Seaport Therapeutics

Seaport Therapeutics is a Boston-based clinical-stage biopharmaceutical company developing oral medicines for depression, anxiety and other neuropsychiatric disorders. Its programs are built on the proprietary Glyph technology platform, which uses lymphatic transport to enhance oral bioavailability, bypass first-pass liver metabolism, and reduce hepatotoxicity, liver enzyme elevations and other side effects, with the aim of advancing drugs with clinically validated activity that were previously constrained by these pharmacokinetic limitations. The company states that the Glyph platform has demonstrated clinical proof-of-concept.

The pipeline comprises three disclosed lead candidates. GlyphAllo (SPT-300) is an oral prodrug of the endogenous neurosteroid allopregnanolone, targeted at major depressive disorder (with or without anxious distress); the company reports the candidate showed proof-of-concept in a validated clinical model of anxiety in healthy volunteers in a Phase 2a trial and has been advanced into a potentially registration-enabling Phase 2b study. GlyphAgo (SPT-320) is an oral prodrug of agomelatine for generalized anxiety disorder, designed to bypass first-pass metabolism so that efficacious systemic exposure can be achieved at a lower dose, reducing liver exposure and potentially removing the need for liver function monitoring; agomelatine is approved for GAD in Australia and for MDD in Australia and the EU but is not available in the U.S. Glyph2BLSD (SPT-348) is an oral prodrug of 2-bromo-LSD, a non-hallucinogenic neuroplastogen with reported 5-HT2A agonism and antidepressant-like preclinical effects, in development for multiple neuropsychiatric and headache indications. Additional discovery and preclinical programs are underway.

The company was launched in April 2024 by Daphne Zohar (Founder, CEO and board member; founder and former CEO of PureTech Health and co-founder of Karuna Therapeutics) and Steven M. Paul, M.D. (Founder and Board Chair; former CEO and Chair of Karuna Therapeutics and former President of Lilly Research Laboratories). Antony Loebel, M.D., formerly President and CEO of Sunovion Pharmaceuticals, serves as Chief Medical Officer and President of Clinical Development. Website news listings indicate the company priced an upsized initial public offering on 2026-04-30 and now reports quarterly financial results.

Founding story

The company was founded by Daphne Zohar and Steven M. Paul, M.D. Zohar founded PureTech Health and co-founded Karuna Therapeutics, where the team invented and advanced KarXT (later approved as Cobenfy); Paul previously led Karuna and Lilly Research Laboratories, where xanomeline's antipsychotic and procognitive properties were first demonstrated. Seaport applies a comparable strategy—identifying drugs with proven efficacy whose development was limited by delivery or tolerability problems and resolving those limitations—using the Glyph platform licensed from Monash University.

Business model

Seaport is a research and development-stage biopharmaceutical company; it does not report commercial products. It funds operations through equity financing (a $100M Series A, a $225M Series B, and a 2026 initial public offering per company and third-party sources) and, per one aggregator, a government grant, and develops proprietary drug candidates intended for regulatory approval and commercialization.

No revenue from marketed products is described in the sources; all disclosed candidates are in preclinical or clinical development.

Traction

Per the company website, GlyphAgo reported positive topline proof-of-concept results from an ongoing Phase 1 trial in healthy volunteers (announced 2026-04-02) and positive multiple-ascending dose data from that Phase 1 proof-of-concept trial (announced 2026-06-08). SPT-300/GlyphAllo previously demonstrated proof-of-concept in a validated clinical model of anxiety in healthy volunteers in a Phase 2a trial and, as of the Series B announcement, was being advanced into a potentially registration-enabling Phase 2b study in major depressive disorder. Total capital raised was reported at $325 million following the Series B; one aggregator reports $345 million across three rounds including a $15 million grant.

Latest developments

Website news entries dated 2026 report positive Phase 1 proof-of-concept topline results for GlyphAgo (2026-04-02), the addition of Dr. Sharon Mates to the board (2026-04-27), pricing of an upsized initial public offering (2026-04-30), positive multiple-ascending dose Phase 1 data for GlyphAgo and Q1 2026 financial results (both 2026-06-08), and Q2 2026 financial results (2026-08-03).