For Immediate Release
June 8, 2005

Dr. Ben Seon to Present Angiogenesis Study at Era of Hope Meeting

BUFFALO, NY – Ben Seon, PhD, Department of Immunology, Roswell Park Cancer Institute (RPCI), will present the results of a study titled, “Anti-Angiogenic and Vascular Targeting Therapy of Breast Cancer by Targeting Endoglin (CD105) of Tumor Vasculature,” at the Fourth Annual Era of Hope meeting for the Department of Defense Breast Cancer Research Program, June 8 – 11, Philadelphia, PA.

The study highlights efforts to develop a novel anti-angiogenic and vascular targeting agent to treat breast and other cancers. Growth of solid tumors requires angiogenesis – the formation of new blood vessels that provide the tumor with nutrients, oxygen and other factors. Anti-angiogenesis involves inhibition of formation of new blood vessels, whereas; vascular targeting therapy involves attacking the existing new blood vessels in tumors to cause tumor cell death.
To this objective, Dr. Seon has targeted endoglin (CD105) that was discovered at Roswell Park and the Hospital for Sick Children in Toronto, Canada.  Endoglin is a proliferation-associated cell membrane antigen of endothelial cells and leukemia cells that is strongly expressed in angiogenic blood vessels of human tumors. In addition, endoglin is essential for angiogenesis and is an ancillary receptor of transforming growth factor beta (TGF-ß).

In the current study, Dr. Seon generated 12 anti-endoglin monoclonal antibodies (mAbs) using an unconventional approach. Some of these mAbs (e.g., SN6f, SN6h and SN6j) were found to have unique properties that include definition of unique antigenic determinants and/or possession of an extremely high antigen-binding affinity. Importantly, these mAbs and/or their immunoconjugates showed both anti-angiogenic activity and vascular targeting activity in studies of several different animal models. 

In animal studies, systemic administration of select anti-endoglin mAbs or their immunoconjugates could suppress angiogenesis, tumor growth and metastasis without overt toxicity. In additional studies, combining anti-endoglin mAb with a chemotherapeutic drug (e.g., cyclophosphamide) showed that the drug strongly potentiated antitumor activity of the anti-endoglin mAb. Further, the test results suggest that these anti-endoglin mAbs will be more effective for cancer therapy in humans than in animal models.

“In additional studies, efforts have been directed to understanding the mechanisms by which unconjugated anti-endoglin mAbs suppress angiogenesis, metastasis and tumor growth,” according to Dr. Seon. “The next step will be to conduct phase I and II clinical trials of c-SN6j in breast cancer patients.”

The Era of Hope meeting provides a forum for scientists, physicians, breast cancer survivors and advocates, policymakers and the general public to learn about advances against breast cancer. The meeting highlights the multidisciplinary and innovative approaches funded by the Department of Defense (DOD) Breast Cancer Research Program in its effort to eradicate breast cancer.

Roswell Park Cancer Institute, founded in 1898, is the nation’s first cancer research, treatment and education center and is the only National Cancer Institute- designated comprehensive cancer center in Upstate New York.  RPCI is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation’s leading cancer centers.  For more information, visit the RPCI website at www.roswellpark.org, call 1-877-ASK-RPCI (1-877-275-7724) or e-mail askrpci@roswellpark.org.

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