An experimental treatment in which researchers reengineer a patient's own immune system to attack cancer cells seems to have worked in a 7-year old girl named Emma Whitehead. The acute lymphoblastic leukemia that almost claimed Whitehead's life is now in remission.
Whitehead received the treatment, called T-cell immunotherapy, in April. First doctors drew Whitehead's blood, separated out white blood cells called T-cells, and then, using a disabled AIDS virus to transmit genetic material, made the T-cells capable of identifying and attacking leukemia cells.
Finally, the genetically modified T-cells were transfused back into Whitehead, where they went to work wiping out her leukemia to below the level of detection, a process that can itself be deadly.
"This is just one example now of several examples where people can now use immune cells recognizing cancer to reject, and in some cases it's been well shown for 10 years now, that they can cure certain types of cancer with this approach," says Dr. James Yang, a senior investigator at the National Cancer Institute.
"This latest research is about one such retargeting. It's targeting a single molecule, CD-19, that's on certain types of cancers."
Whitehead is one of 12 patients to undergo T-cell immunotherapy for Leukemia at the University of Pennsylvania. Other patients have responded differently, or not at all, to the treatment.
Among them, another pediatric patient initially responded to the treatment, but relapsed one month later. When the leukemia came back, it no longer had the specific CD-19 receptor that doctors had engineered her T-cells to identify on leukemic cells.
"Very often, with acute leukemia when patients relapse, they relapse fairly quickly, and the longer that Emily and other patients go without a relapse, the better the chances the leukemia won't come back, but it is still early in the follow-up," says Dr. David Porter, one of the Penn researchers. Emily is Whitehead's given name, although her family calls her Emma.
"There's a great deal of energy and effort trying to identify other targets on leukemia cells for that situation, but also useful targets that could be on other cancers where you could apply this kind therapy," he said.
Other hospitals are trying similar therapies.