This study targets patients with in first-line treatment of advanced NSCLC， enrolling 60-84 participants. Patients will receive Arm 1: JS207 (10 mg/kg or 15 mg/kg, IV, D1) + Pemetrexed (500 mg/m2 IV, D1) + a platinum (carboplatin AUC 5, D1 or cisplatin 75 mg/m2, D1), Q3W, for 4 cycles followed by JS207 (10 mg/kg or 15 mg/kg, IV, D1) + pemetrexed (500 mg/m2 IV, D1), Q3W, until meeting the treatment withdrawal criteria. Arm 2: JS207 (10 mg/kg or 15 mg/kg, IV, D1) + Paclitaxel (175 mg/m2 IV, D1) + a platinum (carboplatin AUC 5, D1 or cisplatin 75 mg/m2, D1), Q3W, for 4 cycles followed by JS207 (10 mg/kg or 15 mg/kg, IV, D1), Q3W, until meeting the treatment withdrawal criteria.The study aims to assess the safety, tolerability, and preliminary efficacy of JS207 combination therapy.

Inclusion Criteria:

1. Age between 18 and 75 years old (both 18 and 75 years old included) at the time of signing the informed consent form, applicable to both males and females.
2. Locally advanced (stage IIIB/IIIC), metastatic or recurrent non-small cell lung cancer (NSCLC) confirmed by histology or cytology, which is not eligible for radical surgery or radical chemoradiotherapy.
3. History of no systemic antitumor therapy for Metastatic or recurrent NSCLC; for subjects who have received adjuvant/neoadjuvant/consolidation therapy (Chemotherapy, radiotherapy, or other therapy), they can be enrolled if the interval between the last treatment and recurrence is more than 6 months.
4. Tissue samples are required for PD-L1 test. New tissue samples are preferred. If new tissue samples are not available, archived samples can be provided.
5. According to the RECIST v1.1 criteria, the subject has at least 1 measurable lesion.
6. Performance status score of 0-1 according to the Eastern Cooperative Oncology Group (ECOG) scale.
7. Expected survival period ≥ 12 weeks.
8. The function of important organs meets the requirements of the protocol.
9. Female subjects of childbearing potential, and male subjects whose partners are females of childbearing age, need to adopt a highly effective contraceptive measure during the study treatment period and for at least 6 months after the last administration.
10. Voluntarily joining this study, signing the informed consent form, having good compliance, and cooperating with the follow-up.

Exclusion Criteria:

1. Histopathologically or cytopathologically confirmed to have combined neuroendocrine (including small cell lung cancer and large cell neuroendocrine carcinoma) components.
2. Treatment received as listed in the protocol, including immunologically mediated treatment; drugs targeting the anti-VEGF pathway, etc.
3. Having an obvious bleeding tendency or a history of severe coagulation dysfunction.
4. Gastrointestinal perforation, intra-abdominal fistula or intra-abdominal abscess occurred within 6 months before the first administration, or currently having high-risk factors for perforation/fistula formation of the hollow viscus as judged by the investigator.
5. Having a serious, unhealed or ruptured wound, active ulcer or untreated fracture.
6. Having uncontrolled hypertension, or a history of hypertensive crisis or hypertensive encephalopathy.
7. Expected that the toxicity of previous anti-tumor treatment has not recovered to ≤ grade 1 according to the Common Terminology Criteria for Adverse Events (CTCAE).
8. Known allergy to the investigational drug or its excipients, pemetrexed, platinum drugs (carboplatin/cisplatin), or known history of ≥ grade 3 allergy to antibody drugs