Faslodex™ is characterised as an Estrogen Receptor Downregulator and works differently from other hormonal breast cancer drugs in that it targets and degrades the estrogen receptor. Currently, advanced breast cancer patients whose tumours have been shown to use hormones to grow, are given drugs like tamoxifen that act by blocking the estrogen receptor, or aromatase inhibitors that lessen the amount of estrogen in a woman’s body. After a period of time, tumours can become resistant to these types of treatments and cancer may progress. Faslodex™ represents a new way to attack cancer cells that have grown resistant to current hormonal treatment options.

The FDA submission was based on data from two phase III trials which compared Faslodex™ to Arimidex®, the most widely prescribed aromatase inhibitor, in measures of time to progression and response rate. All women in the trial were postmenopausal and had been treated with prior hormonal therapy, in most cases tamoxifen, and were randomised after their disease no longer responded.

In both the North American Trial and the European Trial, the time to progression and objective response rate were similar for Faslodex™ and Arimidex®. In the North American Trial the median duration of response was 19.3 months with Faslodex™ and 10.5 months with Arimidex®. In the European Trial, the duration of response for Faslodex™ and Arimidex® were similar. Faslodex™ is administered as a monthly intramuscular injection.

"Sequential treatment of advanced breast cancer with different hormonal therapies is significantly improving the way advanced breast cancer is treated today. If approved, Faslodex™ will offer an additional treatment option that works differently than currently available therapy," said Dr. Gerard Kennealey, Vice President of Medical Oncology for AstraZeneca.

AstraZeneca is committed to continued research on Faslodex™ and is currently evaluating it in a head-to-head trial with tamoxifen for first line advanced breast cancer. Results are expected early next year. Additional trials are in the planning stages for early breast cancer and for breast cancer in pre-menopausal women.

AstraZeneca is a major international healthcare business engaged in the research, development, manufacture and marketing of ethical (prescription) pharmaceuticals and the supply of healthcare services. It is one of the top five pharmaceutical companies in the world with healthcare sales of $15.8 billion and leading positions in sales of gastrointestinal, oncology, anaesthesia (including pain management), cardiovascular, central nervous system (CNS) and respiratory products.