The Other Side of CAR T-Cell Therapy: Cytokine Release Syndrome, Neurologic Toxicity, and Financial Burden.

Immune effector cells, including T cells and natural killer cells, which are genetically engineered to express a chimeric antigen receptor (CAR), constitute a powerful new class of therapeutic agents to treat patients with hematologic malignancies. Several CAR T-cell trials have shown impressive remission rates in patients with relapsed/refractory hematologic cancers. Although the clinical responses of these agents in hematologic malignancies have been very encouraging, they have also produced substantial morbidity and occasionally mortality resulting from toxicity. With more experience and collaboration, hopefully the toxicities and the costs will come down, increasing the availability of CAR T cells to patients in need.