secwatch.observer — SEC 8-K summary
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Issuer:     Septerna, Inc. (SEPN)
CIK:        0001984086
Form:       8-K
Filed at:   2025-08-21T23:59:59+00:00
Accession:  0001193125-25-184706
Event type: other_material
Sentiment:  neutral
Materiality: 0.50
Item codes: 7.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Septerna doses first participants in Phase 1 trial of SEP-631 for mast cell-driven diseases
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- SEP-631 is an oral small molecule MRGPRX2 negative allosteric modulator (NAM) targeting chronic spontaneous urticaria (CSU) and other mast cell-driven diseases.
- Phase 1 SAD/MAD trial will evaluate safety, tolerability, PK and PD in up to ~150 healthy volunteers; SAD dosing is underway.
- PD assessed via icatibant skin challenge in the MAD portion; no financial or guidance updates provided.
- Septerna highlights unmet need in CSU where many patients do not respond to antihistamines.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1984086/000119312525184706/0001193125-25-184706-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1984086/000119312525184706/d51455d8k.htm
  HTML page:      https://secwatch.observer/filing/0001193125-25-184706

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer