Immune checkpoint blockade: the hope for immunotherapy as a treatment of lung cancer?

Abstract

Over the past 20 years, immunotherapy has not played a role in the treatment of lung cancer outside of clinical trials. Early trials with vaccines yielded promising results, but phase III trials have yet to show an improvement in survival. Recently, immune checkpoint pathway inhibitors have yielded exciting and consistent activity across this class of antibodies. However, phase III trials are now ongoing. Currently, the hope of bringing immunotherapy to lung cancer patients lies in this class of drugs. Only time will show us if these antibodies will yield an improvement in long-term survival. This review will focus on checkpoint pathway inhibitors that have completed early-phase trials.

Copyright © 2014 Elsevier Inc. All rights reserved.

Figures

Figure 1

There are two different ways of blocking the PD-1 pathway. By blocking PD-L1, the antibody blocks the binding of PD-L1 to its known receptors, PD-1 and B7.1. However, the antibody does not block the binding of PD-1 to its other ligand PD-L2. Alternatively by blocking PD-1, an anti–PD-1antibody blocks the binding of PD-1 to both of its ligands, PD-L1 and PD-L2. However, the anti–PD-1antibodies do not block the binding of PD-L1 to B7.1. These differences in blockade may or may not be clinically relevant. Further studies are needed to compare the efficacy and possible toxicity differences in these two ways of blocking the same pathway.