Overview and management of toxicities of immune checkpoint-blocking drugs

Immunotherapy is considered to be the most important breakthrough in cancer management in the past few years. This success was based on the scientific understanding of immune mechanisms due to improvement in preclinical science and the introduction of new methods of investigation. Immune checkpoint inhibitors (ICIs) are among the most promising drugs in the field of immune-oncology; they represent monoclonal antibodies that modulate the effects of immune checkpoints, such as cytotoxic T lymphocyte Antigen 4 (CTLA-4) and Programmed Cell Death protein 1 (PD-1), which are co-inhibitory signals responsible for immune suppression. Despite clinical benefits, ICIs are immune activating agents that are associated with a number of important side effects (immune-related adverse events-irAEs), attributed to organ-specific inflammation. Herein, we review the toxicities of ICIs, highlighting the importance of early identification and management.