By Kim Polacek, APR, CPRC - February 10, 2020
Cellular immunotherapy is a fast-growing area of oncology. The personalized treatments use a patient’s own immune system and cells to treat cancer. One of the most recent therapies approved by the Food and Drug Administration in this field is chimeric antigen receptor T-cell therapy, or CAR T therapy. For this therapy, a patient’s T cells are removed from their blood and sent to a lab where modification occurs to multiply the number of cells and attach a receptor to each. The receptor acts as a GPS giving the T cells the ability to recognize and eliminate tumor cells once infused back in a patient’s body.
CAR T has proved to provide durable remission for patients with leukemia and lymphoma.
However, it is not without side effects. Some patients experience cytokine release syndrome, which has flu-like symptoms such as fever, chills and nausea, and neurological events like confusion or difficulty speaking. While these side effects can be managed, it has sparked many researchers to look for alternative cellular immunotherapies that are less toxic.
Enter the natural killer (NK) cell. NK cells are white blood cells that are part of the immune system. They attack virally infected cells and can detect and control early signs of cancer. In a new study published by the New England Journal of Medicine, researchers at MD Anderson Cancer Center in Houston, Texas, investigated attaching a chimeric antigen receptor to NK cells for a cellular immunotherapy similar to CAR T therapy.
They tested the CAR NK therapy in 11 patients and found eight had a positive response to the therapy with seven going into complete remission. More importantly, the researchers said the participants did not develop any of the major side effects of CAR T therapy.
The NK cells used for this study came from allogenic (donor) cord blood, and not the patient. Moffitt Cancer Center immunologist Dr. Daniel Abate-Daga says the study is promising but it is not clear if this approach will be effective for treating other cancer types.
“But the fact that they report long-term persistence of HLA-mismatched cells is encouraging for the development of other allogeneic adoptive immunotherapies, including engineered NK cells and possibly other cell types such as Gamma/Delta T cells,” said Abate-Daga.