically and cytologically confirmed locally advanced or metastatic pancreatic cancer, including adenocarcinoma, who have failed at least prior systemic therapies including gemcitabine and fluorouracil. * Patients must have at least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST v1.1). * The score of ECOG for performance status is 0 to 2. * Organ functions and coagulation function must meet the basic requirements. * Patients with childbearing potential must use effective contraception during the treatment and for 6 months after the last dose of treatment. Exclusion Criteria: * History of other primary malignant tumors * Active metastasis to brain or meninges * Active acute or chronic inflammatory skin disease, history of Steven-Johnson syndromes * History of active or chronic corneal and conjunctival diseases, or other clinically significant ocular diseases that affect the ophthalmic monitoring of the investigational drug * Received certain anti-tumor therapies or strong CYP3A4 inhibitors and have not complete the wash-out period, or have not fully recovered from major surgery * AEs due to prior anti-tumor therapy(ies) that have not resolved to ≤Grade 1 per CTCAE v5.0 * Presence of ≥Grade 2 peripheral neuropathy per CTCAE v5.0 * Poorly controlled pleural and peritoneal effusion or pericardial effusion * Severe cardiac dysfunction within 6 months before enrollment * History of ventricular tachycardia, or torsade des pointes * Uncontrolled or poorly controlled hypertension * Compression fractures of the spine that have not been treated with surgery and/or radiation therapy, or have not been stable within 2 weeks before randomization * Pulmonary embolism or deep vein thrombosis within 3 months prior to the first dose of study drug. * Patients with high risk of bleeding per investigator's judgement. * Patients who have active infection including but not limited to hepatitis B, hepatitis C, AIDS, or syphilis. * Active uncontrolled bacterial, viral, fungal, rickettsial, or parasitic infection. * Moderate to severe dyspnea at rest, severe primary lung disease, interstitial lung disease, or pneumonia. * Uncontrolled pain due to cancer * Active or history of autoimmune disease that requiring systemic hormone therapy * History of hypersensitivity to any component of the investigational product. * Other situations that are not suitable to participate a clinical trial per investigator's judgement