Women with a particularly aggressive form of breast cancer now have a new option when other therapies have failed. The US Food and Drug Administration on Tuesday approved the drug Tykerb (lapatinib) for women with HER2-positive tumors that have continued growing despite treatment with chemotherapy and Herceptin (trastuzumab).
Tykerb comes in pill form and must be used in combination with Xeloda (capecitabine), a chemotherapy pill. In a clinical trial of nearly 400 women, this combo helped lengthen the time it took for breast cancer to start growing again compared to Xeloda alone (27 weeks vs. 19 weeks).
It is not known if Tykerb helps women live longer.
Having an extra option is important for women with this form of breast cancer, said Len Lichtenfeld, MD, deputy chief medical officer of the American Cancer Society.
"We now have a new drug that offers promise and hope to women who have a more aggressive form of breast cancer where until very recently, we had little to offer," he said.
Tykerb is a targeted therapy that blocks the HER2 protein that sits on the surface of breast cancer cells. It works in a slightly different manner than Herceptin, which also targets HER2. About 20% of women with breast cancer in the US have too much HER2 in their tumors.
The most common side effects of Tykerb include diarrhea, nausea, vomiting, rash, and hand-foot syndrome, a condition that causes numbness, tingling, redness, and discomfort in the hands and feet. A few patients in the clinical trial experienced declines in heart function; the FDA said patients should talk with their doctors about potential heart problems.
Tykerb is made by GlaxoSmithKline. The company has set up a program called Tykerb CARES (available at 1-866-489-5372) to help women get information about the drug, including help with insurance coverage and financial assistance.
