AstraZeneca has received Japanese regulatory approval for Faslodex (fulvestrant) 500mg, an oestrogen receptor antagonist for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer.

Faslodex disrupts oestrogen signalling, causing down-regulation of the oestrogen receptors in the tumour. This can not only reduce the growth and spread of the cancer, but also to reduce or delay resistance to treatment.

The results of a Phase III study led to the approval of Faslodex 500mg in Europe in March 2010 and the US in September 2010.

AstraZeneca Global Commercial Organisation executive vice-president Tony Zook said that metastatic breast cancer treatment primarily aims to prevent disease progression besides maintaining quality of life and Faslodex 500mg will provide women with better control over the disease.

It plans to introduce Faslodex 500mg in Japan by the end of 2011, the company said.