Dr. O'Brien on CAR T Cells in CLL

Susan M. O’Brien, MD, a hematologist/oncologist at the University of California, Irvine Health, discusses the potential for chimeric antigen receptor (CAR) T-cell therapy in the treatment of patients with chronic lymphocytic leukemia (CLL).

Immunotherapy in the form of CAR T cells has made an impact in hematologic malignancies, particularly in lymphoma and acute lymphocytic leukemia. While this treatment certainly has activity in CLL, it has not proved as effective as it has in those other diseases, O’Brien says.

CAR T-cell therapy works by redirecting the body’s own T cells to attack the cancer; however, in CLL, the patient’s T cells tend to become exhausted and consequently, are unable to function properly. On the other hand, O’Brien notes, “T cell exhaustion” could also be a result of chemotherapy. Researchers could soon overcome this challenge as they move away from chemotherapy regimens to the use of small molecule inhibitors, which are becoming the standard of care in CLL.

O’Brien does not see CAR T cells replacing these inhibitors in the treatment paradigm unless the toxicity profile is lowered. About 25% of patients who receive CAR T cells end up in the intensive care unit because of treatment-related adverse events.