ERα degrader-2 is a selective estrogen receptor degrader ( SERD ) with potent binding affinity with ERα ( IC 50 =17.1 nM), good degradation efficacy ( EC 50 =0.3 nM). ERα degrader-2 exhibits favorable pharmacokinetic properties and excellent agentgability, can be used for HER + breast cancer research In Vitro ERα degrader-2 (0.01-40 nM) decreases ERα expression and not fully degrades ERα in MCF-7 cells even at a higher biochemical concentration in MCF7 cells. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo ERα degrader-2 (oral administration; 2-6 mg/kg; QD; 21 days) leads to the significant tumor growth inhibition and decreases tumor volume in mice . ERα degrader-2 (oral gavage; 2 mg/kg; single dose) possesses better pharmacokinetic properties than AZD9496, the plasma exposure (AUC) is 16073.7 h*ng/mL, and the half-life period is 12.1 h, the oral availability is 80.5% . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: MCF-7 human breast cancer xenograft model in nude mice Dosage: 2 mg/kg; 6 mg/kg Administration: Oral administration; 2-6 mg/kg; QD; 21 days Result: Exhibited in vivo efficacy in breast cancer xenograft model. Form:Solid IC50& Target:ERα 4.6 nM (IC 50 )