Seaport Therapeutics Q3 2026 Results & Clinical Progress

BOSTON, USA - Seaport Therapeutics, Inc. (Nasdaq: SPTX), a clinical-stage therapeutics company, announced its financial results for the third quarter of 2026, alongside significant corporate and clinical advancements. The company highlighted positive clinical milestones for its neuropsychiatric drug candidates, GlyphAllo and GlyphAgo, and reported a robust cash position expected to fund operations into 2029.

Daphne Zohar, Co-Founder and Chief Executive Officer, emphasized the company's progress, stating, "Over the last few months, Seaport met two key clinical milestones - we dosed the first patient in the Phase 2a proof-of-pharmacology trial of GlyphAgo in patients with GAD and sleep disturbance, and demonstrated that GlyphAllo did not impair next-morning driving performance in a Phase 1 driving trial." She noted that Seaport is now advancing two Phase 2 programs and is well-capitalized to pursue its mission of developing better medicines for mental illness.

Key Clinical Progress

GlyphAllo Program for Major Depressive Disorder (MDD):

• Positive Phase 1 Driving Simulation Data: Seaport announced positive topline data from a Phase 1 trial in healthy volunteers, demonstrating that evening dosing of GlyphAllo (375 mg) did not impair next-morning driving performance compared to placebo. A 250 mg dose also showed no impairment. The drug was well-tolerated.
• Phase 2b BUOY-1 Trial On Track: Enrollment is progressing as planned for the global, randomized, double-blind, placebo-controlled Phase 2b BUOY-1 trial in MDD patients. Topline data from this potentially registration-enabling trial are anticipated in the first half of 2027.

GlyphAgo Program for Generalized Anxiety Disorder (GAD):

• Phase 2a Proof-of-Pharmacology Trial Initiated: The first patient has been dosed in a Phase 2a trial evaluating GlyphAgo's effects on sleep and anxiety severity in GAD patients with sleep disturbance. Topline data are expected in early 2028.
• Planned Phase 2/3 Trial: Seaport plans to initiate a global, randomized, double-blind, placebo-controlled, potentially registration-enabling Phase 2/3 trial for GlyphAgo in GAD in the first half of 2027, with topline data expected by year-end 2028.
• Pharmacokinetic Data Presented: Detailed Phase 1 pharmacokinetic data showed dose-dependent increases in agomelatine exposure, no food effect, and no accumulation over seven days, reinforcing significantly increased bioavailability and reduced PK variability compared to unmodified agomelatine.

Preclinical Programs:

• Glyph2BLSD (SPT-348): The development of this non-hallucinogenic neuroplastogen for neuropsychiatric and headache disorders is on track, with first-in-human-enabling studies expected to be completed by year-end 2027.

Third Quarter 2026 Financial Highlights

Financial Overview:

• Cash Position: As of September 30, 2026, cash, cash equivalents, and investments totaled 403.8 million USD. This is expected to fund operations into 2029, covering three upcoming mid-to-late-stage clinical data readouts.
• R&D Expenses: Research and development expenses increased to 23.9 million USD for Q3 2026, up from 20.5 million USD in Q3 2025, primarily due to the advancement of the GlyphAllo Phase 2b BUOY-1 trial.
• G&A Expenses: General and administrative expenses rose to 6.5 million USD for Q3 2026, compared to 5.0 million USD in Q3 2025, mainly due to increased costs associated with operating as a public company.
• Net Loss: The net loss for Q3 2026 was 26.4 million USD, compared to a net loss of 22.5 million USD for Q3 2025.