The CTL019 therapy, formerly called CART19, represents a new approach in cancer treatment. T cells are the workhorses of the immune system, recognizing and attacking invading disease cells. However, cancer cells fly under the radar of immune surveillance, evading detection by T cells. CAR T cells (chimeric antigen receptor T cells) are engineered to specifically target B cells, which become cancerous in certain leukemias, such as ALL and CLL, as well as types of lymphoma, another cancer of the immune cells.
CD19 is a protein found only on the surface of B cells. By creating an antibody that recognizes CD19, and physically connecting that antibody to T cells, the researchers have created a guided missile that locks in on and kills B cells, thereby attacking B-cell leukemia.
In using the CTL019 treatment in his pediatric patient, Grupp found that the very activity that destroyed leukemia cells also stimulated a highly activated immune response called a cytokine release syndrome. The child became very ill and had to be admitted to the intensive care unit.
Grupp and his team decided to counteract these toxic side effects by using 2 immunomodulating drugs that blunted the overactive immune response and rapidly relieved the child's treatment-related symptoms. These results were effective enough that this approach is now being successfully incorporated into CTL019 treatments for adults as well.
The immunomodulating drugs did not interfere with the CTL019 therapy's anti-leukemia benefits, which have persisted 6 months after the infusion of cell therapy. This persistence is essential, because the engineered T cells remain in the patient's body to protect against a recurrence of the cancer.
"These engineered T cells have proven to be active in B cell leukemia in adults," said Grupp. "We are excited to see that the CTL019 approach may be effective in untrea
|Contact: Rachel Salis-Silverman|
Children's Hospital of Philadelphia