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| 3 December 2003 | 2003-12-03T00:00:00.0000000-00:00 |
| ARIMIDEX™ CHALLENGES TAMOXIFEN AS STANDARD ADJUVANT THERAPY IN POSTMENOPAUSAL WOMEN WITH EARLY BREAST CANCER
New data, announced today at the San Antonio Breast Cancer Symposium, USA, questions the role of tamoxifen as standard adjuvant therapy for postmenopausal women with hormone-sensitive early breast cancer. The ITA (Intergruppo Tamoxifen Anastrozole) Trial data suggests that patients who change their adjuvant therapy from tamoxifen to ‘ARIMIDEX’™ after two - three years, are less likely to experience a return of breast cancer than those who complete a five year course of tamoxifen. In addition, those patients who change to ‘ARIMIDEX’™, experience significantly fewer serious side effects than those who remain on tamoxifen. | The ITA data reinforce the findings of the landmark ATAC (‘ARIMIDEX'™ Tamoxifen Alone or in Combination) study, which have already shown ‘ARIMIDEX’™ to be a more effective treatment, with an overall more favourable tolerability profile than tamoxifen for newly diagnosed postmenopausal women with early breast cancer. These latest findings will help clinicians to determine the best course of treatment for women already taking tamoxifen and whether it will be beneficial to change therapy to ‘ARIMIDEX’™ before the course of tamoxifen is completed.
‘ARIMIDEX’™ is the most widely used aromatase inhibitor in the world and 2003 sales have increased by 56 per cent during the first nine months of 2003 to $372 million. It remains the world’s largest selling aromatase inhibitor and is market leader in nine of the major markets including the US, Japan, UK, Germany, France, Italy, Sweden, Canada and Netherlands. The early breast cancer market could be worth approximately $2 billion.
Dr Francesco Boccardo of the University and National Cancer Research Institute, Genoa, Italy and lead investigator in the ITA study, said “The future role of five years’ adjuvant therapy with tamoxifen as standard treatment has been cast into doubt ever since the ATAC trial results were first published. What the findings of the ITA trial now suggest is that even if a woman has been started on adjuvant tamoxifen, it appears that many of the benefits of anastrozole can still be achieved with a switch of therapy from tamoxifen after two - three years.”
Professor Jeffrey Tobias, University College Medical School and University College Hospitals added “The ATAC data clearly changed the treatment landscape for early breast cancer, suggesting that anastrozole has both efficacy and tolerability benefits over tamoxifen in newly diagnosed postmenopausal women. The question still remained, however, of what to do with patients already taking tamoxifen. We know that the majority of breast cancer recurrences occur in the first five years following diagnosis, so it is extremely important to get the initial treatment decision right. The ITA data are encouraging, as they suggest that women who commenced tamoxifen before the ATAC results were reported, may still have the opportunity of benefiting by a switch to anastrozole for the remainder of their treatment course.
” The benefits offered by ‘ARIMIDEX’™ in this first five year period, for either newly diagnosed patients, or for patients who have completed several years of tamoxifen treatment, are of considerable importance to both clinicians and the women they treat. Furthermore, tolerability is also a key issue in the adjuvant setting, when women typically take treatments for long periods of time. The overall favourable tolerability profile of ‘ARIMIDEX’™ compared with tamoxifen, especially with respect to the lower incidence of some serious side effects like endometrial cancer, thromboembolic events and strokes, is an additional major benefit for this drug treatment.
There remains a large number of women who were prescribed adjuvant tamoxifen before the results of the ATAC trial suggested there could be a preferable alternative endocrine therapy in the form of ‘ARIMIDEX’™. These latest data from the ITA trial are, therefore, likely to be received as good news by these women, who may be concerned about either the side effects or the effectiveness of their ‘older’ therapy. Until now, there has been no evidence to indicate whether or not these women would benefit from having their therapy changed mid-way through their five year tamoxifen course. Importantly, the ITA data now suggest this may be the case.
Anastrozole – marketed as ‘ARIMIDEX’™ – is approved worldwide for postmenopausal women with advanced disease. The drug is already approved as an adjuvant treatment for postmenopausal women with hormone receptor-positive early breast cancer in 25 countries (including the US, UK, Germany, Italy, Spain) and is now widely used in the treatment of early and advanced breast cancer in postmenopausal women with hormone-sensitive disease.
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Notes to Editors:
· Following surgery to remove a breast tumour, women are usually given a hormonal treatment for five years to help prevent the breast cancer from returning – this is known as ‘adjuvant’ therapy. Whilst revolutionising the treatment of breast cancer when it was launched, tamoxifen is unfortunately associated with a number of serious and even life-threatening side effects such as endometrial cancer, deep vein thrombosis and stroke.
· Anastrozole is a potent, highly selective, non-steroidal oral aromatase inhibitor used in the hormonal (endocrine) treatment of breast cancer in postmenopausal women.
· Tamoxifen is an anti-oestrogen and acts primarily to prevent oestrogen binding to its receptor at tumour sites. Tamoxifen has some partial oestrogenic activity, which may be responsible for the differences in its side-effect profile compared with anastrozole.
· Anastrozole acts differently to tamoxifen by blocking the production of oestrogen by the aromatase enzyme pathway – the primary source of oestrogen in postmenopausal women, whose ovaries no longer function.
· The current treatment strategy for hormone-sensitive early-stage breast cancer (cancer that has not spread beyond the breast) in postmenopausal women generally consists of initial surgery to remove the tumour, which may be followed by a course of chemotherapy and/or radiotherapy. Women will usually then go on to take a hormonal drug treatment — such as tamoxifen or anastrozole— for around five years to reduce the risk of the cancer recurring (this is known as “adjuvant therapy”).
· AstraZeneca continues its tradition of research excellence and innovation in oncology that led to the development of its current anti-cancer therapies including ‘ARIMIDEX’ (anastrozole), ‘CASODEX’ (bicalutamide), ‘FASLODEX’ (fulvestrant), ‘NOLVADEX’ (tamoxifen), ‘ZOLADEX’ (goserelin) and ‘TOMUDEX’ (raltitrexed) as well as a range of novel targeted products such as anti-proliferatives, anti-angiogenics, vascular targeting and anti-invasive agents. AstraZeneca is also harnessing rational drug design technologies to develop new compounds that offer advantages over current cytotoxic and hormonal treatment options. The company has over 20 different anti-cancer projects in research and development. · 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 top five pharmaceutical companies in the world with healthcare sales of over $17.8 billion and leading positions in sales of gastrointestinal, oncology, cardiovascular, neuroscience and respiratory products. AstraZeneca is listed in the Dow Jones Sustainability Index (Global and European) as well as the FTSE4Good Index.
‘Anastrozole ‘ARIMIDEX’ is a trademark, property of the AstraZeneca Group of Companies.
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