EPS-1421

EPS-1421 is a novel, potent, and selective oral small molecule inhibitor of KIT (also known as c-Kit or stem cell growth factor receptor), developed by Enanta Pharmaceuticals. It is designed to treat chronic spontaneous urticaria and potentially other indications by depleting mast cells, thereby addressing a primary driver of these diseases. Preclinical data show that EPS-1421 inhibits KIT with nanomolar potency in both binding and cellular assays, demonstrates sub-nanomolar activity in vivo, and exhibits high selectivity for KIT over other kinases. The compound has shown favorable in vitro and in vivo ADME properties. As of early 2025, the drug is undergoing scale-up activities and IND-enabling studies.