Boston — Seaport Therapeutics, Inc., a clinical-stage therapeutics company developing neuropsychiatric medicines, reported positive topline results from a Phase 1 driving simulation trial of GlyphAllo, also known as SPT-300, in healthy volunteers.
The study met its primary endpoint, showing that evening dosing of 375 mg GlyphAllo did not impair next-morning driving performance compared with placebo on Day 5 following multiple-day dosing. A key secondary endpoint was also met, with a single 250 mg dose showing no next-morning driving impairment compared with placebo on Day 2.
GlyphAllo is an oral prodrug of allopregnanolone being developed as a potential treatment for major depressive disorder.
“We are very pleased by the results which showed no next-morning driving impairment at either dose evaluated. The trial used a validated driving simulator and trial design with an evening dosing regimen consistent with the Phase 2b BUOY-1 trial and GlyphAllo’s intended clinical use,” said Daphne Zohar, Co-founder and Chief Executive Officer of Seaport Therapeutics. “We believe that GlyphAllo has the potential to deliver the benefits of allopregnanolone without next-morning effects on driving. These results further reinforce our view that GlyphAllo offers meaningful differentiation as we advance it as a potential first-in-class treatment for major depressive disorder.”
The trial also included a 7.5 mg dose of zopiclone as a positive control. Zopiclone produced statistically significant impairment compared with both GlyphAllo and placebo on Days 2 and 5, which the company said confirmed the study’s ability to detect effects on driving performance.
GlyphAllo was well tolerated at all doses, with most adverse events reported as mild and transient. No serious adverse events were reported.
Seaport plans to submit the results to the U.S. Food and Drug Administration as part of GlyphAllo’s ongoing development program and present additional analyses at scientific meetings.
The company is also enrolling patients in BUOY-1, a global, randomized, double-blind, placebo-controlled Phase 2b trial evaluating GlyphAllo in patients with major depressive disorder, with or without anxious distress.
Seaport expects topline results from BUOY-1 in the first half of 2027.
