AstraZeneca has announced that it has received European marketing approval for its new breast cancer drug Faslodex™ (fulvestrant). The drug is indicated for the treatment of postmenopausal women with receptor-positive locally advanced or metastatic breast cancer, for disease relapse or progression on or after therapy with an anti-estrogen such as tamoxifen. Faslodex has been launched in the USA since May 2002, and more recently in Brazil in July 2003.

Hormonal agents such as aromatase inhibitors and tamoxifen are standard therapy in postmenopausal women with advanced breast cancer, providing an effective and well-tolerated treatment option. However, in time tumor cells can grow resistant to treatment with these hormonal therapies and as a result there is a need for new agents to which tumors are not resistant.

Faslodex is a novel therapy, the first of a new type, with a unique mode of action. The drug is an estrogen receptor antagonist with no agonist effects that binds, blocks and degrades the estrogen receptor in breast cancer cells. This mode of action is different to the aromatase inhibitors that work by reducing the amount of estrogen in a woman's body. It is also different to tamoxifen, which blocks the estrogen receptor but which also has some estrogenic actions which can be associated with a number of unwanted side effects.

Faslodex's unique mode of action creates a new type of endocrine treatment for estrogen receptor positive breast cancer - the first to be approved in the European Union since 1995.

Faslodex offers durable responses and has tolerability benefits compared with aromatase inhibitors and tamoxifen. Faslodex is effective following disease progression on prior anti-estrogen and aromatase inhibitor therapy; in addition both therapies are effective following Faslodex therapy. According to AstraZeneca, Faslodex therefore meets a key unmet need for women with advanced breast cancer, since it can be added in to the sequence of well-tolerated hormonal therapies and may delay the need to resort to cytotoxic chemotherapies with their accompanying side effects.

Professor John Robertson, from the University of Nottingham, UK, welcomed the launch of Faslodex and commented on the benefit that the new drug brings: "The arrival of this new type of treatment is particularly exciting as it brings with it new choices for postmenopausal women with the advanced stages of this disease."

He continued, "The addition of a new endocrine agent expands our options for endocrine treatment sequences, and potentially allows us to control the disease for longer. Faslodex is likely to appeal to women as it may help delay the need for cytotoxic chemotherapies. In addition Faslodex has a very good side effect profile and offers tolerability benefits over other standard endocrine therapies."

SOURCE:
AstraZeneca (http://www.astrazeneca.com)