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Anastrozole Approved for the Adjuvant Treatment of Hormone Receptor-Positive Early Breast Cancer in Postmenopausal Women

September 19, 2005 - Wilmington, DE - AstraZeneca announced today that the U.S. Food and Drug Administration (FDA) has granted full approval status to Arimidex (anastrozole) for the adjuvant treatment of hormone receptor-positive early breast cancer (EBC) in postmenopausal women. Arimidex is the only aromatase inhibitor with study results representing a full five years of efficacy and safety data in this primary adjuvant setting, and is now the only aromatase inhibitor that has proven superior disease-free survival over tamoxifen in the primary adjuvant setting.

This long-term data for Arimidex provides clinicians and patients an opportunity to make the most informed decision about their primary adjuvant therapy. “We’re proud to provide doctors and patients with this critical, long-term information regarding Arimidex. The five-year profile of safety and efficacy is similar to that seen in the initial analysis with no new concerns arising from this mature data set,” said Joseph Purvis MD, Executive Director Medical Science at AstraZeneca. Arimidex is currently the most widely prescribed aromatase inhibitor for breast cancer patients.

In September 2002, the FDA approved a supplemental New Drug Application (sNDA) for Arimidex under the provisions for accelerated approval, with further follow-up required for full approval. The supplemental approval was based on recurrence-free survival data from the Arimidex Tamoxifen Alone or in Combination (ATAC) trial with a median duration treatment of 31 months.

Since that time, AstraZeneca has been dedicated to completing the commitments required by the FDA for full approval. Complete five-year data from the ATAC trial was published in December 2004 in the Lancet and was presented at the 2004 San Antonio Breast Cancer Symposium. The data indicated that Arimidex significantly reduced the relative risk of breast cancer recurrence by 17 % over tamoxifen in the clinically relevant hormone receptor-positive patients for whom Arimidex is indicated. This data was submitted to the FDA to satisfy the accelerated approval requirement for five years of follow-up on Arimidex use in early breast cancer.

The ATAC trial is one of the world’s largest breast cancer treatment studies. It also remains one of the longest running trials studying treatment after surgery for early breast cancer.

Arimidex and tamoxifen remain the only hormonal therapies approved by the FDA for the primary adjuvant treatment (treatment following surgery, with or without radiation) for hormone receptor-positive postmenopausal women with early breast cancer.

About Arimidex
Arimidex is indicated for adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer.

Important Safety Information About Arimidex
Arimidex should only be used in postmenopausal women. Arimidex can cause fetal harm when administered to a pregnant woman. Before starting treatment, pregnancy must be excluded (see WARNINGS in full prescribing information). The most common side effects seen with Arimidex versus tamoxifen in the early breast cancer clinical trial include hot flashes (36% vs 41%), joint disorders, including arthritis, arthrosis and arthralgia (36% vs 29%), weakness (19% vs 18%), mood changes (19% vs 18%), pain (17% vs 16 %), nausea and vomiting (13% vs 12%), sore throat (14% vs 14%), depression (13% vs 12%), hypertension (13% vs 11%), osteoporosis (11% vs 7%) and headache (10% vs 8%). Fractures, including spine, hip and wrist fractures, occurred more often with Arimidex than tamoxifen (10% vs 7%).

Tamoxifen should not be administered with Arimidex. Estrogen-containing therapies should not be used with Arimidex as they may diminish its pharmacologic action.

For further information about AstraZeneca and full Prescribing Information please visit or

Source: AstraZeneca

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