New licence allows patients to switch to Arimidex
pharmafile | July 14, 2006 | News story | Sales and Marketing |Â Â Â
AstraZeneca has gained a new licence for its breast cancer drug Arimidex to allow patients to switch from tamoxifen after two to three years – which trials suggest can significantly improve a woman's chances of staying free of cancer.
The new licence for Arimidex is AstraZeneca's latest tactic in challenging the 'gold standard' status of tamoxifen, which has been the number one choice for around 25 years as a post-surgery treatment to prevent cancer returning.
Arimidex has been on the market since 1995, but has still not superseded tamoxifen as the first choice, despite evidence which suggests it is superior to the older drug when used directly after surgery.
Doctors will now be able to switch patients to Arimidex after two to three years of treatment on tamoxifen, creating a new opportunity for women to receive the drug.
Prof Walter Jonat of the University of Kiel, Germany, said: "Physicians are increasingly using Arimidex at diagnosis because of its superior efficacy and tolerability compared with the old gold standard, tamoxifen.
"The question remained whether those patients who did not receive Arimidex from the start of their treatment would still be able to benefit. This new indication means we can now also offer them a greater likelihood of living longer, cancer-free, by changing therapy to Arimidex. It will also reduce the risk of patients experiencing some of the long-term side effects associated with tamoxifen."
Arimidex is the most widely prescribed drug in the class of newer breast cancer drugs called aromatase inhibitors, which also includes Novartis' Femara and Pfizer's Aromasin.
The approval is for the adjuvant treatment of early breast cancer in oestrogen-receptor-positive postmenopausal women who have received two to three years of adjuvant tamoxifen.
The new indication is based on extensive data from three key international trials – the Austrian Breast & Colorectal Cancer Study Group (ABCSG-8), the Arimidex-Nolvadex (ARNO-95) and the Italian Tamoxifen Arimidex (ITA), specifically designed to investigate the effects of changing treatments in women already receiving tamoxifen for early breast cancer.
In the UK, the aromatase inhibitors look set to finally supersede tamoxifen, with NICE poised to recommend them as first-line choice in forthcoming guidance.
The clinical and cost effectiveness body has already published preliminary recommendation for the drugs as first post-surgery (adjuvant) treatment for oestrogen-receptor-positive breast cancer, and is due to issue its final guidance on the treatments in November – but patient groups are emphasising that clinicians can prescribe these three aromatase inhibitors before then.
Around 23,000 women are diagnosed with early breast cancer each year in the UK and Arimidex is currently the most popular aromatase inhibitor prescribed.
NICE has found no evidence so far to suggest one aromatase inhibitor is more clinically effective than another, but AstraZeneca will be well placed to exploit Arimidex's lead in the market.
Arimidex achieved sales of 36 million pounds in sales through prescriptions written in the community in England in 2005, with Femara on 6.9 million pounds and Aromasin achieving 4.3 million pounds.
