Checkpoint inhibition in cancer

Background The introduction of immune checkpoint inhibitors (ICI) into the therapeutic landscape in oncology over the last decade represents a fundamental advancement in cancer immunotherapy. Objectives We review the mechanism of action of ICI and their current use in the systemic therapy of various cancers. Materials and methods Relevant articles were identified in the PubMed database. Clinical trial information was extracted from the Clinicaltrials.gov registry; information on drug approvals were obtained from the European Medicines Agency and the U.S. Food and Drug Administration databases. Conclusions Although substantial improvements in the treatment of many types of cancer have been achieved by ICI, durable responses and long-term survival can only be observed in a small number of patients. The development of predictive biomarkers to maximize efficacy and minimize immune-related toxicity, in addition to new combination regimens, may help unleash the full potential of ICI in cancer immunotherapy.