Researchers test monoclonal antibody treatment for early stages of breast cancer

Tuesday, July 11, 2000

JACKSONVILLE, Fla., July 11, 2000 — Researchers at 200 medical institutions nationwide, including Mayo Clinics in Rochester, Minn.; Scottsdale, Ariz.; and Jacksonville, Fla., are studying a monoclonal antibody treatment for breast cancer in women with early stages of the disease. They hope this treatment will affect the cure rate, not just the length of survival from breast cancer.

About 30 percent of women with breast cancer have an aggressive form of the disease in which cancer cells produce an abundance of a growth-promoting protein called human epidermal growth factor receptor 2 (HER2). Previous studies in women whose cancer had spread beyond breast tissue showed that trastuzumab, a monoclonal antibody, slowed cancer cell growth and increased survival by binding to HER2. A monoclonal antibody is a laboratory-engineered protein that helps the body's immune system fight foreign invaders such as cancer.

Dr. Edith Perez, an oncologist at Mayo Clinic in Jacksonville, Fla., is the principal investigator of this new study. She designed the study to test the effectiveness of introducing trastuzumab, marketed as Herceptin, as an agent in adjuvant therapy for breast cancer. Doctors use adjuvant therapy to kill any cancer cells that might remain and to prevent their spread, after initial therapy used to kill or remove tumors.

"It's a novel therapy for breast cancer — very different than what we've had before," Perez says. "Now we have a monoclonal antibody treatment, which is a more specific therapy to target an abnormality of the tumor. It's what we've been hoping for all the time — that we find something that's different between the cancer cells and the normal cells and exploit it."

Perez and her coinvestigators are recruiting 3,000 women over the next four years for the study. Eligible women must have breast cancer detected in the lymph nodes and produce an overabundance of HER2. The women will be divided into three groups. One group will not get Herceptin. The second group will receive Herceptin after chemotherapy, and the third group will receive Herceptin along with chemotherapy.

Genentech, the company that developed and markets Herceptin, and the National Cancer Institute are sponsoring the study. "Trastuzumab has been shown to improve the efficacy of chemotherapy for patients with advanced breast cancer," says Perez. "So it's logical for us to move into the setting where it may have an impact on the cure rate of breast cancer."

Women interested in enrolling in the trial should talk with their physician.

An estimated 182,800 American women will be diagnosed with breast cancer this year. After skin cancer, breast cancer is the most common cancer in women and the second leading cause of cancer deaths in women.

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Media contact: Erik Kaldor 904-953-2299

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