H3B-6545 — Investigational Agent
Selective Estrogen Receptor Degrader · Phase 1/2 · Eisai
Mechanism of Action
H3B-6545 is an oral, covalent selective estrogen receptor covalent antagonist (SERCA) that irreversibly binds cysteine 530 of ERα, inactivating both wild-type and constitutively active ESR1-mutant receptors. This covalent engagement produces durable receptor shutdown.
Investigational Indications
- ER-positive/HER2-negative locally advanced or metastatic breast cancer