Fulvestrant

Fulvestrant is a selective estrogen receptor degrader (SERD) that downregulates and degrades estrogen receptor ? (ER?).{16606,43228} It binds to rat uterine ER with an IC50 value of 44.8 nM and prevents uterine weight increases induced by estradiol in immature rats (ED50> = 0.06 mg/kg per day) but has no effect on uterine weight alone.{43229} It also decreases uterine weight in adult rats without affecting the production of luteinizing and follicle-stimulating hormones and prolactin. Fulvestrant inhibits the growth of ER-positive MCF-7 human breast cancer cells but not ER-negative BT-20 cells when used at a concentration of 1 µg/ml. It also prevents tumor growth in MCF-7 and Br10 breast cancer mouse xenograft models when used at a single dose of 5 mg per animal. Fulvestrant is neuroprotective in vitro against neurotoxicity induced by glutamate- and amyloid-? (1-42) (A?42) in primary rat hippocampal cells.{16605} Formulations containing fulvestrant have been used in the treatment of estrogen-sensitive breast cancer.