Seaport Therapeutics (Nasdaq: SPTX), a clinical-stage neuropsychiatric drug developer based in Boston, priced an upsized initial public offering of 14,160,000 shares at USD 18.00 per share, the top of the target range, raising gross proceeds of USD 254.9 million on the Nasdaq Global Select Market.
Underwriters received a 30-day option to purchase an additional 2,124,000 shares at the offering price, less underwriting discounts and commissions. The offering was expected to close on May 4, 2026, subject to customary closing conditions. The filing did not disclose pre- or post-offering ownership structure.
Seaport Therapeutics is developing oral prodrug therapies for major depressive disorder and generalized anxiety disorder using its proprietary Glyph platform, which is designed to bypass first-pass hepatic metabolism and increase oral bioavailability of clinically validated parent compounds. The lead asset, GlyphAllo (SPT-300), is an oral prodrug of allopregnanolone, a GABA-A receptor positive allosteric modulator, currently in Phase IIb development for major depressive disorder with or without anxious distress. The second asset, GlyphAgo (SPT-320), an oral prodrug of agomelatine, is in Phase II development for generalized anxiety disorder. A third asset, SPT-348, an oral prodrug of 2-bromo-LSD targeting treatment-resistant depression and post-traumatic stress disorder, remains in preclinical development.