BOSTON — October 7, 2026
Seaport Therapeutics (Nasdaq: SPTX), a clinical-stage therapeutics company developing medicines for neuropsychiatric disorders, announced that the first patient has been dosed in a Phase 2a clinical trial of GlyphAgo™ (SPT-320) in adults with generalized anxiety disorder (GAD) and sleep disturbance. Conducted in Australia, the six-week trial is designed to establish proof of pharmacology by assessing the investigational oral prodrug’s effects on sleep and anxiety symptoms. Seaport expects to report topline results in early 2028. PureTech Health plc, which founded Seaport Therapeutics, also announced the milestone.
Study Evaluates Sleep, Anxiety and Treatment Safety
The randomized, double-blind Phase 2a study is evaluating two daily dose levels of GlyphAgo: 16 mg and 32 mg, corresponding to approximately 5 mg and 10 mg of agomelatine, respectively. The primary focus is to assess sleep outcomes using patient-reported measures, including the Insomnia Severity Index (ISI), and electroencephalography-based measures of sleep architecture. Additional assessments include anxiety severity using the Hamilton Anxiety Scale, overall illness severity, safety, tolerability and pharmacokinetics. The study aims to determine whether GlyphAgo can deliver relevant pharmacological effects in patients with GAD who also experience sleep disturbance
Phase 1 Data Support GlyphAgo’s Delivery Approach
GlyphAgo is a Glyphed oral prodrug of agomelatine developed using Seaport’s proprietary Glyph™ platform. The approach is designed to promote absorption through the intestinal lymphatic system, bypassing first-pass liver metabolism and potentially improving drug bioavailability while reducing liver exposure. In a Phase 1 study in healthy volunteers, GlyphAgo demonstrated a 6.8-fold increase in bioavailability compared with unmodified agomelatine. The company also reported therapeutically relevant agomelatine exposure at the selected dose levels, lower variability in drug exposure and no serious or severe adverse events or liver-related adverse events during the reported seven-day dosing period. These early findings require further evaluation in clinical studies.
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Seaport Plans Broader Phase 2/3 Development
Seaport plans to initiate a global, randomized, double-blind, placebo-controlled Phase 2/3 trial evaluating GlyphAgo in patients with GAD during the first half of 2027, with topline results expected by the end of 2028. Agomelatine acts as an MT1/MT2 melatonin receptor agonist and a serotonin 5-HT2C receptor antagonist and has previously been studied for anxiety and sleep-related effects. However, GlyphAgo remains investigational, and its efficacy and safety in GAD have not yet been established. The ongoing clinical program will assess whether the platform’s drug-delivery approach can help address limitations associated with conventional agomelatine, including low bioavailability and concerns about liver exposure.
Source::Seaport Therapeutics, press release
