Clinical Experience for 'Arimidex' (anastrozole) Passes Two Million Patient Years (i) Milestone

Macclesfield, England (ots/PRNewswire) -

- Evidence Drives More Clinicians to Choose anastrozole as
Optimal Hormonal Therapy for Postmenopausal Women With Early
Breast Cancer

AstraZeneca announced today, from the American Society of Clinical
Oncology (ASCO) Annual Meeting, that anastrozole has this month
become the first aromatase inhibitor (AI) to accumulate over two
million patient years' clinical experience. Since the mature results
from the ATAC(i) trial clearly established the superiority of
anastrozole over tamoxifen in early breast cancer(1), anastrozole has
become the world's most used AI.

Commenting on this treatment revolution, Dr Buzdar of the MD
Anderson Cancer Centre in Texas said: "When deciding what's best for
our patients, we look to clinical evidence and guidelines to lead our
choices. Anastrozole has consistently demonstrated that it's more
effective and better tolerated than tamoxifen. Guidelines are now
strongly recommending the use of an AI in early breast cancer
patients and anastrozole has the most experience and strongest
evidence. It's not surprising then, that doctors are increasingly
choosing it to help their patients stay free from breast cancer after
surgery, whilst avoiding some of the unpredictable and sometimes
serious side effects that they risk with tamoxifen."

Bone health in postmenopausal women taking aromatase inhibitors

In recommending the use of AIs such as anastrozole in early breast
cancer, recent treatment guidelines have also highlighted that
additional evidence was needed regarding the effect of AIs on bone
strength. A 5-year update from the ATAC bone-sub-protocol, also
presented today at ASCO confirms that, if women have a normal bone
mineral density (BMD) at the outset, they can undergo a 5-year course
of treatment with anastrozole without the risk of developing
osteoporosis.(2) These data have generated much excitement in the
medical community as it is the first time that long-term data have
been available on the effects of an AI on bone.

Although a reduction in BMD does occur over the 5-year course of
treatment with anastrozole, the rate of bone loss slows down
significantly after the first 2 years. Normal reduction in BMD
associated with ageing is approximately 2-3% over 5 years; the bone
loss seen with anastrozole is slightly higher (average, 6.1% in the
lumbar spine and 7.2% in the hip) but is not significant enough to
lead to osteoporosis (bone loss of 15-20%). Separate data have also
supported the fact that the rate of bone fracture among women taking
anastrozole is comparable to the normal patient population of that
age group.(3,4) Clinicians who may have previously been reluctant to
prescribe anastrozole, because of the unconfirmed effect on bone, can
now be more confident that it not only offers their patients a
significantly better chance of staying cancer-free, any side effects
such as a reduction in bone strength are predictable and manageable.

Switching from tamoxifen to anastrozole

Additional data presented at ASCO today further support the
benefits of anastrozole over tamoxifen. Although it is clear that
postmenopausal women with early breast cancer gain the greatest
benefit from starting anastrozole treatment immediately after
surgery, those who have already commenced treatment with tamoxifen do
not have to miss out on the superior efficacy and tolerability of the
newer drug. New data from the prospective 'Arimidex'-'Nolvadex' 95
(ARNO) study are the first data from a single trial to confirm that
stopping tamoxifen and switching to anastrozole can potentially save
lives.(5) These data are consistent with previous meta-analysis data
from three trials (presented at SABCS(iii) 2005)(6) which also
demonstrated an improvement in overall survival among women who
switched treatments.

"It's reassuring to know that the data for anastrozole continue to
justify the confidence that we as clinicians already have in
selecting it as the optimal treatment for our postmenopausal early
breast cancer patients. The increasing evidence base for AIs
continues to confirm that tamoxifen is not the most effective or safe
drug we can offer our patients to keep them free from recurrence,"
concluded Dr Buzdar.

References

1. ATAC Trialists' Group. Lancet 2005; 365: 60-62.

2. Coleman R. Proceedings of the American Society of Oncology
(ASCO),2006. Abs 511.

3. Fisher B et al. J Natl Cancer Inst 1998; 90: 1371-1388.

4. Women's Health Initiative Writing Group. JAMA 2002; 288:
321-333

5. Kaufmann M. Proceedings of the American Society of Oncology
(ASCO), 2006. Abs 547.

6. Jonat W. Proceedings of the San Antonio Breast Cancer
Symposium, 2005

Notes to Editors

(i) Patient years calculations: Patient takes one tablet per day
and there are 365 days per year.

Therefore, total tablets sold since launch divided by 365 =
number of patient years

(ii) ATAC Trial: 'Arimidex' Tamoxifen, Alone or in Combination

(iii) SABCS: San Antonio Breast Cancer Symposium

AstraZeneca is a major international healthcare business engaged
in the research, development, manufacture and marketing of
prescription pharmaceuticals and the supply of healthcare services.
It is one of the world's leading pharmaceutical companies with
healthcare sales of $23.95 billion and leading positions in sales of
gastrointestinal, cardiovascular, neuroscience, respiratory, oncology
and infection products. AstraZeneca is listed in the Dow Jones
Sustainability Index (Global) as well as the FTSE4Good Index.

'Arimidex' is a trademark, the properties of the AstraZeneca
group of companies.

For further information, please visit our websites
www.astrazenecapressoffice.com and BreastCancerSource.com

Originaltext: AstraZeneca
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Lynn Grant, AstraZeneca, Global PR Director, Oncology,
Direct Line: +44-1625-517-406, Mob: +44-7715-484-917,
Email: Lynn.Grant@Astrazeneca.com.
Elly Brookes, Shire Health International,
Mob: +44-7768-553-210,
Email: elly.brookes@shirehealthinternational.com.
Sara Singer, Shire Health International,
Mob: +44-7881-810-328,
Email: sara.singer@shirehealthinternational.com