fosfestrol

Fosfestrol (diethylstilbestrol diphosphate) is a synthetic nonsteroidal estrogen and a prodrug of diethylstilbestrol (DES), specifically developed for the treatment of advanced prostate cancer. It is designed to be relatively inactive until it is hydrolyzed by the enzyme acid phosphatase, which is found in high concentrations in prostatic tissue and prostate cancer cells. Upon hydrolysis, it releases diethylstilbestrol, which acts as a potent estrogen receptor agonist. Its primary therapeutic mechanism involves the suppression of the hypothalamic-pituitary-gonadal axis, leading to a reduction in luteinizing hormone (LH) secretion and a subsequent decrease in serum testosterone to castrate levels. Beyond its hormonal effects, fosfestrol may also exert direct cytotoxic and antimitotic effects on tumor cells. While historically widely used, it has largely been replaced in modern clinical practice by LHRH agonists and newer antiandrogens due to significant cardiovascular and thromboembolic risks associated with high-dose estrogen therapy.

Brand names

HonvanStilphostrolHonvolStilbestrol-P

Other names

diethylstilbestrol diphosphatefosfestrol tetrasodiumdiethylstilboestrol diphosphate