Washington: Two kids, who were suffering from an aggressive form of childhood leukemia, had a complete remission after they were treated with a novel cell therapy that reprogrammed their immune cells to rapidly multiply and destroy malignant cells.
7-year-old Emily Whitehead, was featured in news stories in December 2012 after the experimental therapy led to her dramatic recovery after she relapsed following conventional treatment.
11 months after receiving bioengineered T cells that zeroed in on a target found in this type of leukemia, called acute lymphoblastic leukemia (ALL), Emily is now healthy and cancer-free.
The other patient, a 10-year-old girl, who also had a complete response to the same treatment, suffered a relapse two months later when other leukemia cells appeared that did not harbour the specific cell receptor targeted by the therapy.
"This study describes how these cells have a potent anticancer effect in children," said co-first author Stephan A. Grupp, M.D., Ph.D., of The Children`s Hospital of Philadelphia, where both patients were treated in this clinical trial.
The current study builds on Grupp`s ongoing collaboration with Penn Medicine scientists who originally developed the modified T cells as a treatment for B-cell leukemias.
The new study used a relatively new approach in cancer treatment: immunotherapy that manipulates immune system to increase its cancer-fighting capabilities. Here the researchers engineered T cells to selectively kill another type of immune cell called B cells, which become cancerous.
The researchers removed some of each patient`s own T cells and modified them in the laboratory to create a type of CAR (chimeric antigen receptor) cell called a CTL019 cell. These cells are designed to attack a protein called CD19 that occurs only on the surface of certain B cells.
By creating an antibody that recognizes CD19 and then connecting that antibody to T cells, the researchers created in CTL019 cells a sort of guided missile that locks in on and kills B cells, thereby attacking B-cell leukemia.
The research has been published in The New England Journal of Medicine.