Management of complications of chimeric antigen receptor T-cell therapy: a report by the European Society of Blood and Marrow Transplantation.

Chimeric antigen receptor (CAR) T cells are in standard clinical use to treat relapsed or refractory hematologic malignancies, such as non-Hodgkin lymphoma, multiple myeloma and acute lymphoblastic leukemia. Owing to the rapidly progressing field of CAR T-cell therapy and the lack of generally accepted treatment guidelines, we hypothesized significant differences between European centers in prevention, diagnosis and management of short- and long-term complications. To capture the current CAR T-cell management among European Society for Blood and Marrow Transplantation (EBMT) centers and to determine the medical need and specific areas for future clinical research the EBMT Transplant Complications Working Party performed a survey among 227 EBMT CAR T-cell centers. We received complete servey answers from 106 centers (47%) addressing questions in the areas of product selection, CAR T-cell logistics, management of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome as well as management in later phases including prolonged cytopenias. We identified common patterns in complication management, but also significant variety in clinical management of the centers in important aspects. Our results demonstrate a high medical need for treatment harmonization and future clinical research in the following areas: treatment of steroid-refractory and very severe cytokine release syndrome/neurotoxicity, treatment of cytopenia, early discharge and outpatient management, as well as immunoglobulin substitution.