[Toxicity of immune checkpoints inhibitors]

Anti-tumoral immunotherapy is currently the basis of a profound modification of therapeutic concepts in oncology, in particular since the arrival of immune checkpoint inhibitors (ICI). In addition to their efficacy profile, these immune-targeted agents also generate adverse events. With the increasing use of ICI for a growing number of tumor types, awareness of immunotherapy-related adverse events is essential to ensure prompt diagnosis and effective management of these potentially serious adverse events.

Cytotoxic T-lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) are two co-inhibitory receptors that are expressed on activated T cells against which therapeutic blocking antibodies have reached routine clinical use. Immune checkpoint blockade can induce inflammatory adverse effects, termed immune-related adverse events (irAEs), which resemble autoimmune disease. Though severe irAEs remain rare, they can be fatal if not diagnosed and treated in an appropriate manner.

Additional studies are needed to better understand the clinical characteristics and chronology of these adverse effects and to clarify their pathophysiological mechanisms.