PDCD1 and non-small cell lung carcinoma: Pembrolizumab, a humanized IgG4 antibody against PD‐1, was studied in the KEYNOTE‐001 phase I study at various doses and administration schedules to examine safety in a cohort of 495 patients that were either treated or untreated with locally advanced or metastatic NSCLC (irrespective of histology) 51.