Langer CJ, et al. Carboplatin and pemetrexed with or without pembrolizumab for advanced, non -squamous non -small -cell lung cancer: a randomized phase 2 cohort of the open- label KEYNOTE -021 study .The Lancet 2016. http://dx.doi.org/10.1016/S1470 -2045(16)30498- 3 25.