Dr. Brentjens on the Side Effects of CAR-Modified T Cells

Renier J. Brentjens, MD, PhD, Leukemia Service, Memorial Sloan-Kettering Cancer Center, discusses the side effects of chimeric antigen receptor(CAR)—modified T cells when used to treat B-cell malignancies.

Brentjens says that only patients with a significant amount of disease in their bone marrow developed fevers, low blood pressure, and high heart rate.

The symptoms are likely caused by cytokines, Brentjens says, which are hormones that are secreted by the T cells. When the T cells are infused into the patient, they go into the marrow, recognize the tumor cells, and become activated. Once T cells are activated, they secrete cytokines, Brentjens says.

Brentjens says patients with a large amount of tumor cells require more T cells to activate, resulting in more cytokine secretion. Patients that only have a slight amount of disease left will not have high cytokine levels, and thus, no side effects.

Brentjens says this correlation has led doctors to treat patients with CAR-modified T cells only when they have the minimal amount of disease.