Toxicities Associated with CAR-T Cell Therapies

Chimeric antigen receptor (CAR) T-cell therapy has improved the outcomes of patients with relapsed/refractory B-cell lymphomas, B-cell acute lymphoblastic leukemia, and multiple myeloma. However, CAR-T cell therapy is also associated with distinct toxicities that contribute to morbidity and mortality. A large number of studies now define the different toxicities associated with CAR-T cell therapy and have, in part, clarified their mechanisms. In particular, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are the two main acute toxicity events that occur after CAR-T cell infusion. Other CAR-T-related toxicities occur later after CAR-T cell infusion and include B-cell aplasia, hypogammaglobulinemia, infections, and cytopenias. Infections represent the main cause of non-relapse death observed in patients undergoing CAR-T cell therapy. Second primary malignancies are rare and are mainly represented by myeloid malignancies.