Septerna Reports Positive Phase 1 Data for SEP-631; Phase 2 Trials Set for 2026

Key Facts

1SEP-631 demonstrated robust, dose-dependent inhibition of skin wheal formation, with complete inhibition observed at doses as low as 10 mg once-daily.

2The drug was well-tolerated across all doses studied with an adverse event profile comparable to placebo.

3Phase 2 development for Chronic Spontaneous Urticaria (CSU) is planned to begin in the second half of 2026.

Septerna (SEPN) announced successful results from its Phase 1 clinical trial of SEP-631, an oral treatment targeting mast cell-driven diseases. The study demonstrated robust, dose-dependent inhibition of skin wheal formation, with complete inhibition achieved at doses as low as 10 mg once daily. Furthermore, the drug was well-tolerated across all dosage levels, showing a safety profile comparable to the placebo group. These positive findings significantly reduce clinical risk and pave the way for mid-stage development. The company plans to initiate Phase 2 trials for Chronic Spontaneous Urticaria (CSU) in the second half of 2026. This milestone is expected to bolster investor confidence in Septerna's clinical pipeline and overall market valuation.