This study aims to evaluate the efficacy and safety of RC148 combined with platinum-based chemotherapy versus Tislelizumab combined with platinum-based chemotherapy in participants with locally advanced or metastatic Squamous NSCLC who have not received first-line treatment. Participants will: Take RC148 or Tislelizumab combined with platinum-based chemotherapy until the end of the research.

Inclusion Criteria:

1. Voluntarily participate in the study and signed the Informed Consent Form (ICF).
2. Be willing to and able to participate in the trial and comply with the follow up procedures;
3. Male or female, aged 18-75 years.
4. Expected survival ≥ 3 months.
5. ECOG PS score 0 or 1.
6. Histopathologically or cytologically confirmed locally advanced or metastatic NSCLC not eligible for curative treatment.
7. No prior systemic anti-tumor treatment for advanced or metastatic squamous NSCLC.
8. Sufficient cardiac, bone marrow, hepatic, renal, and coagulation function.
9. Female participants must be postmenopausal, surgically sterilized, or of childbearing potential with a negative blood pregnancy test within 7 days before the first dose. Female participants must agree to use at least one medically approved contraceptive method during the study treatment and for 6 months after the end of the study treatment, and must not donate oocytes or breastfeed during this period. Male participants must agree to use at least one medically approved contraceptive method during the study treatment and for 6 months after the end of the study treatment, and must not donate sperm during this period.
10. At least one measurable lesion outside of the brain according to the RECIST v1.1 criteria.
11. A PD-L1 expression test report that meets the requirements must be provided before enrollment.

Exclusion Criteria:

1. Histopathologically or cytologically confirmed non-squamous non-small cell lung cancer.
2. Squamous NSCLC with known EGFR sensitive mutations and ALK fusions; squamous NSCLC with known driver gene for which first-line approved treatment options exist.
3. Presence of active brain metastases.
4. Imaging at screening shows obvious tumor necrosis and cavitation, and the investigator judges that participation in the study will cause bleeding risk.
5. Chest radiotherapy > 30Gy within 6 months before randomization; palliative local treatment for non-target lesions within 2 weeks before randomization; non-specific immunomodulatory treatment within 2 weeks before randomization; Chinese herbal medicine or proprietary Chinese medicine treatment with anti-tumor indications within 1 week before randomization.
6. History of immunotherapy. Note: For adjuvant/neoadjuvant phases or curative radiotherapy/chemoradiotherapy, PD-L1/PD-1 antibody therapy should be administered only if recurrence or metastasis occurs more than 12 months after the completion of the last medication.
7. Prior systemic anti-tumor treatment other than chemotherapy and PD-1/PD-L1 antibodies.
8. Systemic treatment with corticosteroids or other immunosuppressive drugs within 2 weeks before randomization.
9. Use of any live or attenuated live vaccines within 4 weeks before randomization, or planned during the study.
10. Participation in other clinical trials within 4 weeks before randomization.
11. Major surgery, interventional therapy, or severe trauma within 4 weeks before randomization, or planned major surgery during the study; core needle biopsy or other minor surgery within 7 days before randomization.
12. Participants with history of severe coagulation dysfunction or current intake of anticoagulant drugs.
13. Toxic reactions from prior anti-tumor treatment have not recovered to grade 0-1 as defined by CTCAE version 6.0.
14. Severe acute or chronic infections.
15. Active gastrointestinal bleeding, hemoptysis, peptic ulcer, or hemorrhagic events requiring intervention within 4 weeks before randomization; or presence of severe esophagogastric varices or epistaxis.
16. Severe arterial/venous thrombotic events or cerebrovascular accidents within 6 months before randomization.
17. Active or clinically significant heart disease.
18. Past or current interstitial lung disease, drug-related pneumonia, radiation pneumonitis, severe impairment of lung function, or clinical manifestations or high-risk factors suspected of interstitial lung disease.
19. History of gastrointestinal perforation and/or fistula, history of gastrointestinal obstruction within 6 months before randomization.
20. Presence of systemically diseases that are not stably controlled as judged by the investigator.
21. Active or history of autoimmune diseases with potential for recurrence.
22. Past history of other acquired or congenital immunodeficiency diseases or organ transplantation.
23. Known hypersensitivity or delayed-type hypersensitivity to certain components of the study drug or similar drugs.
24. Presence of symptomatic or intervention-requiring third-space effusions.
25. Other malignant tumors within 5 years before the start of study drug administration, except for malignant tumors that are expected to be cured after treatment.
26. Poor compliance and expected inability to cooperate with the completion of trial procedures.
27. Past or current history of any other diseases, abnormal physical examination findings, or abnormal laboratory examination findings that, in the investigator's judgment, reasonably suggest that the participant has a disease or condition unsuitable for the use of the study drug.
28. Local or systemic diseases not caused by malignant tumors, or diseases or symptoms secondary to tumors.
29. For participants who have used PD-1/L1 inhibitors, prior occurrence of grade 3 or above irAE related to immunotherapy, irAE leading to permanent discontinuation of treatment, grade 2 immune-related cardiotoxicity, or irAE of any grade involving the nervous system or eyes; prior occurrence of adverse events requiring treatment with immunosuppressive drugs other than corticosteroids, or recurrence of adverse events during previous immunotherapy requiring systemic use of corticosteroids again.