Friday, August 12, 2011

'Huge' Results Raise Hope for Cancer Breakthrough

by Eryn Brown, LA Times

In a potential breakthrough in cancer research, scientists at the University of Pennsylvania have genetically engineered patients' T cells — a type of white blood cell — to attack cancer cells in advanced cases of a common type of leukemia.

Two of the three patients who received doses of the designer T cells in a clinical trial have remained cancer-free for more than a year, the researchers said.

Experts not connected with the trial said the feat was important because it suggested that T cells could be tweaked to kill a range of cancers, including ones of the blood, breast and colon.

"This is a huge accomplishment — huge," said Dr. Lee M. Nadler, dean for clinical and translational research at Harvard Medical School, who discovered the molecule on cancer cells that the Pennsylvania team's engineered T cells target.

Findings of the trial were reported Wednesday in two journals.

To build the cancer-attacking cells, the researchers modified a virus to carry instructions for making a molecule that binds with leukemia cells and directs T cells to kill them. Then they drew blood from three patients who suffered from chronic lymphocytic leukemia and infected their T cells with the virus.

When they infused the blood back into the patients, the engineered T cells successfully eradicated cancer cells, multiplied to more than 1,000 times in number and survived for months. They even produced dormant "memory" T cells that might spring back to life if the cancer was to return.

"We knew [the therapy] could be very potent," said Dr. David Porter, director of the blood and marrow transplantation program at the Hospital of the University of Pennsylvania in Philadelphia and a coauthor of both papers, which were published in the New England Journal of Medicine and Science Translational Medicine. "But I don't think we expected it to be this dramatic on this go-around."

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