Non-ICANS neurological complications after CAR T-cell therapies: recommendations from the EBMT Practice Harmonisation and Guidelines Committee

Neurological complications are an important concern in patients undergoing chimeric antigen receptor (CAR) T-cell therapy. Consensus guidelines inform the management of immune effector cell-associated neurotoxicity syndrome (ICANS). However, these guidelines are based on the early clinical experience with CD19 targeting CAR T cells in B-cell malignancies. In contrast, there are so far no published best practice recommendations on the current management of other non-classical neurological complications, which frequently develop after CAR T-cell infusion and cause clinically significant neurotoxicity. These non-classical neurological complications could be more prevalent because of additional CAR T-cell targets (eg, B cell maturation antigen [BCMA]), widened access, new indications in clinical development (including solid tumours in the CNS), and long-term follow-up. In this Review, the European Society for Blood and Marrow Transplantation (EBMT) Practice Harmonisation and Guidelines Committee provides recommendations on the management of CAR T-cell associated neurological complications that occur after treatment with the licensed CD19 and BCMA CAR T cells, as well as neurological toxicities that are emerging with CAR T cells in clinical trials for solid and haematological cancers. We address movement and neurocognitive toxicity, cranial nerve palsies, tumour inflammation-associated neurotoxicity, stroke, myelopathy, peripheral neuropathy, Guillain–Barré syndrome, fludarabine-associated neurotoxicity, and provide guidance on the psychological support for patients. CNS infections were excluded. The guidelines were developed based on the currently available literature and expert opinion. Recommendations are provided when possible, and areas for further research are highlighted to provide a framework to improve patient care.