Envafolimab as First-line Treatment of Aged Patients in Advanced NSCLC

Inclusion Criteria: * Signed written informed consent. * Age strictly at least 70 years. * Cytologically or histologically proven NSCLC(adenocarcinoma, epidermoid carcinoma, large-cell carcinoma) of locally advanced (stage IIIb/IIIc), metastatic, or relapsing (stage IV) according to the American Joint Committee on Cancer Staging Handbook. * Presence of at least one measurable target lesion (RECIST rules) in a non irradiated region. * No previous systemic chemotherapy for lung cancer. * PD-L1≥50% in tissue samples detected by immunohistochemistry. * PS 0 or 1. * Life expectancy sup 12 weeks. * Normal hematologic function. Exclusion Criteria: * EGFR-sensitive mutations or ALK rearrangements * Previous treatment with immune checkpoint inhibitors * Presence of symptomatic brain metastases； * Chinese patent medicine with anti-lung cancer indications or immunoregulatory drugs (including thymopeptide, interferon and interleukin, except for the local use of pleural effusion control) for systemic treatment； * Another previous or concomitant cancer, except for basocellular cancer of the skin or treated cervical cancer in situ； * Concurrent administration of one or several other antitumor therapies； * Concurrent participation in another clinical trial； * Active autoimmune disease requiring systemic treatment occurred within 2 years prior to initial； * Systemic glucocorticoid therapy or any other form of immunosuppressive therapy within 7 days prior to initial administration； * Contraindication to the study drugs； * Has not fully recovered from toxicity and/or complications caused by any intervention prior to the commencement of treatment (i.e., grade 1 or baseline, excluding fatigue or hair loss); * A history of human immunodeficiency virus (HIV) infection; * Untreated active hepatitis B (defined as HBsAg positive and HBV-DNA copy number detected greater than the upper limit of normal value in the laboratory of the research center); * Active HCV infected; * Recent vaccination within 30 days before the first administration (cycle 1, day 1); * Other severe concurrent disorders that occurred during the prior six months before enrollment (myocardial infection, severe or unstable angor, NYHA class 3 or 4 congestive heart failure, transient or constituted cerebral ischemic attack, psychiatric or neurological disorders preventing the patient from understanding the trial, uncontrolled infections).