Septerna has dosed the first participants in a Phase 1 trial of SEP-631, an oral, selective, small molecule Mas-related G protein-coupled receptor X2 (MRGPRX2) negative allosteric modulator (NAM). The study will assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of SEP-631 in healthy adult volunteers using both single-ascending and multiple-ascending dose regimens.
This first-in-human trial represents a crucial step for Septerna’s foray into mast-cell-driven diseases, a therapeutic area with substantial unmet need. Chronic spontaneous urticaria (CSU), a common inflammatory skin condition characterized by recurring hives and angioedema, serves as the initial target indication. The company’s focus on MRGPRX2, a key receptor in mast cell activation, aims to address the significant patient population that remains unresponsive to standard antihistamine therapies.
Septerna’s strategy hinges on the potential of SEP-631 to offer a convenient oral alternative to existing CSU treatments. The company emphasizes the drug’s selectivity for MRGPRX2, suggesting it could minimize off-target effects. This selectivity is a product of Septerna’s Native Complex Platform, a technology designed to enhance GPCR drug discovery. The platform’s potential extends beyond CSU, as MRGPRX2 is implicated in other conditions like asthma, atopic dermatitis, and migraine, offering avenues for pipeline expansion.
The Phase 1 trial, enrolling up to 150 healthy volunteers, includes an icatibant skin challenge in the multiple-ascending dose portion to assess pharmacodynamic effects. This approach is designed to demonstrate the drug’s impact on mast cell degranulation in a controlled setting. The results will be critical for informing future clinical development, particularly as the company navigates the increasingly complex landscape of personalized medicine and stratified patient populations.
Looking ahead, success in this Phase 1 trial would set the stage for efficacy studies in CSU patients. Septerna will likely face competition from other companies pursuing oral therapies targeting mast cell activation pathways. Differentiating SEP-631 through a superior safety profile and demonstrable efficacy in a broad patient population will be essential. The company will also need to generate data supporting long-term disease control to gain traction with payers in a market already served by biologics.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
