Actively Recruiting
A Randomized, Double-Blind, Placebo-Controlled Study of SPT-300 for Adults With Major Depressive Disorder, With or Without Anxious Distress
Led by Seaport Therapeutics · Updated on 2026-05-19
360
Participants Needed
59
Research Sites
N/A
Total Duration
On this page
Sponsors
S
Seaport Therapeutics
Lead Sponsor
P
Premier Research
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are studying the effects of SPT-300 (GlyphAllo), a prodrug of allopregnanolone, in adults with major depressive disorder (MDD), including those with or without anxious distress. This randomized, double-blind, placebo-controlled study aims to evaluate the drug's efficacy, safety, and tolerability in this population. The study is a Phase 2 trial designed to provide important information about SPT-300 as a monotherapy treatment for MDD. Participants will be randomly assigned to receive either SPT-300 capsules or a matching placebo once daily for 42 days. This parallel-group design ensures that both groups are treated similarly except for the active drug, allowing researchers to compare the effects accurately. The study focuses solely on monotherapy, meaning no additional antidepressant treatments are given during this period. During the trial, participants will be assessed at the start and after 42 days of treatment using the Hamilton Depression Rating Scale-17 (HAM-D-17) to measure changes in depression severity. Safety and tolerability will also be monitored throughout the study. Additional evaluations include the Clinical Global Impression - Severity (CGI-S) scale to assess overall illness severity. The total participation time corresponds to the 42-day treatment period, with monitoring to ensure adherence and safety.
CONDITIONS
Brief 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)
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Participant is male or female between 18 and 65 years old and able to provide written informed consent
- Primary diagnosis of major depressive disorder (MDD), with or without anxious distress
- Current depressive episode lasting at least 4 weeks and no more than 18 months before screening
- Women of childbearing potential must not plan pregnancy or be breastfeeding and agree to use effective contraception during and 30 days after the study
- Body mass index (BMI) between 18 and 40 kg/m2
- Willing and able to refrain from using drugs of abuse
You will not qualify if you...
- History or current presentation of depressive episode with psychotic or catatonic features
- History or current bipolar manic, hypomanic, or mixed episodes, including substance-induced episodes
- Bipolar disorder or bipolar depression
- Schizophrenia, schizoaffective, or other psychotic disorders
- Obsessive-compulsive disorder
- Persistent neurocognitive disorders
- Treatment-resistant depression with 2 or more failed treatments in the current episode
- Psychiatric hospitalization during current depressive episode
- Clinically significant diseases affecting participation
- History of intolerance or allergic reaction to allopregnanolone or study drug components
- History of drug or alcohol use disorder
- Positive test for cannabinoids
- Clinically significant risk of suicide or harm to self or others
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 42 days
Participants receive SPT-300 or placebo capsules once daily to evaluate the efficacy and safety for major depressive disorder.
Multiple visits during treatment period
Trial Site Locations
Total: 59 locations
1
Seaport Investigator Site
Chino, California, United States, 91710
Actively Recruiting
2
Seaport Investigator Site
Garden Grove, California, United States, 92845-2506
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3
Seaport Investigator Site
Glendale, California, United States, 91206
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4
Seaport Investigator Site
San Jose, California, United States, 95124
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5
Seaport Investigator Site
Cromwell, Connecticut, United States, 06416
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6
Seaport Investigator Site
Jacksonville, Florida, United States, 32256
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7
Seaport Investigator Site
Lauderhill, Florida, United States, 33319
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8
Seaport Investigator Site
Orlando, Florida, United States, 32801
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9
Seaport Investigator Site
Palm Bay, Florida, United States, 32905
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10
Seaport Investigator Site
West Palm Beach, Florida, United States, 33407
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11
Seaport Investigator Site
Atlanta, Georgia, United States, 30328
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12
Seaport Investigator Site
Decatur, Georgia, United States, 30030
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13
Seaport Investigator Site
Marietta, Georgia, United States, 30060
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14
Seaport Investigator Site
Boston, Massachusetts, United States, 02116
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15
Seaport Investigator Site
Boston, Massachusetts, United States, 02131
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16
Seaport Investigator Site
Russells Mills, Massachusetts, United States, 02747
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17
Seaport Investigator Site
St Louis, Missouri, United States, 63141
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18
Seaport Investigator Site
Brooklyn, New York, United States, 11235
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19
Seaport Investigator Site
Cedarhurst, New York, United States, 11516
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20
Seaport Investigator Site
New York, New York, United States, 10029
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21
Seaport Investigator Site
Staten Island, New York, United States, 10314
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22
Seaport Investigator Site
Independence, Ohio, United States, 44131
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23
Seaport Investigator Site
North Canton, Ohio, United States, 44720
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24
Seaport Investigator Site
Allentown, Pennsylvania, United States, 18104
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25
Seaport Investigator Site
Dallas, Texas, United States, 75231
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26
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Irving, Texas, United States, 75062
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27
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Richardson, Texas, United States, 75080
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28
Seaport Investigator Site
Everett, Washington, United States, 98201
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29
Seaport Investigator Site
Plovdiv, Bulgaria, 4004
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30
Seaport Investigator Site
Sofia, Bulgaria, 1000
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31
Seaport Investigator Site
Sofia, Bulgaria, 1680
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32
Seaport Investigator Site
Brno, Czechia, 602 00
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33
Seaport Investigator Site
Pilsen, Czechia, 301 00
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34
Seaport Investigator Site
Prague, Czechia, 100 00
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35
Seaport Investigator Site
Prague, Czechia, 110 00
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36
Seaport Investigator Site
Prague, Czechia, 160 00
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37
Seaport Investigator Site
Prague, Czechia, 186 00
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38
Seaport Investigator Site
Berlin, Brandenburg, Germany, D-10629
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39
Seaport Investigator Site
Schwerin, Mecklenburg-Vorpommern, Germany, 19053
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40
Seaport Investigator Site
Bad Homburg, Germany, 61348
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41
Seaport Investigator Site
Chemnitz, Germany, 09111
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42
Seaport Investigator Site
Budapest, Hungary, 1033
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43
Seaport Investigator Site
Budapest, Hungary, 1083
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44
Seaport Investigator Site
Budapest, Hungary, 1134
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45
Seaport Investigator Site
Bełchatów, Poland, 97-400
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46
Seaport Investigator Site
Bialystok, Poland, 15-404
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47
Seaport Investigator Site
Bialystok, Poland, 15-464
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48
Seaport Investigator Site
Bydgoszcz, Poland, 85-080
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49
Seaport Investigator Site
Gdansk, Poland, 80-438
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50
Seaport Investigator Site
Katowice, Poland, 40-600
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51
Seaport Investigator Site
Leszno, Poland, 64-100
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52
Seaport Investigator Site
Poznan, Poland, 60-744
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53
Seaport Investigator Site
Torun, Poland, 87-100
Withdrawn
54
Seaport Investigator Site
Tuszyn, Poland, 95-080
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55
Seaport Investigator Site
Warsaw, Poland, 00-124
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56
Seaport Investigator Site
Wroclaw, Poland, 54-617
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57
Seaport Investigator Site
Bratislava, Slovakia, 82007
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58
Seaport Investigator Site
Rimavská Sobota, Slovakia, 979 01
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59
Seaport Investigator Site
Vranov nad Topľou, Slovakia, 09301
Actively Recruiting
Research Team
C
Clinical trial information desk
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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