Herceptin and ARIMIDEX(TM) Combination Improves Patient Outcomes in Advanced HER2-Positive Breast Cancer
Macclesfield, England (ots/PRNewswire)
- For International Journalists - Not for US Media
New data, presented for the first time today, show that a combination of ARIMIDEX(TM)(anastrozole) plus Herceptin (trastuzumab) is a better treatment option than hormonal therapy alone, for women with a certain type of advanced breast cancer(1). The new data, from the first study of its type, show that in a minority group of postmenopausal women with hormone-sensitive, HER2-positive* tumours, the addition of Herceptin to anastrozole keeps cancer under control for significantly longer than hormonal therapy alone (median progression-free survival = 4.8 months vs. 2.4 months respectively). The data were presented for the first time today at the 31st European Society for Medical Oncology (ESMO) Congress in Istanbul, Turkey.
Around two-thirds of postmenopausal women with breast cancer have hormone-sensitive disease and are therefore eligible for treatment with anastrozole. However, up to a quarter of these women will also be HER2-positive, which means that they have a particularly aggressive form of cancer, with a higher likelihood of relapse. For these particular women with so-called 'co-positive' cancers, the opportunity to take a combination of these two highly effective anti-cancer drugs will be a welcome addition to their treatment programme.
The data presented at ESMO today continue to highlight the current and future potential of anastrozole in breast cancer. Anastrozole was the first treatment shown to improve upon the efficacy and tolerability of tamoxifen in early breast cancer, resulting in significant changes to treatment practice. Now anastrozole becomes the first treatment of its kind to demonstrate a benefit in combination with Herceptin in advanced disease.
Anastrozole in early breast cancer
Additional data(2,3) presented for the first time in Europe at ESMO today, confirm the benefits of initiating hormonal adjuvant treatment with anastrozole. Postmenopausal women with hormone-sensitive, early breast cancer are 26% less likely to suffer a disease recurrence if treatment is started with anastrozole rather than tamoxifen. Data from the mature, 68-month analysis of the ATAC** trial, show that the majority of the recurrences seen with tamoxifen occur within the first few years of treatment, emphasising the importance of starting anastrozole treatment early(2).
"Preventing recurrence is the primary aim of adjuvant treatment - if the cancer doesn't come back, you can't die from it," explained Joan Houghton, who presented the data today on behalf of the ATAC Trialists' Group. "In the ATAC trial, over half of the additional recurrences seen with tamoxifen occurred within the first two and a half years of surgery. There may still be a place for tamoxifen in early breast cancer, but these data show us that treating women with anastrozole, from the outset, provides the optimal protection against early recurrence."
Importantly, women on anastrozole also suffered far fewer side effects compared with tamoxifen, meaning that a significantly greater number were able to complete their treatment(3). One of the major drawbacks of tamoxifen is that it is known to be associated with some rare but life-threatening side effects, the majority of which were also seen to occur in the first few years of treatment.
- Women who took anastrozole experienced fewer strokes, fewer DVTs and fewer gynaecological side effects than women who took tamoxifen, over a five year treatment period.
- Women on anastrozole were four times less likely to undergo a hysterectomy - a procedure often undertaken as a result of gynaecological abnormalities.
Side effects that were significantly increased with anastrozole compared with tamoxifen were fractures and joint disorders. When balanced against the life-threatening side effects of tamoxifen, the risk of fractures with anastrozole is seen as predictable and manageable and the risk:benefit ratio for adjuvant therapy is consistently in favour of anastrozole compared with tamoxifen.
Dr Aman Buzdar of the MD Anderson Cancer Centre in Texas, and Chair of the ATAC Steering Committee concluded: "Starting therapy with tamoxifen puts patients at risk of preventable recurrences and avoidable serious side effects. It took a long time for us to improve upon tamoxifen, but with the mature data we have now for anastrozole, we know we have a more effective and better tolerated treatment to help our patients stay free from breast cancer."
References
1. Kaufman, B. Trastuzumab plus anastrozole prolongs progression-free survival in postmenopausal women with HER2 positive, hormone-dependent metastatic breast cancer (MBC). Abstract no. LBA2, presented at the ESMO 2006, Istanbul, Turkey, 29th Sept - 3rd Oct 2006
2. Houghton, J on behalf of the ATAC Trialists' Group, Initial adjuvant therapy with anastrozole (A) reduces rates of early breast cancer recurrence and adverse events compared with tamoxifen (T). Abstract no 243, presented at the ESMO 2006, Istanbul, Turkey, 29th Sept - 3rd Oct 2006
3. Mansel, R on behalf of the ATAC Trialists' Group. Tolerability of anastrozole (A) compared with tamoxifen (T): mature data in the adjuvant setting Abstract no 244, presented at the ESMO 2006, Istanbul, Turkey, 29th Sept - 3rd Oct 2006
Notes to Editors:
- About hormone-sensitivity and HER2-positivity:
- In hormone-sensitive (or hormone receptor-positive) breast cancer, the tumour cells carry receptors on their surface which respond to certain hormones and stimulate the growth of the tumour. Approximately 60% of postmenopausal breast tumours are hormone-sensitive.
- In HER2-positive breast cancer, the tumours have an increased quantity of the HER2 protein on the surface of the cells. Tumours of this type are particularly aggressive. HER2-positivity affects around 20-30% of women with breast cancer.
** ATAC: 'ARIMIDEX', Tamoxifen, Alone or in Combination
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.
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Contact:Lynn Grant - AstraZeneca, Global PR Director - Oncology,
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Elly Brookes - Shire Health International, Direct Line:
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