Dr. Hamilton on the Mechanism of Action of OP-1250 in HR+/HER2- Metastatic Breast Cancer

Erika P. Hamilton, MD, director of the Breast Cancer and Gynecologic Cancer Research Program and principal investigator at the Sarah Cannon Research Institute, discusses the mechanism of action of OP-1250 in patients with hormone receptor–positive, HER2-negative metastatic breast cancer.

OP-1250 is a complete estrogen receptor antagonist, says Hamilton, and these drugs fall within the same class as novel endocrine agents like selective estrogen receptor degraders (SERD), selective androgen receptor modulators, and selective estrogen receptor covalent antagonists. 

The agent is not only able to degrade estrogen receptors (ER) as a SERD does, but it also inactivates and becomes an ER antagonist, explains Hamilton. OP-1250 has unique properties that might make it well-suited for use in this patient population, as it demonstrates activity in both wild-type and ESR1 preclinical models and deactivates the AF1 and AF2 domains, Hamilton concludes.