FDA Approves New Use for Breast Cancer Drug Herceptin

The U.S. Food and Drug Administration has approved a new use for the breast cancer drug Herceptin by women who are shown by a test to have HER2 gene amplification.

Herceptin is an antibody used to treat HER2-positive metastatic breast cancer. The drug is the preferred first-line therapy when given in combination with paclitaxel and is used alone for second- and third-line therapy.

The gene-detection test, made by Vysis PathVysion, is called FISH (fluorescence in situ hybridization) and identifies women with breast cancer who might benefit from Herceptin therapy. The FISH test measures the number of genes in each cell, using fluorescent dye so the HER2 genes can be seen and counted with a special microscope. More than the normal two HER2 genes per cell are present in HER2-positive breast cancer. Women with cancer cells containing too many copies of the HER2 gene (gene amplification) are candidates for treatment with Herceptin.

Herceptin's new label explains that patients in clinical trials whose tumors showed HER2 gene amplification benefited from treatment with the drug. Patients selected using FISH testing treated with Herceptin in addition to standard chemotherapy had a 30 percent decrease in the risk of death and a 56 percent decrease in the risk of breast cancer progression compared to women treated with chemotherapy alone.

"Herceptin is one of the first examples to demonstrate the benefits of a targeted medicine," said Dr. Gwen Fyfe, senior director of Oncology, Medical Affairs at Genentech. "In our pivotal trial Herceptin in combination with chemotherapy demonstrated an increased survival benefit compared to chemotherapy alone, demonstrating the importance of identifying appropriate candidates for Herceptin therapy."

Other sources: FDA, Genentech