A Phase II Study of Anti-PD-1 Antibody, Sintilimab, as Second-line Therapy for Biomarker-selected Advanced or Metastatic NSCLC

Inclusion Criteria: * ≥ 18 and ≤ 70 years of age , regardless of gender； * Pathologically confirmed diagnosis of locally advanced or metastatic NSCLC (according to the eighth edition of AJCC staging, IIIB, IIIC, IV), with at least one measurable lesion (RECIST 1.1) * treatment failure after first-line standard treatment (definition of treatment failure: intolerable side effects, disease progression during or after treatment); * No known EGFR sensitive mutations and ALK gene rearrangements. * Tumor tissue samples that meet the testing requirements for biomarker testing can be provided. Testing will be carried out in the central laboratory. * NSCLC that is anti-programmed cell death ligand 1 (PD-L1) positive(TPS PD-L1 expression is ≥1% ), and CD8 expression is ≥20% (pre-treatment samples are sufficient). * ECOG PS: 0-1 * Sufficient organ and bone marrow function as defined below: 1. Routine blood examination: 1. HB≥90g/L; 2. ANC ≥1.5×109/L; 3. PLT ≥90×109/L; 2. Biochemical inspection shall: 1. Total bilirubin ≤ 1.5 ULN; 2. ALT and AST≤2.5ULN; 3. Serum Cr≤1ULN, endogenous creatinine clearance rate\>60ml/min (Cockcroft-Gault); * The international normalized ratio (INR) ≤ 1.5 and partial prothrombin time (PPT or APTT) ≤ 1.5 ULN within the 7 days before enrollment. * Life span expectation over 3 months; * Provide written informed consent; Exclusion Criteria: * Allergic to any ingredients of Sintilimab preparations; or have had severe allergic reactions to other monoclonal antibodies in the past. * Received more than one regimen for the treatment of locally advanced or metastatic NSCLC in the past (except for adjuvant/neoadjuvant chemotherapy that has exceeded the 24-week). * Received any anti-PD-1/PD-L1 antibody, anti-CTLA4 antibody, or other immunotherapy in the past. * Diagnosed other malignant tumors within 5 years before the first administration, excluding radically cured skin basal cell carcinoma, skin squamous cell carcinoma and/or radically excised carcinoma in situ. * Be treated with anti-tumor vaccines or other immunostimulatory anti-tumor drugs (interferon, interleukin, thymosin, immune cell therapy, etc.) within 1 month before enrolled. * Central nervous system metastasis with symptoms.. * Acute or chronic active hepatitis B (defined as positive for hepatitis B virus surface antigen HBsAg during the screening period) or hepatitis C infection. * History of pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, drug-related pneumonia, severely impaired lung function and other lung diseases. * Active tuberculosis (TB), who are receiving anti-tuberculosis treatment or have received anti-tuberculosis treatment within 1 year before the first administration. * People infected with human immunodeficiency virus (HIV) (HIV antibody positive), people with known syphilis infection. * Patients who are considered to be at greater medical risk due to severe, uncontrollable diseases, non-metastatic systemic diseases, or active, uncontrollable infections. * An active autoimmune disease that requires systemic treatment (such as the use * disease-relieving drugs, corticosteroids, or immunosuppressive agents) occurred within 2 years before the first administration. * Have used immunosuppressive drugs within 4 weeks before the first administration, excluding nasal spray, inhaled or other local glucocorticoids or physiological doses of systemic glucocorticoids (ie not more than 10 mg/day prednisone Loose or equivalent doses of other glucocorticoids), allowing temporary use of glucocorticoids for the treatment of asthma, chronic obstructive pulmonary disease and other diseases such as dyspnea symptoms. * Exclude subjects who are expected to require any other form of anti-tumor therapy (including maintenance therapy with other NSCLC drugs, radiotherapy, and/or surgical resection) in the study. * Exclude those who underwent major surgery within 4 weeks before the first medication, those with non-thoracic radiation therapy \>30 Gy within 4 weeks before the first medication, those with chest radiation \>30 Gy within 24 weeks before the first medication, and 2 before the first medication Subjects who received palliative radiation \<30 Gy within a week and who failed to recover from the toxicity and/or complications of these interventions to NCI-CTC AE ≤ 1 degree (except for hair loss and fatigue). Palliative radiotherapy for symptom control is permitted and must be completed at least 2 weeks before the start of treatment with the study drug, and there are no plans for additional radiotherapy to the same lesion. For patients who received radiotherapy 2 weeks before the first administration, all of the following conditions must be met before they can be enrolled: There is no radiotherapy-related toxic reaction, glucocorticoids are not required, and radiation pneumonitis, radiation hepatitis, radioactivity are excluded Enteritis and so on. * Pregnancy or lactation. * Participated in other drug clinical trials within four weeks. * The investigator believes that there are any conditions that may damage the subject or result in the subject not being able to meet or perform the research request.