Research Breakthrough Offers Promising Leads in Cancer Treatment
Researchers at the University of Pennsylvania Medical Center have published preliminary research suggesting new avenues for treating a difficult disease. The research, published in the August 10th online edition of the New England Journal of Medicine, highlighted a new technology whereby genetically enhanced immune cells were used to treat patients with a type of chronic leukemia.
The researchers, led by Dr. David Porter, used a new technique whereby patients with chronic lymphoblastic leukemia had some of their own blood removed, and a type of immune cell called a killer T cell was separated from the blood sample. These T cells were then genetically modified in the lab to enhance their "killing" ability, and reinjected into the patients.
T cells are designed to recognize foreign organisms in our bodies, and kill them. However, these immune cells do not recognize cancer cells, and therefore are not normally able to kill them. Researchers in this small study inserted a therapeutic gene into these T cells, and put them back into the leukemia patient's bloodstream.
While only three patients were enrolled in this study, the results were startling. In two cases, patients achieved 100% remission (i.e. no cancer cells remaining) while the third patient achieved a 70% reduction in cancer cells. Additionally, the genetically modified T cells were still able to be detected in these patients' blood streams six months after initial treatment; in theory, this means that if the leukemia were to recur, the T cells would still be available to attack the cancer cells.
The study was very small, and results, while encouraging, are still considered preliminary. The researchers were almost unable to complete this study due to a paucity of funding; private donations were solicited in order to make this study happen.
The researchers, while very excited by the trend of this research, urge caution in reading too much into the results. One of the side effects of this treatment is the depletion of the body's B cells, another type of immune cell which produces antibodies which the body uses to fight infection. In an editorial discussing this study, Dr. Walter Urba and Dr. Dan Longo, state: "Only with the more widespread clinical use of chimeric antigen–receptor T cells will we learn whether the results reported by Porter et al. reflect an authentic advance toward a clinically applicable and effective therapy or yet another promising lead that runs into a barrier that cannot be easily overcome."