AC0682

AC0682 is an investigational orally bioavailable small molecule chimeric degrader of estrogen receptor alpha (ERα), developed for the potential treatment of ER-positive/HER2-negative breast cancers. It functions as a proteolysis-targeting chimera (PROTAC), selectively binding to and inducing degradation of ERα protein—including both wildtype and mutant forms—thereby inhibiting the hormone-regulated transcription factor that drives tumor initiation and proliferation in approximately 80% of breast cancers. Preclinical studies have shown potent and selective ERα degradation with favorable pharmacological properties, including brain penetration and promising anti-tumor activity in animal models. The drug was being evaluated in Phase 1 clinical trials for patients with locally advanced or metastatic ER-positive/HER2-negative breast cancer but these trials were terminated following a strategic shift by the developer[1][2][3][4][5][7].