A Study of Sintilimab or Placebo in Combination With Chemotherapy as Second-line Treatment for Patients With Stage IV Nonsquamous Non-small Cell Lung Cancer With Wild-type EGFR After Failure With Platinum-Containing Chemotherapy.

Exclusion Criteria

• •1. ECOG PS \>2;
• •2. Small cell lung cancer and squamous NSCLC;
• •3. EGFR mutation or mutation status unknown;
• •4. Known hypersensitivity or allergy to monoclonal antibody;
• •5. Prior therapy with an anti-programmed cell death (PD)-1, anti-PD-L1, anti-PD-L2, anti-tumor necrosis factor CD137, or anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibody (including any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways);
• •6. Active autoimmune disease, or a documented history of autoimmune disease;
• •7. Treatment with systemic corticosteroids (prednisone≥10mg per day or equivalent dose) or other systemic immunosuppressive medications within 2 weeks prior to the first dose;
• •8. Known history or active human immunodeficiency virus (HIV);
• •9. Known acute or chronic active hepatitis B (HBV DNA positive) infection or acute or chronic active hepatitis C (HCV antibody positive and HCV RNA positive) infection;
• •10. Interstitial lung disease, or history of pneumonitis requiring systemic steroids for treatment;
• •11. Active or poorly controlled severe infection;
• •12. Have serious cardiovascular disease: Symptomatic congestive heart failure (New York Heart Association grade III-IV), unstable angina pectoris, unstable arrhythmia, myocardial infarction or cerebrovascular accident within 3 months before randomization;
• •13. Received thoracic radiation therapy of \>30 Gy within 6 months prior to first dose of study drug;
• •14. Completed palliative radiotherapy within 7 days prior to first dose of study drug;
• •15. Pregnant or lactating women.