What is FASLODEX?

FASLODEX, a type of hormonal treatment known as an antiestrogen, is for hormone receptor-positive metastatic breast cancer in postmenopausal women whose breast cancer has recurred or progressed following antiestrogen therapy, such as tamoxifen. FASLODEX is a hormonal treatment, not a cytotoxic chemotherapy.

Hormones, such as estrogen and progesterone, are naturally produced by organs in your body. Some breast cancer tumors need estrogen and/or progesterone to grow. These tumors are called hormone receptor positive.

This means that they have receptors for the hormones estrogen and/or progesterone. Hormone receptors are very small parts of a cell. If estrogen is present, it will attach to estrogen receptors, possibly making the tumor grow larger.

About two thirds of women with breast cancer have tumors that contain estrogen receptors.

FASLODEX works by binding to these estrogen receptors, which blocks estrogen from binding. FASLODEX also causes the estrogen receptor to change shape and not work as well. In addition, FASLODEX causes a decrease (downregulation) in the number of estrogen receptors. This may interfere with cancer cell activity, which, in part, may slow the growth of the breast cancer. See how FASLODEX works.

In clinical trials, FASLODEX was found to be effective in women whose breast cancer recurred or progressed following other antiestrogen therapy such as tamoxifen. FASLODEX is given by intramuscular (IM) injection once a month.