Genetically Engineered T Cells for Childhood Leukemia

May 2013, Vol 4, No 4

Washington, DC—Although still in very early-phase testing in humans, the results of 2 small studies in children suggest that reinfusing autologous genetically engineered T cells can reverse acute lymphocytic leukemia (ALL) in children. Both studies were presented at the 2013 American Association for Cancer Research meeting.

All the children had run out of treatment options and were close to death; 2 had a remarkable recovery after T-cell therapy and remain in complete remission.

The treatment, called anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, entails collecting a patient’s immune T cells and genetically modifying and expanding them in the laboratory, and then reinfusing them back into the patient. The modified T cells attach to the CD19 protein that is expressed by leukemia cells.

The first study included 4 patients who were treated with the anti-CD19 CAR T cells. The 3 children with ALL had previously undergone bone marrow transplantation and their disease had progressed. After treatment, 2 of 3 children with ALL achieved complete responses; the third child had a transient response that is too early to evaluate. The fourth child, who had B-cell lymphoma, did not respond to the T-cell therapy.

“Childhood ALL is the most common malignancy in pediatric patients. The majority of children can achieve remission, but this comes with the price of long therapy, toxicity, and cost, with no guarantee of [a] long-term cure,” said Daniel W. Lee III, MD, Clinical Fellow, Center for Cancer Research, National Cancer Institute.

The second study included 5 pediatric patients with ALL with CAR T-cell therapy; 4 of them achieved complete responses, said lead investigator David M. Barrett, MD, PhD, Clinical Associate in Pediatrics, The Children’s Hospital of Philadelphia, PA. Three complete responses have been durable; the longest response was 12 months, and 1 response was transient. The fifth patient did not respond.

“The main take-away message is that this therapy is effective in pediatric ALL....This therapy has the potential to save lives when chemotherapy cannot,” Dr Barrett said.

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