H3B-6545

H3B-6545 is an orally available, selective estrogen receptor alpha (ERα) covalent antagonist developed for the treatment of estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) advanced or metastatic breast cancer. It acts by selectively and covalently binding to a cysteine residue unique to ERα, thereby inhibiting both wild-type and mutant forms of the receptor—including those with activating ESR1 mutations that confer resistance to standard endocrine therapies. This inhibition blocks ERα-driven tumor cell proliferation and survival. Preclinical studies have shown that H3B-6545 is effective against both CDK4/6 inhibitor-naïve and -resistant tumors. Clinical trials have demonstrated antitumor activity in heavily pretreated patients with ER+, HER2– breast cancer[2][6][7].

Other names

SERCA H3B-6545Selective Estrogen Receptor Covalent Antagonist H3B-6545