An experimental vaccine technique using a patient's own cells to enhance the body's immune response may represent the future of cancer treatment.

In a pair of studies, researchers leveraged dendritic immune system cells found in the skin to boost immune response to melanoma in patients. Investigators from the Washington University School of Medicine in St. Louis reported Thursday the effectiveness of such a vaccine against advanced melanoma, as six of seven patients with stage IV disease experienced a response to the vaccine, while the progression of tumor growth slowed in three of them.

The researchers modified the dendritic cells to increase production of a molecule called interleukin 12p70, which stimulates a strong response to the cancer.

"This is personalized immunotherapy," senior researcher Gerald Linette, an associate professor of medicine and neurosurgery, told reporters. "The results show that, in fact, interleukin 12p70 was very important in controlling the disease," he said. "It promoted a response where T cells of the immune system act directly against the melanoma."

However, the production of the molecule varies by patient, with some making little or no interleukin 12p70. Linette said other ways of enhancing the response would have to be tried to help those patients.

Less than two weeks ago, investigators from Duke University Medical Center reported similar news of a vaccine in a phase I clinical trial using dendritic skin cells to stimulate antigen-specific T cells in a dozen study subjects with metastatic melanomas. The immune response peaked after 3-4 vaccinations but remained elevated as levels of melanoma cells fell and T cell activity rose.

Of that group, 11 remained alive after 35 weeks of follow-up and six were free of any signs of the disease.

The deadliest of skin cancers, melanoma kills more than 10,000 Americans every year, of a total of more than 76,000 cases, according to the U.S. National Cancer Institute.

Source: Dannull, Jens, Haley, Rebecca N., Archer, Gary, Nair, Smita, Boczkowski, David, Harper, Mark, et al. Melanoma Immunotherapy Using Mature DCs Expressing The Constitutive Proteasome. Journal of Clinical Investigation. 2013.