'Arimidex' is the first and only aromatase inhibitor to be approved for use in the adjuvant treatment of early breast cancer in postmenopausal women. 'Arimidex' is already licensed worldwide for use in advanced disease where it has become the world's leading aromatase inhibitor with over 600,000 patient years experience.

"Since first seeing the strength of the ATAC results, we have worked quickly to seek extended licenses for 'Arimidex', and bring the proven benefits of the drug to the many postmenopausal women newly diagnosed with early stage breast cancer," said Bernie Tyrrell, Vice President, Marketing, AstraZeneca Oncology. "We believe that the results of the ATAC study are truly groundbreaking for the management of this devastating disease, and we look forward to further license approvals in other markets in the future."

'Arimidex' has already been approved as an adjuvant treatment for postmenopausal women with early breast cancer in Belgium and Mexico and, additionally, AstraZeneca has a licence to promote this indication in Japan. AstraZeneca submitted data packages requesting approval for 'Arimidex' in early breast cancer in Europe and in other rest of world markets earlier this year. 'Arimidex' sales in 2001 were $191 million, a 22 percent increase over the previous year. AstraZeneca's Nolvadex® (tamoxifen) accounted for $630 million in sales the same year. The early breast cancer market could be worth approximately $2 billion.

Study Results

The ATAC study - which is now published as a peer-reviewed paper in The Lancet - demonstrated that 'Arimidex' is more effective than tamoxifen in terms of disease free survival. The findings represent a 17 per cent relative risk reduction for breast cancer recurrence with 'Arimidex' treatment compared to tamoxifen. Among women confirmed with hormone-sensitive tumours, the reduction in relative risk with 'Arimidex' compared with tamoxifen was even more striking, at 22 per cent.

Additionally, 'Arimidex' shows an important benefit in reducing the likelihood of the cancer spreading to the opposite breast ('contralateral' breast cancer). Compared with tamoxifen (which had already shown an almost 50 per cent reduction in this area versus control), 'Arimidex' reduces the risk by a further 58 per cent.

'Arimidex' was also found to have many important tolerability advantages over tamoxifen. The published results are from the first planned analysis of the ATAC data at a median duration of 33.3 months follow-up. Additional follow-up for safety and efficacy is protocolled in the trial.

AstraZeneca (NYSE:AZN) 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 over $16.4 billion and leading positions in sales of gastrointestinal, oncology, anesthesia (including pain management), cardiovascular, central nervous system (CNS) and respiratory products.