Trained immune system may help fight cancer--study

Scientists from Dana-Farber Cancer Institute, Boston, have revealed a novel technique by which the memory T-cells can be trained to attack tumors without the need of highly toxic treatments.

Previous treatment with programmed T-cells was unsuccessful as they could not remember to fight cancer for a longer period without the use of other treatments which often had severe side-effects.

The study, published in the journal ‘Science Translational Medicine,’ reported a phase-I study in which the scientists managed to keep the cells working in the patient’s bloodstream for more than a year.

Adoptive immunotherapy
Researchers tested the technique, a form of ‘adoptive immunotherapy’, in nine patients with advanced melanoma, a malignant tumor associated with skin cancer, which spreads from the skin to other parts of the body.

The technique involved removing specific T-cells from the patient’s blood, and exposing them to protein antigens found only in tumor cells, in the lab using genetic engineering to identify and kill tumor cells.

The treatment did not stop the advancement of the disease in the majority of subjects; however, one patient did show complete improvement with no signs of cancer after 25 months of the therapy.

Five of the patients with the injected trained T-cells, were given the drug ipilimumab to boost the cells’ anti-tumor response. Three of them showed a long-term shrinkage and two had their disease stabilized, neither advancing nor retreating.

Long-lasting immune system
"The study demonstrates it is possible to maintain high levels of anti-tumor T cells in patients over a long period of time while avoiding the complications of conventional approaches," said the study's lead author, Marcus Butler, MD, of Dana-Farber's Early Drug Development Center.

"Our technique opens the way to therapies that produce less-toxic, long-lasting immune system attacks on cancer cells."

"Our next step will be to study this technique in conjunction with other therapies that can boost the numbers and effectiveness of these memory T cells," said the study's senior author, Naoto Hirano, MD, PhD, of Dana-Farber and the Ontario Cancer Institute in Toronto.

"We will be beginning a series of clinical trials to learn which combinations work best in which patients," he said.