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.
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
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.