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AI brief of an SEC Form 8-K · Septerna, Inc. (SEPN)

Septerna selects SEP-204 as development candidate for Graves' disease and thyroid eye disease

Neutral Impact 3 of 5 product/contract Written later

Septerna, Inc. (Nasdaq: SEPN) said it selected SEP-204, an oral small molecule TSHR negative allosteric modulator, as a development candidate for Graves' disease and thyroid eye disease, and reported preclinical data ahead of a November 5, 2026 poster presentation at the American Thyroid Association meeting. The company plans to start a Phase 1 trial in healthy volunteers in the first quarter of 2027, but the filing reports no financial results or funding figures.

Key points

  • SEP-204 is designed for once-daily oral dosing, with a projected human half-life of approximately 20-40 hours.
  • Preclinical data showed selectivity of more than 1000-fold for TSHR over the related FSHR and LHR receptors.
  • In 28-day GLP toxicology studies in rats and dogs, SEP-204 was generally well tolerated.
  • Phase 1 trial initiation in healthy volunteers is planned for the first quarter of 2027.

The filing

CompanySepterna, Inc. (SEPN)
Form8-K, current report
Filed with the SECNov 4, 2026, 8:15 AM ET
Accession number0001193125-26-446260

Items reported: 7.01 Regulation FD Disclosure

Read the filing on SEC.gov ↗

Written by AI on Nov 9, 2026, 11:46 AM ET, from this filing only. Written later: this filing was briefed after the fact, when past filings were added to the site, so the brief may be read with hindsight; the filing itself is the record of what was known on November 04, 2026.

Briefs are written by AI from the filing text and can contain mistakes — open the filing before acting on anything. Impact (1-5) and tone are the AI's reading of the filing for shareholders, not a price forecast. Not investment advice.