Ospemifene

Ospemifene (FC-1271a) is an orally active and non-estrogenic selective estrogen receptor modulator (SERM) with K_i values of 380 and 410 nM for estrogen receptor α (ERα) and ERβ, respectively. Ospemifene inhibits caspase-3 activity. Ospemifene inhibits neuronal degeneration, prevents bone loss, and increases vaginal weight and vaginal epithelial height. Ospemifene has anticancer activity against breast cancer^{[1][2][3][4][5][6]}. In Vitro:Ospemifene (100 pM-30 μM) binds with essentially comparable affinity to the ER-α and ER-β isoforms and effectively antagonize ERE-mediated transactivation in MCF-7 cells^[1].
Ospemifene (0.1 nM-10 μM) does not significantly promote the growth of MCF-7 cells^[3].
Ospemifene (0.1-10 μM; 4-6 days) inhibits the growth of MCF-7 cells and has no significant effect on the growth of MDA-MB-231 cells^[4].
Ospemifene (0.1-10 μM; posttreatment) decreases hypoxia- and ischemia- induced LDH release, caspase-3 activity, neuronal cell degeneration in primary neocortical cell cultures subjected to hypoxia and/or ischemia^[5].
In Vivo:Ospemifene (10-100 mg/kg/day; p.o.; once daily; 14-28 days) increases vaginal weight and has a greater effect on increasing vaginal epithelial height compared with Raloxifene (HY-13738) in ovariectomized rats^[1].
Ospemifene (1-10 mg/kg; p.o.; 4 weeks) can prevent bone loss, maintain the trabecular bone volume of the distal femur, prevent the decrease of bone strength in ovariectomized rats^[3].
Ospemifene (10-100 mg/kg; p.o.; once daily; 7 days) inhibits the growth of MCF-7 tumors in the athymic, ovariectomized mouse model with MCF-7 human tumor xenografts^[4].
Ospemifene (5-50 mg/kg; p.o.; daily) effectively prevents breast cancer in the MTag.Tg transgenic mouse model^[6].