ABSTRACT

A new anti-oestrogen devoid of agonist activity was described for the first time: ICI 182,780 (now known as fulvestrant (Faslodex)). The compound was 10 times more potent than the prototype pure anti-oestrogen ICI 164,384. The structure of these compounds was a departure from all earlier anti-oestrogens, in that they were steroids and identical to oestradiol, save for a long aliphatic, polyfluorinated side-chain at carbon 7 of the chemical structure. The compound had similar binding affinity for the oestrogen receptor as oestradiol.