Seaport Therapeutics, a clinical-stage biopharmaceutical company focused on developing innovative neuropsychiatric medicines, has successfully closed an oversubscribed $225 million Series B financing round. The round was led by General Atlantic, a prominent global growth investor, with participation from T. Rowe Price Associates, Foresite Capital, Invus, Goldman Sachs Alternatives, CPP Investments, and other new investors. Founding investors, including ARCH Venture Partners, Sofinnova Investments, Third Rock Ventures, and co-founder PureTech Health, also contributed to the round.
The recent financing brings Seaport Therapeutics’ total capital raised to $325 million since its launch in April 2024. The funds will be used to advance the company’s clinical-stage pipeline of first-in-class and best-in-class medicines and enhance the capabilities of the Glyph™ technology platform, which has shown clinical proof-of-concept.
“We are grateful for the support of our new and existing investors who share our mission to improve treatments for those suffering from depression, anxiety, and other neuropsychiatric disorders,” said Daphne Zohar, Founder and CEO of Seaport Therapeutics. “Our novel therapeutics have demonstrated clinical efficacy but were previously limited by challenges we can now overcome with our Glyph platform. This financing allows us to make significant progress toward delivering new medicines that can improve the lives of patients and their families.”
Brett Zbar, M.D., Managing Director and Global Head of Life Sciences at General Atlantic, expressed excitement about partnering with Seaport’s leadership team. “We are impressed by their strong CNS clinical track record, the Glyph platform, and the innovative pipeline. The team’s deep expertise in neuropsychiatry positions Seaport for unique advantages that will drive its success. We look forward to supporting the company’s next phase of development.”
Seaport’s pipeline programs leverage the Glyph platform, designed to enhance oral bioavailability, bypass first-pass metabolism, and reduce liver enzyme elevations and other side effects, enabling the advancement of clinically active drugs previously limited by these issues. The leading candidate, SPT-300, is an oral prodrug of allopregnanolone entering a Phase 2b study for major depressive disorder, potentially serving as a registration-enabling therapy. Allopregnanolone is an endogenous neurosteroid with clinically validated rapid anti-depressant and anxiolytic effects.
Steve Paul, M.D., Founder and Board Chair at Seaport, noted, “The development of new neuropsychiatric medicines often stalls due to poor drug-like properties or tolerability issues—challenges that our Glyph platform can address. For example, xanomeline faced tolerability hurdles, but once resolved, led to the FDA approval of Cobenfy™ for schizophrenia. We believe each of Seaport’s programs could similarly transform patient care.”
Additionally, SPT-320, a novel prodrug of agomelatine, is advancing into Phase 1 studies for generalized anxiety disorder (GAD) and could introduce the first new mechanism for GAD in decades. The Glyph platform allows it to bypass liver first-pass metabolism, potentially reducing the required dose and liver exposure, which may eliminate the need for liver function monitoring that previously hindered agomelatine’s development.
Seaport is also developing SPT-348, a prodrug of a non-hallucinogenic neuroplastogen aimed at treating mood and other neuropsychiatric disorders, which could become a first-in-class treatment. Beyond these programs, the company is actively pursuing multiple discovery and preclinical initiatives.
