Patient's Own Cells Fight Melanoma

(Ivanhoe Newswire)-- Those suffering from Melanoma may have new hope. A recent study shows that a patient's own cells may reduce advanced melanoma and send the cancer into remission.

Cassian Yee, M.D., a member of the Clinical Research Division of Fred Hutchinson Cancer Research Center, had a goal to find the ideal cellular environment in which to infuse 15 billion to 20 billion cancer-fighting CD8+ T cells so that they remain for as long as possible in the body to battle the tumors. The cells, which were removed from the patients and multiplied in the lab before re-infusion, are a type of white blood cell that attacks a protein linked to the cancer.

All the participants in this study had progressive metastatic melanoma that was unresponsive to traditional therapy. Before the T-cell infusions, all were treated with high doses of cyclophosphamide to destroy their lymphocytes, a type of white blood cell that is part of the immune system. This was done to stimulate the production of certain growth factors that help promote additional production of the T cells within the body.

Eight of the 11 patients received low doses of interleukin-2 growth factor after the T cells were infused to further promote cell growth. Among these patients, one showed a complete remission and four patients, who had failed traditional therapy, experienced a temporary non-progression of their disease. The remaining three patients received higher doses of IL-2, which was found to be more harmful to the body. Two of these patients had temporary non-progression of their disease.

In all of the patients-except for the one who attained a complete remission-disease eventually progressed within 12 to 19 weeks of T-cell infusion.

Individual variations between patients with concern to how long the infused T cells persisted within the body probably explained why some responded to treatment better than others. "Certainly there are differences between patients but we think that persistence of the infused T cells in the body has a lot to do with it," Yee was quoted as saying. "It tells us we certainly have a way to go."

"Our results confirm that if we can develop methods to grow these kinds of cells in the lab, then we can give these high-proliferating, helper-independent T cells to all patients for T-cell therapy," Yee, who is a researcher in the Hutchinson Center's immunotherapy program, was quoted as saying. "Fortunately, we have been able to achieve this goal and are in the process of treating patients in an ongoing study with these helper-independent T cells."

Forthcoming studies may use different forms of interleukin growth factor and maybe even vaccines to boost the body's response to the infused cells, Yee said.

SOURCE: Proceedings of the National Academy of Sciences, March 2012.