14 DAY TRIAL // The targeted drug trastuzumab, or Herceptin, previously shown to prolong survival in advanced breast cancer, dramatically reduced the chances of recurrence in patients with early-stage disease when given for one year following standard chemotherapy.
These are the encouraging findings in an interim report from HERA, an ongoing large, international clinical trial of Herceptin, being published today in the New England Journal of Medicine. The analysis was led by Richard Gelber, PhD, of Dana-Farber Cancer Institute, who led the statistical analysis for the HERA trial, which is one of the largest breast cancer trials to date. It includes more than 5,000 patients in 39 countries.
Women whose tumors were HER2-positive, that is, overexpressing a protein associated with more aggressive cancer and poorer outcomes, had approximately a 50 percent lower risk of disease recurrence. This translated into an 8 percent improvement in the number of women who were free of disease two years after beginning the treatment.
"This is probably the biggest evidence of a treatment effect I've ever seen in oncology," says Gelber. "It is quite remarkable." Harold Burstein, MD, PhD, of Dana-Farber, wrote in a commentary published with the report that the results have "a profound lesson: not all breast cancers are the same." The study shows the success of therapy tailored to a specific biological form of the disease."Now we have made dramatic progress for patients with HER2-positive breast tumors, who now have a much lower risk of recurrence and better chance of survival because of trastuzumab," says Burstein.
Herceptin is a monoclonal antibody-based drug developed specifically to block the activity of the HER2 protein, a growth factor receptor that is overexpressed on cancer cells of an estimated 20 to 30 percent of breast cancer patients. HER2-positive tumors, which can be identified with a test when the breast cancer diagnosis is made, are generally more aggressive and prone to spreading, and are resistant to many chemotherapy agents.