AstraZeneca, a major international healthcare business engaged in the research, development, manufacture and marketing of ethical (prescription) pharmaceuticals and the supply of healthcare services, reported that the U.S. Food and Drug Administration (FDA) has granted marketing approval for its new breast cancer drug 'Faslodex' for the treatment of hormone receptor positive metastatic breast cancer in postmenopausal women with disease progression following antioestrogen therapy, (e.g. tamoxifen).

'Faslodex' is an antioestrogen (oestrogen receptor antagonist) without known agonist effects. Unlike aromatatase inhibitors that reduce the amount of oestrogen in a woman's body, and tamoxifen, which blocks the oestrogen receptor, 'Faslodex' targets and degrades the oestrogen receptors in breast cancer cells. It is the only antioestrogen in general clinical use to have demonstrated efficacy following tamoxifen failure, indicating that it works in a different way to tamoxifen. 'Faslodex' therefore represents another approach to treating hormone sensitive breast cancer.

"Advanced breast cancer treatment has significantly improved through sequential treatment with different and novel hormonal therapies. The introduction of 'Faslodex' expands that sequence, providing women with another treatment option that works in an uniquely different way," said Dr. George Blackledge, VP, medical director of oncology for AstraZeneca.

The breast cancer market in the USA is currently worth over $1 billion. An estimated 203,500 new cases of invasive breast cancer will be diagnosed in the USA and an estimated 39,600 women will die of breast cancer in 2002. A portion of newly diagnosed breast cancer cases will be initially diagnosed in the advanced or locally advanced stages where cancer has spread to the lymph nodes and/or other parts of the body.

Two pivotal Phase III trials showed 'Faslodex' to be at least as effective as the aromatase inhibitor 'Arimidex' in treating tamoxifen-resistant breast cancer in postmenopausal women. The new treatment is given as a once a month intramuscular injection, which may offer compliance benefits and, as an endocrine treatment, 'Faslodex' does not cause the side effects commonly associated with chemotherapy.

Dr. C. Kent Osborne, the lead 'Faslodex' trial investigator from Baylor College of Medicine, Houston, Texas, said, " 'Faslodex' provides an effective, new treatment option for women with advanced breast cancer whose tumours have become resistant to tamoxifen. When you have a new drug like 'Faslodex' that we can now add to that sequence of drugs, we may be able to control the breast cancer for a longer period of time".