If you’re a woman with HER2 positive breast cancer, stand up right now and cheer: Tykerb, a new drug approved this week by the FDA, has just doubled the arsenal of effective treatments.
Up till now, Herceptin has been the only somewhat effective treatment for HER-2 positive cancer, which affects one-third of women with invasive breast cancer.
Unfortunately, Herceptin doesn’t work for all women, and it also tends to lose its effectiveness over time. In addition, it’s been shown to cause heart damage in some women, a side effect thus far not seen with Tykerb.
Another plus: Tykerb, a product of pharmaceutical giant GlaxoSmithKline, is a simple once-a-day pill. Herceptin, administered by injection, requires a monthly trip to the hospital and a stay in the infusion area, never a happy experience.
Without getting too awfully clinical, the HER-2/neu protein forces cells to grow like crazy. When combined with other factors that cause cells to become invasive, you have a recipe for disaster: aggressive, fast-growing, invasive breast cancer.
Up till now, Herceptin has been the only treatment known for HER-2 positive cancers; it works as an antibody, binding to receptors on the outside of cells (much like tamoxifen does) to prevent them from growing. Tykerb goes Herceptin one better; it actually enters the cell to disable the protein from within.
In a major clinical trial held last year involving 321 HER-2 positive women with advanced breast cancer taking chemo, those who only got the chemo showed no cancer growth for 19.7 weeks; while those getting chemo and taking Tykerb as well showed no growth for 36.9 weeks, nearly twice as long. The drug’s clear success led researchers to put a quick end to the trial, allowing all the women involved to start taking Tykerb.
"The approval of Tykerb is a significant step forward because it once again demonstrates the promise of targeted therapies, where we take our understanding of how cancer cells work and apply that knowledge to new drug development,” said Dr. Len Lichtenfeld, 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. And we now have two drugs that are effective in treating this particular form of the disease.” Up to 10,000 women die of metastatic HER2-positive breast cancer each year.
Bottom line for the drug companies? Herceptin accounts for $3 billion/year in sales for Genentech and parent company Roche Holding AG. Tykerb is expected to generate $1 billion in sales by 2010 for GlaxoSmithKline. In addition, researchers say Tykerb shows promise for fighting other forms of breast cancer, and more broadly, other solid tumor cancers; its marketplace future looks extremely bright.
Bottom line for you? Tykerb will be available in the U.S. within 2 weeks, GlaxoSmithKline reports. Your future looks brighter now, too.