Immune checkpoint blockade for lung cancer: state of the art

Molecularly-guided therapy has revolutionized lung cancer with dramatic responses in patients with aberrations in EGFR, ALK, and ROS1 (1-3). However, the majority of patients with lung cancer (~70%), lack these targetable driver mutations and have historically been treated with cytotoxic chemotherapy (4). Despite lacking a targetable driver mutation, the majority of patients with lung cancer have an overall higher mutational burden more akin to melanoma, which presents an opportunity to unleash the host immune system against tumor neoantigens (5,6). With an increasing appreciation of the role the adaptive immune system plays in lung cancer, the development of therapies to target maladapted immunological pathways such as CTLA-4 and programmed cell death protein 1 (PD-1; CD279)/programmed death-ligand 1 (PD-L1; CD274) have ushered in a new era for these patients (7-9)