A Study of SI-B001+SI-B003± Chemotherapy in the Treatment of Locally Advanced or Metastatic Non-small Cell Lung Cancer

Inclusion Criteria: 1. Voluntarily sign the informed consent form and comply with the protocol requirements; 2. No gender restrictions; 3. Age ≥18 years and ≤75 years; 4. Expected survival time ≥3 months; 5. Subjects must agree to complete ctDNA testing during the screening period; 6. Histologically or cytologically confirmed locally advanced or metastatic non-small cell lung cancer (NSCLC) patients; 7. Agree to provide archived or fresh tumor tissue samples from primary or metastatic lesions; 8. Must have at least one measurable lesion as defined by RECIST v1.1; 9. Performance status score: ECOG ≤1; 10. Toxicity from prior anti-tumor therapy has recovered to ≤ Grade 1 as defined by NCI-CTCAE v5.0; 11. No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥50%; 12. Organ function levels must meet the requirements without transfusion, albumin, colony-stimulating factors, any cell growth factors, and/or platelet-raising drugs within 14 days before the first dose of the study drug; 13. Coagulation function: International Normalized Ratio (INR) ≤1.5, and activated partial thromboplastin time (APTT) ≤1.5 × ULN; 14. Urine protein ≤1+ or ≤1000 mg/24h; 15. Female subjects of childbearing potential or male subjects with partners of childbearing potential must use highly effective contraception from 7 days before the first dose until 24 weeks after the last dose. Female subjects of childbearing potential must have a negative serum pregnancy test within 7 days before the first dose. Exclusion Criteria: 1. Prior to signing the informed consent form, relevant genetic alterations were indicated; 2. For patients enrolled in Phase II, any of the following conditions apply: a) Patients suitable for and willing to undergo local therapy; b) Patients who have received systemic chemotherapy; 3. Symptomatic brain parenchymal or leptomeningeal metastases, deemed ineligible by the investigator; 4. Participation in any other clinical trial within 4 weeks prior to the administration of this trial's investigational product (based on the last dose date); 5. Use of chemotherapy, biologic therapy, immunotherapy, etc., within 4 weeks or 5 half-lives prior to the first dose, or palliative radiotherapy, small-molecule targeted therapy, or other antitumor treatments within 2 weeks before the first dose; 6. Major surgery (as defined by the investigator) within 4 weeks prior to the first dose; 7. Requirement for systemic corticosteroids or immunosuppressive therapy within 2 weeks before the study drug administration; 8. Pulmonary diseases graded as ≥3 according to NCI-CTCAE v5.0; history of interstitial lung disease (ILD), current ILD, or suspected ILD during screening; 9. Concurrent pulmonary disease resulting in clinically significant respiratory impairment; 10. Unstable thrombotic events requiring therapeutic intervention within 6 months before screening (excluding catheter-related thrombosis); 11. Active infection requiring intravenous anti-infective therapy; 12. Imaging findings indicating tumor invasion or encasement of major thoracic, cervical, or pharyngeal blood vessels, with a risk of bleeding post antitumor therapy; 13. Prior immunotherapy leading to ≥Grade 3 immune-related adverse events (irAE) or ≥Grade 2 immune-related myocarditis; 14. Use of live attenuated vaccines within 4 weeks before the first dose of the study drug; 15. Use of immunomodulatory drugs within 14 days before the first dose of the study drug; 16. Patients at risk of active autoimmune diseases or with a history of autoimmune diseases; 17. History of other malignancies within 5 years before the first dose; 18. Positive for human immunodeficiency virus (HIV) antibodies, active tuberculosis, active hepatitis B virus (HBV) infection, or hepatitis C virus (HCV) infection; 19. Poorly controlled hypertension (systolic blood pressure \>150 mmHg or diastolic blood pressure \>100 mmHg); 20. History of severe cardiovascular or cerebrovascular diseases; 21. Patients with significant serous cavity effusion, symptomatic effusion, or poorly controlled effusion; 22. History of allogeneic stem cell, bone marrow, or organ transplantation; 23. History of hypersensitivity to recombinant humanized antibodies or any excipients of SI-B001 or SI-B003; 24. History of autologous or allogeneic stem cell transplantation; 25. Pregnant or lactating women; 26. Any other condition deemed unsuitable for participation in this clinical trial by the investigator.