Researchers at the University of Pennsylvania have recently reported a potential breakthrough in the treatment of chronic lymphocytic leukemia (CLL), a cancer of B-cells of the immune system. The researchers removed some T-cells from three patients with CLL and genetically modified them to recognize the leukemic tumor cells. When the modified cells T-cells were re-infused into the patients they vigorously attacked the leukemic tumor cells, sending the cancer into complete remission in two patients and significantly improving the condition of the third patient. Significantly, the genetically modified T-cells underwent clonal expansion within the patients, leading to over a 1000-fold expansion of activated T-cells that lasted more than six months.
These results should be viewed as preliminary. Only three patients have been treated so far and the long-term efficacy of the technique is not yet known. Nevertheless, the idea of activating a patient’s own immune system to attack specific cancer cells is extremely attractive, and might be applicable to other cancers as well. We’ll be keeping an eye on this.