Current state and perspectives of CAR T cell therapy in central nervous system diseases

B cell-directed CAR T cell therapy has fundamentally changed the treatment of haematological malignancies, and its scope of application is rapidly expanding to include other diseases such as solid tumours or autoimmune disorders. Therapy-refractoriness remains an important challenge in various inflammatory and non-inflammatory disorders of the CNS. The reasons for therapy failure are diverse and include the limited access current therapies have to the CNS, as well as enormous inter- and intra-individual disease heterogeneity. The tissue-penetrating properties of CAR T cells make them a promising option for overcoming this problem and tackling pathologies directly within the CNS. First application of B cell-directed CAR T cells in neuromyelitis optica spectrum disorder and multiple sclerosis patients has recently revealed promising outcomes, expanding the potential of CAR T cell therapy to encompass CNS diseases. Additionally, the optimization of CAR T cells for the therapy of gliomas is a growing field. As a further prospect, preclinical data reveal the potential benefits of CAR T cell therapy in the treatment of primary neurodegenerative diseases such as Alzheimer's disease. Considering the biotechnological optimizations in the field of T cell engineering, such as extension to target different antigens or variation of the modified T cell subtype, new and promising fields of CAR T cell application are rapidly opening up. These innovations offer the potential to address the complex pathophysiological properties of CNS diseases. To use CAR T cell therapy optimally to treat CNS diseases in the future while minimizing therapy risks, further mechanistic research and prospective controlled trials are needed to assess seriously the disease and patient-specific risk-benefit ratio.