New depression drug SPT-300 moves to safety testing in extension trial

NCT ID NCT07161700

ENROLLING_BY_INVITATION Symptom relief Sponsor: Seaport Therapeutics Source: ClinicalTrials.gov ↗

First seen Jun 24, 2026 · Last updated Jul 14, 2026 · Updated 3 times

Summary

This study is an extension of an earlier trial, testing the safety and tolerability of SPT-300 in 360 adults with major depressive disorder, with or without anxious distress. Participants who completed the prior study will receive SPT-300 for 6 weeks. The goal is to monitor side effects and see if the drug is safe enough for further development.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: SPT-300 (a prodrug of allopregnanolone)
What this could lead to: If successful, this could point toward a new treatment option for major depressive disorder that may ease symptoms with a different mechanism than current antidepressants.
What could go wrong: This is an early-phase, open-label extension study with no placebo group, so results may be biased. It focuses on safety, not effectiveness, and the drug may still fail in larger trials or cause side effects.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

anxiety disorder Depression depressive disorder major depressive disorder mood disorder

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

MAJOR DEPRESSIVE DISORDER (MDD) MAJOR DEPRESSIVE DISORDER WITH ANXIOUS DISTRESS

Contacts and locations

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Locations

Seaport Investigator Site

Chino, California, 91710, United States
Seaport Investigator Site

Garden Grove, California, 92845-2506, United States
Seaport Investigator Site

Glendale, California, 91206, United States
Seaport Investigator Site

West Palm Beach, Florida, 33407, United States
Seaport Investigator Site

Atlanta, Georgia, 30328, United States
Seaport Investigator Site

Decatur, Georgia, 30030, United States
Seaport Investigator Site

Boston, Massachusetts, 02116, United States
Seaport Investigator Site

St Louis, Missouri, 63141, United States
Seaport Investigator Site

Brooklyn, New York, 11235, United States
Seaport Investigator Site

New York, New York, 10029, United States
Seaport Investigator Site

Staten Island, New York, 10314, United States
Seaport Investigator Site

Independence, Ohio, 44131, United States
Seaport Investigator Site

North Canton, Ohio, 44720, United States
Seaport Investigator Site

Irving, Texas, 75062, United States
Seaport Investigator Site

Plovdiv, 4004, Bulgaria
Seaport Investigator Site

Sofia, 1000, Bulgaria
Seaport Investigator Site

Brno, 602 00, Czechia
Seaport Investigator Site

Prague, 100 00, Czechia
Seaport Investigator Site

Prague, 110 00, Czechia
Seaport Investigator Site

Prague, 160 00, Czechia
Seaport Investigator Site

Prague, 186 00, Czechia
Seaport Investigator Site

Schwerin, Mecklenburg-Vorpommern, 19053, Germany
Seaport Investigator Site

Chemnitz, 09111, Germany
Seaport Investigator Site

Bialystok, 15-404, Poland
Seaport Investigator Site

Bialystok, 15-464, Poland
Seaport Investigator Site

Bydgoszcz, 85-080, Poland
Seaport Investigator Site

Gdansk, 80-438, Poland
Seaport Investigator Site

Leszno, 64-100, Poland
Seaport Investigator Site

Poznan, 60-744, Poland
Seaport Investigator Site

Tuszyn, 95-080, Poland
Seaport Investigator Site

Rimavská Sobota, 979 01, Slovakia
Seaport Investigator Site

Vranov nad Topľou, 09301, Slovakia

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