According to the FDA decision, announced yesterday, Herceptin may now be used in combination with other cancer drugs to treat HER2 positive breast cancer after surgery - either lumpectomy, which saves as much of the breast as possible, or mastectomy, in which the breast is removed.
The new approval expands Herceptin's use to women with cancer only in the breast or lymph nodes which have been removed with surgery.
The new FDA approval came after a fast-track review.
Herceptin targets the HER2 protein on cancer cells. When too much HER2 protein is present, cancer cells grow faster and standard chemotherapy may be less effective.
The drug is given intravenously.
It should only be prescribed for women diagnosed with HER2 positive breast cancer, states the FDA.
FDA: 'Good News'
"This is especially good news for women who have breast cancer caused by excessive amounts of the HER-2 protein because this cancer typically has a poor prognosis," says Steven Galson, MD, MPH, in an FDA news release.
Galson directs the FDA's Center for Drug Evaluation and Research.
The FDA based its decision on two studies sponsored by the National Cancer Institute (NCI), which is part of the National Institutes of Health, near Washington, D.C.
Patients in both trials received standard chemotherapy after surgery for breast cancer; approximately half the patients were also given Herceptin.
The results from both trials, which included information on nearly 4,000 women, were combined and analyzed in 2005. Due to the positive results, the NCI ended the studies early.
Positive Test Results
The women who received Herceptin combined with chemotherapy had fewer relapses (return of breast cancer) for up to three years after surgery.
The estimated three-year disease-free rates were 87% in women receiving Herceptin and chemotherapy, vs. 75% in those receiving chemotherapy alone, according to the FDA.
It is too soon to know whether Herceptin combined with chemotherapy will increase the cure rate or lower the risk of death from breast cancer, the FDA notes.
There are an estimated 212, 920 new cases of breast cancer and about 40,970 related deaths each year in the U.S.
Approximately 25% of women with breast cancer will have tumors that produce excessive amounts of HER2 protein, says the FDA.
The most serious side effect of Herceptin is heart failure -- a weakening of the heart muscle -- that requires medical treatment.
Because of the risk of heart disease, only certain patients should receive the drug, including:
- Only Patients whose tumors are HER2 positive.
- Patients who do not have heart failure or weak heart muscle (cardiomyopathy).
Patients must be screened for heart function before and during Herceptin treatment.
Less common but serious side effects include infusion reactions (chills, fever, shortness of breath) that rarely are accompanied by lung problems, low white blood cell counts, and low red blood cell counts.
Herceptin (trastuzumab) is made by Genentech. Genentech is a WebMD sponsor.