HEALTHWATCH

PHILADELPHIA, PA — Researchers at the University of Pennsylvania have developed an experimental treatment in which mutated HIV cells have been used to “reprogram” patients’ immune systems to be able to kill cells causing acute lymphoblastic leukemia, according to findings presented on Monday, December 10 at a meeting of the American Society of Hematology in Atlanta. The results represent the achievement of years of research into finding a means of enabling a cancer patient’s own immune system to permanently fight off the disease.

Under the treatment, millions of a patient’s T-cells (a form of white blood cell) are removed, and new genes are introduced that allow the T-cells to destroy cancer cells. The treatment utilizes a disabled form of HIV, based on the virus’ ability to introduce genetic material into T-cells.

The new genes reprogram the T-cells to fight off B-cells, which are part of the immune system that leukemia turns malignant. In successful cases, when the altered T-cells are reintroduced into the patient, they multiply and destroy the cancer cells.

Using the same technique, the study authors hope they can reprogram a patient’s immune system to treat prostate and breast cancer.

The researchers say their goal is for the new treatment to eventually replace bone-marrow transplantation, a difficult procedure which is the last option available for many living with leukemia and similar conditions.

Only a dozen patients with advanced leukemia have the received the experimental treatment. Besides the University of Pennsylvania, similar studies are in trials at Memorial Sloan-Kettering in New York City and the National Cancer Institute in Bethesda, Maryland.

In the University of Pennsylvania trials, three adults with chronic leukemia treated under the experimental protocols underwent full remissions, with no signs of disease; four adults improved but did not experience complete remissions, one of them being treated too recently to evaluate. Two adults experienced no results, one child improved and then relapsed, and one child has gone into full remission.