PD-1/PD-L1 Inhibitors for the Treatment of Lung Cancer

Immune checkpoint inhibitors (ICIs) have gained significant attention and traction in the last few years in the treatment of lung cancer and cancers in general. The primary driver of this clinical path is a more reliable route of immune system priming and reduced reliance on toxic anticancer drugs. ICIs, largely made up of PD-1/PD-L1 and CTLA4 protein antibodies, inhibit the immune handshake that falsely allows cancerous cells to be recognized as normal healthy cells. As a result, ICI monotherapy helps the clinician to trigger a potent anticancer effect without relying on drugs that are responsible for a drastic lowering of the cancer patient’s standard of life. The implications of ICI for lung cancer, which currently leads the cancer mortality trend, are important, namely in improving treatment options, reducing the burden of drug side effects, and most certainly improving the survival probability of treated patients. Major considerations for use of ICI include the limited response to ICI in treated patients; the treatment shows remarkable promise in certain patients with susceptibility to immunotherapy, but fails in the majority of treated subjects. This chapter details the immunobiology pertaining to ICI and the pharmacology of currently approved ICI. While ICI therapy is indeed viewed as a breakthrough, its consideration ideally requires the personalized medicine approach. Finally, the question of whether ICI can be a real-world solution for the average patient population including low-to-median income groups is debated.