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

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

June 05, 2006

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

    MACCLESFIELD, England, June 5 /Xinhua-PRNewswire/ --
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 
http://www.astrazenecapressoffice.com and
http://BreastCancerSource.com

    For more information, please contact:

     Lynn Grant
     Global PR Director, Oncology
     AstraZeneca, Direct Line
     Tel:    [phone] 
     Mobile: [phone]
     Email:  [e-mail]

     Elly Brookes
     Mobile: [phone]
     Email:  [e-mail]

     Sara Singer
     Mobile: [phone]
     Email:  [e-mail]

SOURCE  AstraZeneca