Elacestrant

Elacestrant (RAD1901) is an orally available and selective estrogen receptor degrader (SERD) with IC₅₀s of 48 and 870 nM for ERα and ERβ, respectively. Elacestrant also can inhibit growth of ER⁺ breast cancer cell lines in vitro and in vivo^[1][2]. IC50 & Target:IC50: 48 nM (ERα), 870 nM (ERβ)^[1] In Vitro:Elacestrant (RAD1901; 0.5 nM-10 µM; 48 h) exhibits dose-dependent inhibition of ERα expression, with a EC₅₀ of 0.6 nM in MCF-7 cells^[1].
Elacestrant (0-1 µM; 48 h) inhibits proliferation of Estradiol (E2)-stimulated MCF-7 cells in a dose-dependent manner, with an EC₅₀ of 4 pM^[1].
Elacestrant (0-1 µM; 24 or 48 h) results in a dose-dependent and marked decrease in estrogen receptor protein expression in MCF7, T47D, and HCC1428 cells^[2].
Elacestrant (0.01, 0.1, 1.0 µM) decreases expression of progesterone receptor (PGR, PR; an ER target gene), in both MCF7 and T47D cell lines^[2]. In Vivo:Elacestrant (0.3-120 mg/kg; p.o.; single daily for 40 days) antagonizes E2-mediated uterine stimulation in a dose-dependent manner in vivo^[1].
Elacestrant (30, 60 mg/kg; p.o.; single daily for 4 weeks) induces complete tumor growth inhibition in mice^[2].
Tumor growth inhibition is maintained for 4 weeks after Elacestrant withdrawal^[2].