RecruitingPhase 2Drug trialPALACE: Cemiplimab Trial According to ctDNA LevelsThis is an open-label, non-randomised, phase II, multicenter clinical trial. 63 stage IV or stage IIIB/C not candidates for definitive chemo/radiotherapy or surgical resection non-small cell lung cancer (NSCLC) per the 8th edition TNM with no prior systemic anti-cancer therapy will be enrolled in this trial to determine whether therapy decision making based on ctDNA analysis improves overall survival.