A Study to Evaluate the Efficacy and Safety of MRG003 in Patients With EGFR-Positive Advanced Non-Small Cell Lung Cancer

Inclusion Criteria: * Willing to sign the ICF and follow the requirements specified in the protocol. * Age: ≥18 years，both genders. * Expected survival time≥6 months. * Patients with histologically confirmed advanced non-small cell lung cancer, and without histologically confirmed small cell lung cancer (SCLC). * Positive EGFR expression in tumor specimen. * Failed in the prior second-line or above standard of care therapies. * Archival or biopsy tumor specimens should be provided. * Patients must have measurable lesions according to the Response Evaluation Criteria In Solid Tumors (RECIST v1.1). * ECOG performance score 0 or 1. * AEs related to prior systemic chemotherapy and radical/extensive radiotherapy have recovered to ≤ Grade 1 based on National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 (NCI CTCAE V5.0). * No severe cardiac dysfunction with left ventricular ejection fraction (LVEF) ≥ 50%. * 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 hypersensitivity to any component of the investigational product. * No documented progression after prior treatment, or recurrence during or after prior treatment. * Received radiotherapy, chemotherapy, biologicals, immunotherapy or other anti-tumor drugs within 4 weeks prior to the first dose of study treatment. * Presence of central nervous system metastasis. * Patients with significant clinical symptoms such as pleural, abdominal or pericardial effusion requiring puncture drainage prior to the first dose of study drug. * Any severe or uncontrolled systemic disease judged by the investigator. * Patients with poorly controlled heart diseases. * Evidence of active infections, including Hepatitis B, Hepatitis C or human immunodeficiency virus (HIV) infection. * Active bacterial, viral, fungal, rickettsial, or parasitic infection requiring systemic therapy. * Prior history of other primary malignancies. * History of the following ophthalmologic abnormalities: severve dry eye syndrome; keratoconjunctivitis sicca; severe exposure keratitis; any other condition that may increase the risk of corneal epithelial damage. * History of severe skin disease requiring interruption of previous EGFR targeted therapy; or chronic skin disease requiring oral or intravenous therapy. * History of interstitial lung disease (ILD) or pneumonitis, severe chronic obstructive pulmonary disease, severe pulmonary insufficiency, symptomatic bronchospasm, etc. * Pulmonary radiotherapy \> 30 Gy within 6 months prior to first dose of study drug. * Pulmonary embolism or deep vein thrombosis within 3 months prior to the first dose of study drug. * Patients with active autoimmune disease or history of autoimmune disease, who are using immunosuppressive agents or systemic hormone therapy and still receiving within 2 weeks prior to enrollment. * History of allogeneic tissue or solid organ transplant. * Female patients with a positive serum pregnancy test or who are breast feeding or do not agree to take adequate contraceptive measures during the treatment and for 6 months after the last dose of study treatment. * Active uncontrolled concomitant diseases that might limit patient's compliance with study requirements, or compromise patient's ability to provide written informed consent. * Other conditions inappropriate for participation in this clinical trial, at the discretion of the investigator.