New cancer treatment reprograms immune system

A small medical study out today is generating a huge amount of excitement among cancer researchers. 

For the first time, scientists have been able to successfully target cancer cells by using cells from a patient's own immune system.

CBS news medical correspondent Dr. Jon LaPook reports that that the small study produced what researchers call "proof of concept." 

It's a whole new way, of treating cancer.

Researchers engineered a patient's own immune cells to treat a type of blood cancer called chronic lymphocytic leukemia, or CLL.

CLL affects nearly 15,000 men and women a year and more than 4,000 will die from it.

For years, researchers have been trying to figure out a way to kill cancer cells using a patient's own immune system. 

On Wednesday, Dr. Carl June and his team at the University of Pennsylvania School of Medicine claimed a victory in that effort.

"This is a form of what I would call ultimate personal therapy. 

That's a wave of the future," June says.

CLL is a type of blood cancer. 

The only known cure is a bone marrow transplant, which is risky, and only effective in about half of patients.

In this new approach, scientists used the patient's own T-cells - white blood cells that help fight infections such as bacteria. 

Scientists remove the T-cells, genetically reprogram them to attack leukemia cells, and inject them back into the patient.

Researchers treated three patients with CLL. In two, the cancer cells were completely gone six months after the immune therapy.

"The clinical doctor involved in this was astonished and so were the patients that a single infusion of the cells could have such pronounced anti-tumor effects in the patients," Dr. June says.

This new treatment does have significant side-effects. 

The most common is a very bad flu-like illness, but so far all 3 patients who had incurable leukemia and no other options are doing well about a year after treatment.

This form of treatment is like giving a scent to a bloodhound. 

These T-cells have been given the scent of the leukemia cells and go hunt them down. 

The hope is to give T-cells the scent of colon cancer, breast cancer, lung cancer and train them go out and kill all kinds of cancers.