Trial of Chidamide in Combination With Envafolimab in Patients With PD-1 Inhibitor Resistant Advanced NSCLC.

This study including two phases: (1) Pre-test Phase, 3\~6 patients will be enrolled and receive 20 mg Chidamide BIW and 400 mg Envafolimab Q4W. The main object of pre-test phase is to evaluate the preliminary safety and tolerability of Chidamide when in combination with Envafolimab. (2) Formal experiment Phase, 63 patients will be enrolled and receive 30 mg Chidamide BIW and 400 mg Envafolimab Q4W, to evaluate the efficacy and safety of Chidamide when in combination with Envafolimab in patients with PD-1 inhibitor resistant advanced NSCLC. This study is also to explore the gene expression and variation, PD-L1 and HDAC2 proteins expression levels in tumor tissue samples, the circulating tumor DNA (ctDNA) in plasma, and the potential correlation between peripheral blood cytokines and clinical preliminary efficacy and safety.