Seaport Therapeutics reported a larger first-quarter 2026 loss while significantly strengthening its balance sheet and advancing its neuropsychiatry pipeline. Net loss was $25.4M, compared with $13.1M a year earlier, driven mainly by higher research and development spending of $21.4M as lead programs moved into later-stage trials.
Cash, cash equivalents, and investments totaled $212.6M as of March 31, 2026. In May, Seaport completed an upsized IPO generating gross proceeds of $260.0M, and now expects its current cash to fund operations into 2029. The company highlighted progress across its GlyphAllo and GlyphAgo programs, including a potentially registration-enabling Phase 2b MDD trial, new Phase 1 data supporting dose selection in GAD, and plans for multiple Phase 2 studies with topline readouts extending through 2028.
General Atlantic and affiliated funds filed a Schedule 13D disclosing beneficial ownership of 6,101,582 shares of Seaport Therapeutics common stock, representing 11.5% of the company. This stake reflects both pre‑IPO preferred holdings and new IPO purchases.
At the IPO closing, 10,526,315 shares of Series B convertible preferred stock held by General Atlantic (SP), L.P. automatically converted into 3,351,582 common shares, and GA SP purchased an additional 2,750,000 common shares at $18.00 per share. Multiple General Atlantic entities are treated as a coordinated “group” with shared voting and dispositive power over the position.
The filing states the investment is for general investment purposes but notes the group may engage with management and other shareholders and could increase, reduce, or hedge its position over time. GA SP is also party to a customary 180‑day IPO lock‑up, limiting sales and certain hedging transactions through late October 2026.
Seaport Therapeutics ownership filing: The Goldman Sachs Group, Inc. and Goldman Sachs & Co. LLC report beneficial ownership of 2,791,814 shares of Seaport Therapeutics Voting Common Stock, representing 5.5% of the class. The filing is a joint Schedule 13G filed in early May 2026 and identifies shared voting and dispositive power of 2,791,814 shares held by the reporting entities.
Seaport Therapeutics, Inc. filed an initial Form 3 showing that General Atlantic–affiliated funds hold 6,101,582 shares of its Common Stock. This amount includes 3,351,582 shares issuable upon conversion of Series B preferred stock. The holdings are reported as indirect, through multiple partnerships and investment vehicles described in the footnotes. A six-member Partnership Committee ultimately controls key general partners, and each member disclaims beneficial ownership of the shares except to the extent of any pecuniary interest.
ARCH Venture Fund XII and affiliated entities filed a Schedule 13D reporting beneficial ownership of 6,294,951 shares of Seaport Therapeutics, Inc. common stock, representing 11.9% of the outstanding shares. The position was built through preferred stock investments in 2024 that converted into common stock at the IPO, plus a purchase of 1,100,000 common shares at $18.00 per share on May 1, 2026. In total, AVF XII invested about $89,799,993.80 to acquire these securities. The shares are held for investment purposes, and the fund has registration rights and is subject to a 180-day lock-up period after April 30, 2026, limiting near-term sales without underwriter and issuer consent.
Zohar Daphne reported acquisition or exercise transactions in this Form 4 filing.
Seaport Therapeutics, Inc. reported that Chief Executive Officer Daphne Zohar received two stock option grants on April 30, 2026 for 1,486,786 and 271,813 options to buy common stock at $18.00 per share, expiring on April 29, 2036. The options vest in forty-eight equal monthly installments after April 30, 2026, conditioned on her continued service.
Seaport Therapeutics, Inc. reported that investment fund Sofinnova Venture Partners XI, L.P. converted its preferred stock into common shares in connection with the closing of the company’s initial public offering. The transactions are attributed to Sofinnova, not directly to director James Healy, who is a managing member of the fund’s general partner and disclaims beneficial ownership except for any pecuniary interest.
Sofinnova converted 2,526,315 shares of Series B Preferred Stock into 804,379 shares of common stock and 6,052,631 shares of Series A-2 Preferred Stock into 1,927,159 shares of common stock, based on a one-for-3.1407 conversion ratio. Following these conversions, Sofinnova directly holds 2,731,538 common shares of Seaport Therapeutics.
Seaport Therapeutics, Inc. director David E. Wheadon received a grant of stock options covering 12,258 shares of common stock. The options have an exercise price of $18.00 per share and expire on April 29, 2036. All 12,258 underlying shares vest in full on April 30, 2027, subject to his continued service, and this grant represents his entire reported option position in this filing.
Seaport Therapeutics director Sandra E. Peterson received a grant of stock options representing 12,258 shares of common stock. The options have an exercise price of $18.00 per share and expire on April 29, 2036. According to the footnote, all 12,258 underlying shares vest in full on April 30, 2027, subject to her continued service with the company.
Seaport Therapeutics Chief Scientific Officer Michael Cunyuan Chen reported equity-related acquisitions. On May 4, 2026, he acquired 3,351 shares of Common Stock through the conversion of 10,526 shares of Series B Preferred Stock, which automatically converted in connection with the company’s initial public offering on a one-for-3.1407 basis.
After this conversion, he directly held 3,351 common shares. Separately, on April 30, 2026, he received a grant of stock options for 63,680 shares of Common Stock at an exercise price of $18.00 per share, expiring on April 29, 2036. These options vest in 48 equal monthly installments following April 30, 2026, subject to his continued service.