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Anastrozole Label Indication Expanded in the UK

LONDON, June 28/PRNewswire/ -- From today, more postmenopausal women diagnosed with hormone-receptor positive breast cancer in the UK now have the opportunity to benefit from Arimidex (anastrozole) which offers a 26% reduction in the risk of breast cancer coming back compared with tamoxifen,[1] the gold standard for breast cancer management of 30 years standing. Today, AstraZeneca announced that the drug had been granted an indication, meaning that more postmenopausal women whose breast cancer is fuelled by oestrogen - about 75 per cent of all postmenopausal breast cancer cases[2] - are now eligible to receive Arimidex after surgery to prevent their disease returning.

"This is the moment we have been waiting for," said Mr Rob Carpenter, Consultant Surgical Oncologist at St Bartholomew's Hospital, London. "It has recently been confirmed that Arimidex offers crucial advantages over tamoxifen, in terms of enabling patients to stay disease free for longer. However, it is only now, with the new indication, that more postmenopausal women with breast cancer may benefit from this drug at the earliest opportunity after breast surgery. This news marks the beginning of a whole new era in breast cancer management."

The indication was granted by the Medicines and Healthcare products Regulatory Agency (MHRA) today on the basis of data from the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial, the largest breast cancer trial ever conducted. These data demonstrate that Arimidex reduces the risk of breast cancer recurring anywhere in the body by an additional 26% (HR =0.74; p= Success in the two-year window of risk
A new analysis from the ATAC trial, presented at the American Society of Clinical Oncologists in May 2005, demonstrated that the risk of breast cancer recurrence reaches a peak in the first two years after a patient receives surgery.[3] This supports previous research clearly demonstrating the peak in the risk of recurrence in the first two to three years.[4],[5]

Women treated with Arimidex immediately after surgery saw a reduced risk of recurrence in the first 18-24 months at a time when recurrences are at their highest level. The study authors concluded that this benefit in the first two years of treatment would be lost if patients did not start with an aromatase inhibitor immediately post-surgery.

Arimidex has also been shown to have a favourable side effect profile versus tamoxifen,[1] both in terms of serious life threatening side effects such as blood clots, stroke and cancer of the womb lining as well as symptoms that are important to women, such as hot flushes and vaginal discharge. However, women taking Arimidex experienced an increased risk of joint pain and fracture,[1] although fracture rates reported in the ATAC trial are similar to those seen in age-matched postmenopausal women. It is not known whether the fracture rates seen are due to a protective effect of tamoxifen, a specific effect of Arimidex or both.[6]

"This is exciting news for the 33,000 postmenopausal women diagnosed with breast cancer every year in the UK," commented Emma Pennery, Nurse Specialist and Consultant, Breast Cancer Care. "More patients eligible for hormone therapy will now have the opportunity to benefit from this more effective treatment option. At this pivotal moment in the way we treat breast cancer, it is crucial that women are fully informed and confident in discussing their treatment options with their specialists, to ensure that they are getting the best treatment to meet their needs at the earliest opportunity."

Breast cancer patient, Anne Hamer concurred. Having completed two years of treatment with Arimidex, she is confident of its benefits: "I am delighted that other breast cancer patients will now be able to benefit as I have from this treatment," she said. "For me, Arimidex has meant that I can get on with my life without letting cancer stand in the way. Knowing that I'm receiving the best treatment for me has given me peace of mind and confidence, but I know I was lucky to receive it when I did. It is great to know that now Arimidex is available to more women like me and they too can be offered the same opportunity."

As with all treatment decisions, women with breast cancer and their physicians should assess the benefits and risks of the treatment.

Patients feel left in the dark when discussing breast cancer treatments
Coinciding with the indication approval, results from a new UK survey of postmenopausal women with breast cancer released today reveal that 75% want to be more actively involved in making decisions about their treatment choice. The results of over 130 patients, conducted in association with the breast cancer charity, Abreast, indicate that 72% identify stopping their cancer coming back, above all else, as their main priority when receiving a treatment. Yet, despite this, 53% of patients felt they were not given enough information about the treatment choices available to them and 63% felt they were unable to fully input into their treatment decision.

In addition, the survey revealed that currently 69% of patients are unaware that the risk of breast cancer recurrence is particularly high in the two-year period at the start of treatment.

"This survey reveals that patients' wishes should be considered carefully by oncologists when selecting a treatment option, and that women should be given the opportunity to become more informed and involved in decisions made about how they are treated", commented Zoe Winters, a breast cancer surgeon and the founder of Abreast.

The new indication now states that the drug may be used in the adjuvant treatment of postmenopausal women with hormone receptor positive early invasive breast cancer.

:: Full Indication: In the UK, Arimidex (anastrozole) is approved for use in the adjuvant treatment of postmenopausal women with hormone receptor positive early invasive breast cancer. It has been licenced for the treatment of advanced breast cancer since 1995,[6] and now has over a million patient years experience worldwide.[7]

About the ATAC trial
- The ATAC trial compares five years of treatment with tamoxifen to five years of treatment with anastrozole, in women newly diagnosed with early breast cancer. 84% of patients in the trial had tumours which are known to respond to hormonal treatment.[1]

- The recent definitive analysis shows that, in the population of women whose tumours are fuelled by oestrogen, completing five years' adjuvant treatment with Arimidex provides additional benefits, over and above those offered by the previous standard of care, tamoxifen, with a further:

- 26% reduction in the risk of recurrence (HR =0.74; p= - 53% reduction in the risk of contralateral breast cancer recurrence (i.e. in the opposite breast) (HR = 0.47; p = 0.001).[1]

[1]. The ATAC Trialists' Group. Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years' adjuvant treatment for breast cancer, Lancet 2005; 365: 60-62
[2]. Osborne CK. Heterogeneity in Hormone Receptor Status in Primary and Metastatic Breast Cancer. Seminars in Oncology 1985; 12 (3): 317-26
[3]. Baum, M et al. An exploration of relapse data by hazard rate as a means of developing biological insights into the natural history and treatment of breast cancer: data from the `Arimidex', Tamoxifen, Alone or in Combination (ATAC) trial and the Milan Institute database. Presentation at the 41st Annual Meeting of the American Society of Clinical Oncology, 16 May 2005
[4]. Early Breast Cancer Trialists' Collaborative Group. Tamoxifen for early breast cancer: an overview of the randomised trials. Lancet 1998;351:1451-67
[5]. Saphner T, Tormey DC, Gray R. Annual hazard rates of recurrence for breast cancer after primary therapy. J Clin Oncol. 1996 Oct;14(10):2738-46
[6]. Arimidex SmPC, August 2004
[7]. AstraZeneca UK: Data on File ARIM/15/March 2004
[8]. Cancer Research UK website. version=2

Source: AstraZeneca

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