Pharmacokinetically-guided on the Individualization of Pembrolizumab Administration in the Treatment of Lung Cancer

Inclusion Criteria: 1. cytologically or histologically confirmed primary NSCLC; 2. Stage IV primary NSCLC according to the International Association for the Study of Lung Cancer (IASLC) TNM Eighth Edition; 3. There must be at least one evaluable lesion judged according to RECIST1.1; 4. No sensitive mutation in EGFR and negative ALK rearrangement; 5. ≥18 years old; 6. The Eastern Cooperative Oncology Group (ECOG) physical status score was 0-2; 7. Life expectancy of more than 3 months; 8. Bone marrow and organs (liver and kidney) function well, which can meet the conventional conditions for chemotherapy: neutrophil count ≥1.5×109/ L, platelet count ≥75×109/ L, hemoglobin ≥9g/ dL, total bilirubin ≤1.5×ULN, transaminase ≤2.5×ULN, serum creatinine ≤1.5×ULN or creatinine clearance ≥45ml/min. (ULN: upper limit of normal value); 9. For female subjects of reproductive age, urine or serum pregnancy test should be negative within 7 days prior to receiving the first study drug administration (cycle 1, day 1).If a urine pregnancy test is not confirmed negative, a blood pregnancy test is required;For men, consent must be given to use appropriate methods of contraception or surgical sterilization during the trial and for 8 weeks after the last administration of the experimental drug; 10. Signing the informed consent; 11. Good compliance, follow-up, and voluntary compliance with relevant regulations of the study.- Exclusion Criteria: 1. Small cell lung cancer; 2. Brain metastases with hemorrhage; 3. Currently participating in interventional clinical research and treatment; 4. Past anti-tumor immunotherapy with other anti-PD-1 /PD-L1 monoclonal antibodies; 5. Have received solid organ or blood system transplantation; 6. An active autoimmune disease requiring systemic treatment (e.g., use of palliative drugs, corticosteroids, or immunosuppressants) occurred within 2 years prior to initial administration.Alternative therapies (such as thyroxine, insulin, or physiological corticosteroids for adrenal or pituitary insufficiency) are not considered systemic; 7. having been diagnosed with immunodeficiency or receiving systemic glucocorticoid therapy or any other form of immunosuppressive therapy within 7 days prior to the first administration of the study;Physiological dose of glucocorticoids (≤10 mg/ day of prednisone or its equivalent) is allowed; 8. A history of non-infectious pneumonia requiring glucocorticoid therapy or current interstitial lung disease within 1 year prior to initial administration; 9. A known history of human immunodeficiency virus (HIV 1/2 antibody positive); 10. untreated active hepatitis B