This Phase III, randomized, double-blind study compares the efficacy and safety of SCTB14 versus pembrolizumab as first-line treatment in patients with driver gene-negative, TPS ≥10% locally advanced or metastatic non-small cell lung cancer (NSCLC). The primary objective is to assess superiority of SCTB14 over pembrolizumab in prolonging progression-free survival. Safety will be closely monitored.

Inclusion Criteria:

1. Voluntarily sign the written informed consent form prior to screening.
2. Age ≥ 18 years, both male and female.
3. ECOG Performance Status score of 0 to 1.
4. An expected survival of ≥ 3 months.
5. Histologically or cytologically confirmed, unresectable locally advanced (Stage IIIB/IIIC) or metastatic (Stage IV) Non-Small Cell Lung Cancer (NSCLC) that is not amenable to curative surgery or radical concurrent/sequential chemoradiotherapy.
6. For subjects with non-squamous cell carcinoma, as well as non-smoking subjects with squamous cell carcinoma containing mixed adenocarcinoma components, confirmation of the absence of EGFR sensitizing mutations or ALK gene rearrangements from tumor tissue is required prior to enrollment.
7. Subjects must provide a histology sample suitable for PD-L1 testing, with a Tumor Proportion Score (TPS) ≥ 10%.
8. No prior systemic anti-tumor therapy for the studied disease.
9. At least one measurable non-CNS lesion according to RECIST v1.1 criteria.
10. Adequate function of major organs.

Exclusion Criteria:

1. Known actionable driver gene mutations such as ROS1 fusion, BRAF V600E mutation, NTRK fusion, MET exon 14 skipping mutation, and RET fusion mutation.
2. Received non-specific immunomodulatory therapy or immunosuppressive drugs within 2 weeks before the first dose; received traditional Chinese medicine with antineoplastic indications within 1 week before the first dose.
3. Prior thoracic radiotherapy; or local anti-tumor therapy within 2 weeks before first dosing.
4. Prior treatment with antitumor immunotherapy, antiangiogenic therapy, or other small molecule tyrosine kinase inhibitor (TKI)-based antitumor drugs.
5. subjects with metastasis or compression involving the brainstem, meninges, or spinal cord, or those with active CNS metastases or multiple brain metastases.
6. Imaging demonstrates tumor invasion of major blood vessels, significant necrosis or cavitation within the primary tumor lesions, or the presence of lymphangitic carcinomatosis.
7. Imaging demonstrates tumor invasion or compression of adjacent vital organs or carries a risk of developing an esophagotracheal fistula or esophagopleural fistula.
8. History of hypertensive crisis or hypertensive encephalopathy, or the presence of uncontrolled hypertension despite medication, or poorly controlled diabetes despite pharmacotherapy.
9. A history of arterial thrombosis, deep vein thrombosis, cerebral infarction, transient ischemic attack, or significant vascular disease within 6 months prior to enrollment.
10. A history of myocardial infarction, unstable angina, cardiac insufficiency with New York Heart Association (NYHA) class ≥ III, or severe arrhythmia uncontrolled by medication within 6 months prior to enrollment.
11. The presence of any active autoimmune disease or a history of autoimmune disease with an anticipated recurrence.
12. A history of esophageal/gastric varices, severe ulcer, abdominal fistula, intra-abdominal abscess, gastrointestinal perforation and/or fistula, acute gastrointestinal bleeding, intestinal obstruction, or extensive intestinal resection within 6 months prior to the first dose.
13. A history of bleeding tendency, high bleeding risk, or coagulation dysfunction,.
14. The presence of other malignant tumors.
15. Toxicities from prior neoadjuvant/adjuvant therapy, surgery, radiotherapy, or other previous antitumor treatments have not recovered to Grade 0-1.
16. Receipt of a live or attenuated vaccine within 4 weeks prior to the first dose, or a plan to receive a live or attenuated vaccine during the study period; however, the use of inactivated vaccines is permitted.
17. Presence of any of the following infectious conditions: a) severe infection within 4 weeks prior to the first dose; b) active infection within 2 weeks prior to enrollment; c) active tuberculosis; d) positive HIV antibody; e) active hepatitis B or C; f) known active syphilis.
18. Major surgery planned or anticipated during the study period, or unhealed tissue present before enrollment..
19. Presence of symptomatic or recurrent pleural effusion, pericardial effusion, or ascites requiring drainage.
20. A history of non-infectious pneumonia requiring treatment or the presence of interstitial lung disease
21. A history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation.
22. Known hypersensitivity to any component of the investigational drug or a documented history of severe hypersensitivity reactions to any other monoclonal antibody.
23. Current participation in another clinical trial, with the exception of observational (non-interventional) studies or the follow-up phase of an interventional trial.
24. Pregnancy or lactation in female subjects.
25. A known history of alcohol or drug addiction, psychiatric disorders, or drug abuse in the subject.
26. Tumor-induced conditions or symptoms associated with a high medical risk.
27. Any other condition deemed by the investigator to be inappropriate for enrollment.