The U.S. Food and Drug Administration (FDA) has approved the combination of the targeted therapy Tykerb (chemical name: lapatinib) and the hormonal therapy Femara (chemical name: letrozole) to treat postmenopausal women diagnosed with hormone-receptor-positive, HER2-positive advanced-stage breast cancer.
The approval was based on research showing that women who received the combination lived more than twice as long as women who received only Femara.
Tykerb in combination with the chemotherapy Xeloda (chemical name: capecitabine) already is approved by the FDA to treat HER2-positive, metastatic breast cancers that have stopped responding to certain chemotherapy medicines and Herceptin (chemical name: trastuzumab). Herceptin is another targeted therapy used to treat both early-stage and advanced-stage HER2-positive breast cancers.
HER2-positive cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that encourage the cancer to grow and spread. About one out of every four breast cancers is HER2-positive. Tykerb works by blocking the HER2 protein's ability to make HER2-positive breast cancers grow.
Femara is an aromatase inhibitor, a type of hormonal therapy medicine, already approved to treat postmenopausal women:
- diagnosed with hormone-receptor-positive, early-stage breast cancer right after surgery and other treatments to reduce the risk of the cancer coming back
- diagnosed with hormone-receptor-positive, early-stage breast cancer who have taken 5 years of tamoxifen to reduce the risk of the cancer coming back
- diagnosed with advanced-stage or metastatic hormone-receptor-positive breast cancer
Femara works by blocking the body's ability to make the hormone estrogen. Arimidex (chemical name: anastrozole) and Aromasin (chemical name: exemestane) are other aromatase inhibitors used to treat both early-stage and advanced-stage hormone-receptor-positive breast cancer. Tamoxifen is another type of hormonal therapy used to treat both early-stage and advanced-stage, hormone-receptor-positive breast cancer. Tamoxifen works by blocking the effect of estrogen on breast cancer cells. Faslodex (chemical name: fulvestrant) also is a hormonal therapy used to treat advanced hormone receptor positive breast cancer. Tamoxifen and Faslodex work by blocking the effect of estrogen on breast cancer cells.
Tykerb is a pill taken by mouth. The most common side effects of Tykerb are diarrhea, redness and tingling in the hands and feet, and a rash. These side effects usually aren't severe. Other side effects can include stomach upset, vomiting, and fatigue. In rare cases, Tykerb can cause serious heart, lung, and liver problems.
Femara also is a pill taken by mouth. The most common side effects of Femara (and the other aromatase inhibitors) are muscle and joint pain and hot flashes.
If you're being treated for hormone-receptor-positive, HER2-positive advanced-stage breast cancer, hormonal therapy medicines and Herceptin and Tykerb are treatment options you and your doctor are probably considering. Based on the new FDA approval, a combination of Tykerb and Femara may be an option for you, depending on your previous treatment history and your unique situation.