A Study to Evaluate the Efficacy and Safety of MRG003 in Patients With Recurrent Metastatic Nasopharyngeal Carcinoma

Inclusion Criteria: * Willing to sign the ICF and follow the requirements specified in the protocol. * Age: ≥18 years, ≤75 years * Expected survival time\>3 months. * Patients with histologically confirmed unresectable, radiation-ineligible recurrent metastatic nasopharyngeal carcinoma. * Part A: Metastatic nasopharyngeal carcinoma that has failed or recurred or was intolerant to at least 1 prior line platinum-based systemic chemotherapy and PD-1/PD-L1 inhibitors * Part B: have documented failure of at least 2 prior lines of PD-1 (L1) and therapysystemic chemotherapy, which include at least platinum-based regimen, gemcitabine, taxanes/capecitabine. * Patients must have measurable lesions according to the Response Evaluation Criteria in Solid Tumors (RECIST v1.1). * ECOG performance score 0 or 1. * Organ functions and coagulation function must meet the basic requirements. * No severe cardiac dysfunction with left ventricular ejection fraction (LVEF) ≥ 50%. * Serum or urine pregnancy test negative within 72 hours before the first dose of investigational drug. * Patients with childbearing potential must use effective contraception during the treatment and for 6 months after the last dose of treatment. Exclusion Criteria: * Grade ≥2 peripheral neuropathy per CTCAE v5.0. * Is expected to require surgery or any other form of systemic or local anti-tumor therapy during the study. * Received systemic chemotherapy, targeted therapy, biologics or immunotherapy, or major surgery (exc…