Study seeks women with recurring disease to test new antibody.

2003 AUG 7 - (NewsRx.com & NewsRx.net) -- The University of California, Los Angeles, Jonsson Cancer Center is testing an experimental immune system-boosting antibody that could one day help women who have not responded to conventional chemotherapy treatments for metastatic breast cancer.

The Phase I study uses an antibody directed at the MUC1 protein, which is exposed on the surface of cancer cells in more than 90% of women who have breast cancer. In normal tissues, MUC1 is a protein that is literally sugar-coated, being completely surrounded by carbohydrate molecules. In rapidly growing cancer cells, the sugar structures do not form correctly and the protein core of MUC1 is exposed. Researchers believe this exposed protein core can become a new target that is vulnerable to attack by antibodies.

In laboratory studies, the antibody called R1550 (formerly Therex) has been shown to bind tightly to MUC1 on cancer cells and then activate immune system cells to kill the cancer. Using antibodies to encourage the body's own immune system to do its job is a different way of fighting cancer. Other targeted therapies help cancer-killing drugs work better, but this study seeks to engage the natural immune system cells to do the killing.

"Our study is a real test of an antibody as immunotherapy ...