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Taking people in CzechiaPhase 2

Tests SPT-300 for depression in adults, with or without anxiety

Compares SPT-300 with placebo in adults with major depressive disorder.

Key facts

Who runs it
Seaport Therapeutics
Where
Brno, Plzen 3, Prague, and Prague 10, CzechiaSee the 6 sitesAlso in 7 other countries, 53 sites
Registry title
A Study to Evaluate the Efficacy and Safety of SPT-300 (GlyphAllo) in Participants With Major Depressive Disorder, With or Without Anxious Distress (BUOY-1 Study)
Status
Recruiting
Phase
Phase 2
People taking part
360 people, planned
Started
19 Jun 2025
Expected to end
Mar 2027
Type of study
Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • SPT-300
  • Placebo
Record updated
10 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults aged 18 to 65 whose main diagnosis is major depressive disorder, with or without anxious distress. They take SPT-300 or a placebo.

Age
18 to 65 years
Sex
All sexes can join.
Disease stage
Main diagnosis of major depressive disorder. The current depressive episode has lasted at least 4 weeks but no more than 18 months. Some other anxiety disorders are allowed if they are not the focus of treatment.
Earlier treatment
People with 2 or more failed treatments of adequate dose and duration in the current depressive episode cannot join.

Main reasons for not taking part

  • Depression with psychotic or catatonic features, bipolar disorder, schizophrenia or other psychotic disorder
  • Obsessive-compulsive disorder or any persistent neurocognitive disorder
  • Psychiatric hospitalization during the current depressive episode
  • History of drug or alcohol use disorder, or a positive test for cannabinoids
  • Clinically significant risk of suicide or harm to self or others

The registry criteria, word for word

Show all 14 criteriaShow less

Who can take part

  • Participant is a male or female between 18 and 65 years of age, inclusive willing and able and have capacity to provide written informed consent
  • Participants must have a primary diagnosis of MDD. Participants with a diagnosis of comorbid generalized anxiety disorder, social anxiety disorder, or panic disorder (with or without agoraphobia) may be included if not the focus of treatment over the past 6 months prior to Screening and the Investigator considers MDD to be the primary diagnosis at Screening and Baseline
  • Eligible participants must have a current depressive episode of at least 4 weeks, but no greater than 18 months in duration prior to Screening
  • Women of childbearing potential (WOCP) must not plan to become pregnant during the course of the study or be currently breastfeeding. WOCP agree to use an acceptable form of highly effective contraception during participation in the study and for 30 days after receiving the last dose of study treatment
  • Body mass index (BMI) between 18 to 40 kg/m2, inclusive
  • Participant is willing and able to refrain from the use of drugs of abuse

Who cannot take part

  • Previous history of intolerance or significant adverse effects, including drug allergy to allopregnanolone or any components of the SPT-300/placebo formulation
  • History of, or current presentation consistent with:; any depressive episode with psychotic or catatonic features; any bipolar manic, hypomanic or mixed episode, and substance-induced (e.g., antidepressant-induced) manic, hypomanic/mixed episode; bipolar disorder, including history of bipolar depression, or current presentation consistent with bipolar depression; schizophrenia, schizoaffective, or other psychotic disorder; obsessive-compulsive disorder; any persistent neurocognitive disorder
  • History of treatment-resistant depression defined as 2 or more failed treatments of adequate dose and duration in the current depressive episode
  • Psychiatric hospitalization within current depressive episode
  • Evidence or history of clinically significant diseases which can affect the patients' participation
  • Participant has a history of drug or alcohol use disorder
  • Participants with a positive test for cannabinoids
  • Clinically significant risk of suicide or harm to self or others

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 65 years old?

Where in Czechia

Also in 7 other countries, 53 sites

  • Medipa S R OBrno, CzechiaTaking people
  • A-Shine s.r.o.Plzen 3, CzechiaTaking people
  • INEP medical s.r.o.Prague, CzechiaTaking people
  • Medical Services Prague S R OPrague, CzechiaTaking people
  • Neuropsychiatrie Petrska s.r.o.Prague, CzechiaTaking people
  • Clintrial s.r.o.Prague 10, CzechiaTaking people

About the trial

What the trial wants to find out

This is a randomized, parallel-group, double-blind, placebo-controlled, monotherapy study to evaluate the efficacy, safety, and tolerability of SPT-300 (GlyphAllo) in adults with major depressive disorder (MDD), with or without anxious distress.

The 2 groups in the trial

  • SPT-300Treatment being tested

    Participants will receive SPT-300 capsules once daily for 42 days

  • PlaceboPlacebo, for comparison

    Participants will receive matching placebo once daily for 42 days

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Randomized, Parallel-Group, Double-Blind, Placebo-Controlled, Monotherapy Study of the Efficacy, Safety, and Tolerability of SPT-300 in Adults With Major Depressive Disorder (MDD), With or Without Anxious Distress
Plain-language title
Tests SPT-300 for depression in adults, with or without anxietyGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 11 November 2026.
Fit questions
Built from NCT07065240, who can take part
Record updated
10 November 2026