Study Shows Femara May be Better Than Tamoxifen for Advanced Breast Cancer (dateline September 24, 2003)
A newly published study shows that the drug Femara (generic name, letrozole) may be more effective at treating women with advanced breast cancer than the current standard, tamoxifen. In early 2001, the U.S. Food and Drug Administration (FDA) approved the drug Femara as an initial treatment option ("first-line therapy") for women with advanced breast cancer. The current study found that Femara slowed the progression of breast cancer and offered early, improved chances of survival. This provides further hope that Femara may be a viable option for women with advanced breast cancer.
Femara belongs to a class of drugs called aromatase inhibitors and works differently than tamoxifen. To grow and reproduce, breast cancer cells require the female hormone estrogen. Tamoxifen is an anti-estrogen and works by blocking estrogen from breast cancer cells, thereby "starving" cancer cells. In contrast, Femara works by reducing the total amount of estrogen in the body (circulating estrogen levels), thereby limiting the amount of estrogen that can affect breast cancer cells. Other examples of aromatase inhibitors include Arimidex (generic name, anastrozole) and Aromasin (generic name, exemestane). Both of these drugs are also used to help treat advanced breast cancer in women whose breast cancer tumors have not responded well to tamoxifen.
In the current study, researcher Henning Mouridsen of the Rigshospitalet in Copenhagen, Denmark and colleagues compared Femara to the standard breast cancer drug, tamoxifen, in 907 postmenopausal women with advanced breast cancer. Research was supported by a grant from Novartis Pharma AG, the maker of Femara.
The results showed that after an average of 32 months of follow-up, 48% of the patients who received Femara were able to prevent a progression of their cancers, compared with 27% of the women who received tamoxifen. Furthermore, patients treated with Femara were able to prolong the time before they needed chemotherapy from nine months (on tamoxifen) to 16 months (with Femara).
The following side effects were noted in the study:
(Femara versus tamoxifen)
Previous research has also shown that Femara may be more effective than tamoxifen at treating advanced breast cancer. In a study presented at the Chemotherapy Foundation Symposium XVIII in New York in November 2000, 900 women with advanced breast cancer received either Femara or tamoxifen. After one year of treatment, the number of women whose cancer had not progressed was nearly 50% greater among those who took Femara, compared with the women who took tamoxifen.
"FDA approval of this new indication means that thousands of post-menopausal women with advanced breast cancer will have a more effective hormonal treatment option," said David Parkinson, MD, Vice President of Clinical Research at Novartis Oncology in a Norvartis media release at the time of the drugs FDA approval. Femara is also approved to help treat women who do not respond well to tamoxifen or become resistant to it.