Endocrine Breast Diseases clinical trials

Letrozole and Lapatinib Followed by Everolimus in Women With Advanced Breast Cancer

About a third of patients with breast cancer are usually treated by hormone pills called tamoxifen and aromatase inhibitors. Aromatase inhibitors are drugs that stop female hormone production. Female hormone or estrogen is an important hormone for the growth of breast cancer cells. Letrozole is one of the aromatase inhibitors that is approved by the FDA and has been used to treat breast cancer since 1997. However, hormone pills usually work for about 6-10 months in most patients. Later on, breast cancer will start to grow again. This condition when hormone pills or endocrine therapy no longer work is called "endocrine resistant" breast cancer. The scientists here at University of Maryland have discovered how these cancer cells can become resistant to hormone pills. In our laboratory tests, the investigators found that lapatinib and everolimus can reverse this resistance and make letrozole work again. However, it is not known if the drugs can reverse the resistance in humans. The purpose of this study is to find out whether the combination of letrozole, lapatinib, and everolimus is effective in women with breast cancer when hormone pills no longer work. Lapatinib is an anti-cancer drug that is already approved by the Food and Drug Administration (FDA). It is the standard of care for the treatment of a particular type of breast cancer called human epithelial growth factor receptor 2 (HER2)-positive breast cancer. HER2 is a protein involved in the growth of some cancer cells. This study will also include patients with HER2-negative breast cancer. This means that the cancer cells in these patients do not depend on the HER2 protein. The use of lapatinib in these patients is considered experimental. Everolimus is also an anti-cancer drug that is approved by the FDA for kidney cancer. Initial studies in mice and later studies in women with breast cancer have shown that everolimus may also slow the growth of breast cancer. The use of everolimus is experimental in this study.