Genentech drug achieves breakthrough in breast cancer

The results published in The New England Journal of Medicine were described in the journal as “simply stunning” by Gabriel Hortobagyi of the University of Texas MD Anderson Cancer Center in Houston.

The analysis showed that the addition of Herceptin in chemotherapy achieved the reduction in recurrence of the disease in women with a type of cancer classified as early-stage, operable human epidermal growth factor receptor 2 (HER2)-positive breast cancer, compared to those patients who received chemotherapy alone.

HER2-positive breast cancer is an especially aggressive form of the disease that affects approximately 25 percent of women with breast cancer.

After four years of study follow-up, 15 percent of women treated with Herceptin plus chemotherapy experienced disease recurrence, compared to 33 percent of women treated with chemotherapy alone.

These data are from a planned interim analysis of more than 3,000 patients, and were first presented at the 41st Annual Meeting of the American Society of Clinical Oncology (ASCO) in May 2005.

“The results of these studies represent in quantitative terms the largest improvement in outcome for any group of women with breast cancer in 25 years,” said Dr Edward Romond, associate professor of medicine, Division of Hematology/Oncology at the University of Kentucky. “If these early findings continue to hold up, it may mean that the prognosis for women with one of the most worrisome types of breast cancer could change from poor to good.”

Although the results reported are extremely positive, there are concerns about the safety of the drug which has been shown to increase the risk of serious cardiovascular adverse events.

A survival analysis conducted after patients had been followed for a median of 24 months showed a 49% improvement in overall survival. Investigators continue follow-up of patients participating in the study and data continue to mature.