Fulvestrant ("Faslodex"): clinical experience from the Compassionate Use Programme

Fulvestrant ("Faslodex") is a new oestrogen receptor (ER) antagonist with no agonist effects that is licensed in the USA, Brazil, Europe and elsewhere for the treatment of advanced breast cancer (ABC) in postmenopausal women following progression on other endocrine agents. This report consolidates clinical experience from the "Faslodex" Compassionate Use Programme, including a total of 339 patients treated at eight cancer centres. Patients received fulvestrant as first- (n=22), second- (n=125), third- (n=105), fourth- (n=58), fifth- (n=22) or sixth-line (n=5) hormonal treatment for ABC, with two patients receiving fulvestrant after more than six other endocrine therapies. Objective response was achieved by 40 patients and stable disease lasting 6 months by 92 patients, giving overall clinical benefit (CB) in 132/339 patients (39%). The CB rate decreased as fulvestrant was used later in the sequence of endocrine treatments, from 46% (10/22) with first-line fulvestrant to 27% (6/22) with fifth-line fulvestrant. Increased benefit was found in patients with tumours expressing both ER and progesterone receptor (PgR) compared with other combinations, although good activity was reported in patients expressing either ER or PgR as well as in tumours expressing human epidermal growth factor receptor 2. Fulvestrant was well tolerated; adverse events were noted in 18/339 patients (5%). These findings concur with data from the clinical-trial setting and further support the assertion that greater benefit is derived when fulvestrant is used early in the treatment sequence.