ERX-11

ERX-11 is a first-in-class small molecule modulator of estrogen receptor (ER) coregulator interactions, primarily developed for the treatment of ER-positive breast cancer. Unlike traditional endocrine therapies that target the ligand-binding pocket of the receptor, ERX-11 disrupts the interaction between the ER and its transcriptional coregulators. This unique mechanism of action allows it to maintain efficacy in models of acquired resistance to tamoxifen and letrozole, as well as in cancers harboring ER mutations. Developed through a collaboration between the University of Texas Health Science Center at San Antonio, UT Southwestern, and UT Dallas, ERX-11 has demonstrated anti-tumor activity in preclinical xenograft and patient-derived explant models and served as the lead compound for the development of optimized analogs such as ERX-41.