Immunotherapy advance

Researchers from the National Institutes of Health are finding limited but inspiring success in a new approach for fighting cancer, using the immune system to attack the tumors the way it would a cold or flu.

The human immune system doesn't usually fight cancer on its own, so Dr. Steven Rosenberg and his NIH colleagues are trying to genetically engineer it, using a virus they created in the lab that seeks out cancer tumors and attaches to them.

Rosenberg's idea: Mix the cells that seek out the cancer with the immune cells that destroy things and see whether it would create a sort of smart bomb for the cancer.

In the study, Rosenberg tested the approach in 17 patients with advanced melanoma, a dangerous form of skin cancer. All the conventional treatments for the disease already had failed in all of the patients.

In 15 of the patients Rosenberg's engineered immune-cell treatment didn't work, but in two of the patients the cancer seems to have completely disappeared. The findings are published in this week's issue of the journal Science.

The finding has created excitement and hope among cancer experts. Dr. Philip Greenberg of the University of Washington School of Medicine called it "the beginning of a new chapter in treating cancer patients."

First the doctors removed white blood cells called lymphocytes from the patients; the cells are the warriors of the immune system. The lymphocytes were paired with the virus that doctors had genetically engineered in the lab to seek out cancer tumors and attach to them. The hope was that the super-immune cells would destroy the tumors.

Once the immune cells had been genetically engineered, patients underwent chemotherapy to kill most of their original immune cells. Then the new juiced-up cells were infused back into the body and the patients were given a treatment called Interleukin 2, which strengthens the new immune system.

When veterans in the field of cancer, who have had their hopes dashed many times, talk of a study being the beginning of a new chapter in cancer treatment, it draws attention.

The next step for Rosenberg is another clinical trial with potentially stronger gene therapy, and he expects to hear in the next few weeks whether the FDA has approved the trial. He acknowledges that much work lies ahead, but he believes that in the long run this approach will work on about half of all common cancers.