Neurological updates: neurological complications of CAR-T therapy

Chimeric antigen receptor (CAR)-expressing T cells now offer an effective treatment option for people with previously refractory B cell malignancies and are under development for a wide range of other tumours. However, neurological toxicity is a common complication of CAR-T cell therapy, seen in over 50% of recipients in some cohorts. Since 2018, the term immune effector cell-associated neurotoxicity syndrome (ICANS) has been used to describe and grade neurotoxicity seen after CAR-T cells and other similar therapies. ICANS following CAR-T therapy is usually self-limiting but can necessitate admission to the intensive care unit and is rarely fatal. As CAR-T therapies enter routine clinical practice, it is important for neurologists to be aware of the nature of neurological complications. Here, we summarise the clinical manifestations, mechanisms, investigations and recommended treatment of CAR-T-related neurotoxicity, focusing on the licensed CD19 products.