What is Faslodex?
Faslodex is a solution for injection containing the active substance fulvestrant, available in 250 mg pre-filled syringes.
What is Faslodex used for?
Faslodex is indicated for the treatment of post-menopausal women suffering from locally advanced or metastatic breast cancer, when the tumor is positive for estrogen receptors (ie when tumor cells are equipped with estrogen hormone receptors on their surface ). The term "metastatic" means that the tumor has spread to other parts of the body. Faslodex is indicated in disease relapse during or after therapy with an "antiestrogen" (a type of drug used to treat breast cancer) or when the disease has progressed during anti-estrogen therapy.
The medicine can only be obtained with a prescription.
How is Faslodex used?
The recommended dose of Faslodex is 250 mg once a month, given by slow injection into the buttock. Faslodex should be used with caution in patients with liver problems or severe kidney problems. It must also not be used by patients with severe hepatic impairment.
How does Faslodex work?
Most breast cancers develop in response to the hormone estrogen. The active substance in Faslodex, fulvestrant, is an antiestrogen. It binds to the estrogen receptors present on the surface of the cells, where it acts by blocking the effects of the hormone and inducing a reduction in the number of estrogen receptors. As a result, cancer cells are not stimulated to grow by estrogens and tumor proliferation is reduced.
Faslodex is slowly absorbed by the body and the effects of each injection last more than a month. Concentrations of the drug in the body increase with the succession of injections, reaching a steady state after about six injections.
How has Faslodex been studied?
The effects of Faslodex were first tested in experimental models before being studied in humans. Faslodex has been studied in two main studies involving 1, 014 postmenopausal women with advanced breast cancer, relapse or progression after previous hormone therapy. Both studies compared the effects of two dosage regimens of Faslodex (125 mg and 250 mg per month respectively) with those of anastrozole (another anticancer medicine) taken daily at a dose of 1 mg. In the first study the patients knew which drug they were taking, while in the second they were unaware of it. For both studies, the main measure of effectiveness was how long the disease progressed.
What benefit has Faslodex shown during the studies?
Faslodex was as effective as anastrozole. Looking at the results of both studies, it was found that in patients treated with 250 mg Faslodex once a month, an average of 166 days had elapsed before the disease progressed, compared with 126 days in patients treated with anastrozole. The 250 mg dose of Faslodex was found to be more effective than the 125 mg dose.
What is the risk associated with Faslodex?
The most common side effect with Faslodex (seen in more than 1 patient in 10) is hot flushes. For the full list of all side effects reported with Faslodex, see the Package Leaflet.
Faslodex should not be used in people who may be hypersensitive (allergic) to fulvestrant or any of the other ingredients. Faslodex should not be used during pregnancy or lactation, or by patients suffering from severe liver disease.
Why has Faslodex been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that the benefits of Faslodex outweigh its risks for the treatment of postmenopausal women suffering from locally advanced or metastatic breast cancer, positive for estrogen receptors, in disease relapse during or after adjuvant antiestrogenic therapy or disease progression during therapy with an antiestrogen, and has therefore recommended that it be given marketing authorization.
More information on Faslodex:
On 10 March 2004, the European Commission granted a marketing authorization valid for Faslodex, valid throughout the European Union, to AstraZeneca UK Limited. The marketing authorization was renewed on 10 March 2009.
The full EPAR for Faslodex can be found here.
Last update of this summary: 03-2009
