SEP-631

SEP-631 is a selective, oral small molecule negative allosteric modulator (NAM) of the Mas-related G protein-coupled receptor X2 (MRGPRX2). MRGPRX2 is highly and uniquely expressed on mast cells and plays a key role in mast cell activation and degranulation, which are central to the pathogenesis of several mast cell-driven diseases. By inhibiting MRGPRX2, SEP-631 aims to block mast cell activation regardless of the activating agonist. Preclinical studies have shown that SEP-631 potently inhibits MRGPRX2-mediated responses in human mast cells with low nanomolar IC50 values and demonstrates long target residence time, suggesting potential for prolonged therapeutic action. The drug is being developed primarily for chronic spontaneous urticaria but may also have applications in other conditions driven by aberrant mast cell activity such as allergic asthma, atopic dermatitis, and prurigo nodularis[1][4][5][7].