Femara tops Arimidex in quality of life/ tolerability assessment

A new comparative study looking at the two most widely-used aromataseinhibitors in breast cancer treatment, Novartis' Femara (letrozole) and AstraZeneca's Arimidex (anastrozole), has found that the former offers better tolerability in women with stabilized, postmenopausal breast cancer. The results have been presented at the European Breast Cancer Conference, held in Barcelona, Spain, March 19-23.

The lead investigator in the study, Robert Thomas of Addenbrooke's Hospital in Cambridge, UK, and Bedford Hospital National Health Service Trust, told a news conference that the study answers an important question in the management of this patient group, particularly as the use of aromatase inhibitors is on the increase. He now believes that Femara should be the first aromatase inhibitor selected, with patients switching to Arimidex if they do not do well on Novartis' drug. This would effectively turn the current prescribing pattern for the two drugs on its head in the UK, where Arimidex has by far the greatest market share, although Femara is more widely-used outside the UK, according to Dr Thomas.

The study enrolled 72 patients (69 evaluable) and used an investigator-blinded crossover design, in which patients received either Arimidex (1mg od) or Femara (2.5 mg od) for four weeks, had a week-long washout period, then switched to the other drug for a further four weeks. The patients enrolled in the trial had no prior exposure to aromatase inhibitors but had been treated with tamoxifen, and their disease was under control. Quality of life and side effects were assessed using a new questionnaire (FACT-ES) which was completed by the patients at home. After the second treatment phase, the women could continue treatment with their preferred drug.