New Use for Breast Cancer Drug OK'd

Dec. 29, 2005 -- The FDA has approved a new use for the breast cancer drug Femara.

Femara may now be taken by postmenopausal women with early, hormone-sensitive breast cancer immediately after surgery.

Femara had previously been an option for postmenopausal women with hormone-sensitive breast cancer who had already taken another breast cancer drug, tamoxifen.

Novartis -- the maker of Femara -- says Femara has already been approved for the same use in the U.K. and expects additional approvals in other countries in 2006.

Key Study

According to an FDA announcement, Femara's effectiveness in treating early breast cancer is based on an analysis of disease-free survival in patients who were treated and followed for an average of two years.

"Follow-up analyses will determine long-term outcomes for both safety and efficacy," states the FDA.

A news release from Novartis adds more details. Novartis states that the approval was based on results of a large, international study published in The New England Journal of Medicine.

In that study, postmenopausal women with hormone-sensitive early breast cancer were less likely to get breast cancer again if they took Femara instead of another breast cancer drug, tamoxifen, which also helped prevent breast cancer's return.

Targeting Estrogen

Femara and tamoxifen both target the female sex hormone, estrogen, which fuels some (but not all) breast cancers. But the two drugs work differently.

Tamoxifen, an older drug, has long been a cornerstone of breast cancer treatment. It blocks estrogen from binding onto cells.

Femara belongs to a newer (and more costly) family of drugs called aromatase inhibitors. Aromatase inhibitors target estrogen production, curbing the hormone's supply.

Aromatase inhibitors can raise a woman's risk of developing osteoporosis (thinning bones). In the Femara-tamoxifen study published in The New England Journal of Medicine, women taking Femara were more likely to fracture a bone than those taking tamoxifen.