Blood cells modified in the lab to kill Cancer

Chronic lymphocytic leukemia is a type of cancer of the blood and bone marrow that's "essentially incurable today," says Michel Sadelain, an immunologist at Memorial Sloan-Kettering who didn't work on the study. This year, an estimated 14,620 people will be diagnosed with CLL, and 4,650 people will die of the disease. Some patients can become disease-free thanks to stem cell transplant treatments, but these treatments are complicated and often don’t work, Sadelain says. So for the most part, common treatments like chemotherapy only serve to prolong a patient's life. That's why something like this blood cell-based treatment is such a big deal. The overall response rate in the study was 57 percent, a huge achievement for a form of cancer that used to kill most people in a median time of 8 to 12 years. The therapy works like this: first, doctors take a patient’s blood and spin out the T cells, white blood cells that hunt down invaders as part of the immune system. Then, in the lab, the T cells undergo gene therapy that trains them to hunt a protein expressed only on the surface of B cells, the type of blood cell that’s affected in leukemia. Then, the retrained cells are infused back into the patient’s bloodstream, where they hunt all B cells, even if they aren’t cancerous. People who respond to therapy have to live without a part of their immune systems; not ideal, but better than death.
"This is a whole new approach to treating cancer," says David Porter, a leukemia researcher at the University of Pennsylvania and a co-author of the study. By modifying T cells, scientists have found a way to harness the human immune system so it can hunt down and kill cancerous cells.