Phase II human trials may begin this summer.

ANN ARBOR, Mich.---Interleukin-2, a well-known weapon in the fight against cancer, has proven to be a powerful new addition to a University of Michigan cancer vaccine that mobilizes the body's own immune system to attack and destroy malignant cells.

In a study published in the March 2 issue of the Proceedings of the National Academy of Sciences, U-M researchers present the results of experiments testing the effectiveness of the vaccine/IL-2 combination on laboratory mice with large, advanced sarcomas or breast cancers. While not included in the PNAS article, U-M scientists also are studying other types of tumors, including aggressive skin cancers called melanomas, to determine their response to the vaccine/IL-2 combination.

It is the first study to combine interleukin-2, a growth factor that stimulates immune system cells to divide and multiply, with a cancer vaccine made from specialized white blood cells called dendritic cells, which alert the body's immune system to the presence of cancer.

"The addition of IL-2 substantially improved our vaccine's anti-tumor effect," said James J. Mulé, Ph.D., professor of surgery in the U-M Medical School, director of the Tumor Immunotherapy Program in the U-M Health System's Comprehensive Cancer Center and a member of the U-M Life Sciences Commission.

"Some mice with well-established, advanced lung and skin tumors showed no evidence of disease after treatment," Mulé said. "Others experienced substantial tumor regression and lived longer than mice treated with either the vaccine or IL-2 alone."

Based on these results, U-M researchers have requested approval to begin a Phase II trial of the cancer vaccine with IL-2 in adults with advanced metastatic melanoma.

Dendritic cells alert the immune system to cancer by presenting pieces of digested tumor proteins called antigens to white blood cells called T-lymphocytes. When the
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Contact: Sally Pobojewski
pobo@umich.edu
734-647-1844
University of Michigan
2-Mar-1999