Fulvestrant (Faslodex™) in advanced breast cancer: clinical experience from a Belgian cooperative study

Fulvestrant (Faslodex™) is a new estrogen receptor (ER) antagonist with no agonist effects that is licensed for the treatment of postmenopausal women with hormone-sensitive advanced breast cancer (ABC) who have progressed/recurred on prior antiestrogen therapy. The Faslodex™ Compassionate Use Program (CUP) provides expanded access to fulvestrant in countries where it is not yet available for patients who are not eligible to enter clinical trials. This analysis pools data from 402 patients who received fulvestrant as part of the CUP in Belgium, predominantly as 3rd- to 5th-line endocrine therapy for ABC. Two patients experienced partial responses and 118 experienced stable disease lasting ≥6 months, resulting in an overall clinical benefit rate of 29.9%. Fulvestrant was active in patients with multiple sites of metastases, visceral metastases, human epidermal growth factor receptor 2-positive disease and after heavy endocrine pre-treatment. Fulvestrant was well tolerated, with only six patients (1.5%) discontinuing treatment following adverse events. These data support the findings of previous CUP analyses and Phase II and III trials, suggesting that fulvestrant is a valuable addition to the treatment sequence for postmenopausal women with ABC who have progressed/recurred on prior endocrine therapy.