The team of scientists who discovered that angiostatin could dramatically boost the effects of radiation therapy has now shown that only brief exposure to angiostatin is required to get most of the drug's radiation-boosting anti-tumor effects. Without concomitant radiation therapy, additional exposure to low doses of this highly touted, costly and hard-to-obtain protein did not enhance treatment.

This latest report, by researchers from the University of Chicago Medical Center, Harvard Medical School and Northwestern University in the December 15 issue of Cancer Research, adds to the mounting enthusiasm about combining angiostatin with other forms of cancer therapy.

"The limited angiostatin supplies may be most effectively and efficiently used in combination with cytotoxic therapies such as ionizing radiation," note the authors. "These results suggest a new approach to the design of clinical trials with angiostatin and other anti-angiogenic agents."

The research team, led by Ralph Weichselbaum, M.D., professor and chairman of radiation oncology at the University of Chicago, tested the anti-tumor effects of angiostatin and radiation alone and in various combinations. They used large (500mm3), rapidly growing human tumors transplanted into mice.

As expected, the most effective therapy was the combination of simultaneous angiostatin and radiation therapy. What was not anticipated was how little angiostatin was required to make a big difference, or how limited the benefits would be from continuing to give low-dose angiostatin after completing a short course of radiation.

The study wasn't designed to assess the effects of angiostatin, used here in very small doses, but to determine t
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Contact: John Easton
jeaston@mcis.bsd.uchicago.edu
773-702-6241
University of Chicago Medical Center
15-Dec-1998