Breast cancer can be a treatable disease, but only if diagnosed early. Since the prognosis grows considerably worse once the cancer has spread to other organs, the prevention of metastasis-the phenomenon in which cancer cells separate from a tumor mass, move through the bloodstream, anchor down in a distant tissue or organ to begin a new cancer-remains a critically important goal. The most recent figures from the Centers for Disease Control and Prevention indicate that more than 200,000 U.S. women are diagnosed with new cases of invasive breast cancer each year and that more than 40,000 of these women will die of the disease-usually the end result of metastasis.
The therapeutic use of monoclonal antibodies has expanded rapidly over the last several years precisely because of their long half-life, combined with their overall lack of toxicity and the fact that they can be easily designed and produced. For cancer treatment, the ability of antibodies to direct immune system responses to specific tumor types is one of the factors that have led to their increased use.
Until recently, it had been widely accepted that while antibodies possess a number of therapeutically advantageous traits, treatment with monoclonals required a different antibody for each specific target. However, the paper's authors have been showing that scientists can use different small molecule targeting agents-called programming agents or adapters-to selectively direct the same antibody to different sites for different uses so that only a single antibody is required for multiple tasks.
Recent research led by Scripps Research Professor Carlos F. Barbas III, for example, used the chemically programmed antibody approach in a melanoma model, dramatically enhancing the effectiveness of a small molecule drug (International Journal of Cancer 119 (5), 1194-1207, March 28, 2006).