Neurologic toxicities following adoptive immunotherapy with BCMA-directed CAR T cells

TO THE EDITOR:

Chimeric antigen receptors (CARs) endow an autologous T-cell population with major histocompatibility complex–unrestricted killing activity against tumor antigens including CD19 or the B-cell maturation antigen (BCMA). Neurologic toxicities ranging from confusion to severe cerebral edema are well described for CD19-directed CAR T cells and are denoted as immune effector cell–associated neurotoxicity syndrome (ICANS).¹ In BCMA-directed CAR T cells, the pivotal clinical trials for multiple myeloma suggest unique toxicities including parkinsonism-like symptoms.^2,3 Because such therapies only recently gained commercial approval, real-world data remain scarce. We present our institutional experience on incidence, presentation, management, and outcome of neurotoxicities after BCMA-directed CAR T-cell therapy.

With institutional review board approval, we retrospectively searched our institutional database at Massachusetts General Hospital for multiple myeloma treated with BCMA-directed CAR T cells between 2016 to 2023. Toxicities and outcome were evaluated...