Major Depressive Disorder (MDD)Phase 2NCT07065240
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)
A Phase 2 study testing SPT-300 in people with Major Depressive Disorder (MDD) and Major Depressive Disorder With Anxious Distress, run by Seaport Therapeutics at 61 sites in 7 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Major Depressive Disorder (MDD), Major Depressive Disorder With Anxious Distress
- What is being tested?
- SPT-300
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 360 participants
- Where
- 61 sitesin 7 countries
- Study dates
- 19 Jun 2025to Mar 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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 join
- 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.
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- 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.
- Previous history of intolerance or significant adverse effects, including drug allergy to allopregnanolone or any components of the SPT-300/placebo formulation.
- 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.
Trial locations and contacts
61 sites in 7 countries. Contact the study team or a site near you to ask about taking part.
61 sites in 7 countries
United States29 sites, 27 recruiting
- Recruiting
Seaport Investigator Site
Allentown, Pennsylvania, 18104
- Recruiting
Seaport Investigator Site
Atlanta, Georgia, 30328
- Recruiting
Seaport Investigator Site
Boston, Massachusetts, 02116
- Withdrawn
Seaport Investigator Site
Boston, Massachusetts, 02131
- Recruiting
Seaport Investigator Site
Brooklyn, New York, 11235
- Recruiting
Seaport Investigator Site
Cedarhurst, New York, 11516
- Recruiting
Seaport Investigator Site
Chino, California, 91710
- Recruiting
Seaport Investigator Site
Cromwell, Connecticut, 06416
- Recruiting
Seaport Investigator Site
Dallas, Texas, 75231
- Recruiting
Seaport Investigator Site
Decatur, Georgia, 30030
- Recruiting
Seaport Investigator Site
Everett, Washington, 98201
- Recruiting
Seaport Investigator Site
Garden Grove, California, 92845-2506
- Recruiting
Seaport Investigator Site
Glendale, California, 91206
- Recruiting
Seaport Investigator Site
Independence, Ohio, 44131
- Recruiting
Seaport Investigator Site
Irving, Texas, 75062
- Recruiting
Seaport Investigator Site
Jacksonville, Florida, 32256
- Recruiting
Seaport Investigator Site
Lauderhill, Florida, 33319
- Withdrawn
Seaport Investigator Site
Marietta, Georgia, 30060
- Recruiting
Seaport Investigator Site
New York, New York, 10029
- Recruiting
Seaport Investigator Site
North Canton, Ohio, 44720
- Recruiting
Seaport Investigator Site
Orlando, Florida, 32801
- Recruiting
Seaport Investigator Site
Palm Bay, Florida, 32905
- Recruiting
Seaport Investigator Site
Redlands, California, 92373
- Recruiting
Seaport Investigator Site
Richardson, Texas, 75080
- Recruiting
Seaport Investigator Site
Russells Mills, Massachusetts, 02747
- Recruiting
Seaport Investigator Site
San Jose, California, 95124
- Recruiting
Seaport Investigator Site
St Louis, Missouri, 63141
- Recruiting
Seaport Investigator Site
Staten Island, New York, 10314
- Recruiting
Seaport Investigator Site
West Palm Beach, Florida, 33407
Poland12 sites, 10 recruiting
- Recruiting
Seaport Investigator Site
Bełchatów, 97-400
- Recruiting
Seaport Investigator Site
Bialystok, 15-404
- Recruiting
Seaport Investigator Site
Bialystok, 15-464
- Recruiting
Seaport Investigator Site
Bydgoszcz, 85-080
- Recruiting
Seaport Investigator Site
Gdansk, 80-438
- Recruiting
Seaport Investigator Site
Katowice, 40-600
- Recruiting
Seaport Investigator Site
Leszno, 64-100
- Recruiting
Seaport Investigator Site
Poznan, 60-744
- Withdrawn
Seaport Investigator Site
Torun, 87-100
- Recruiting
Seaport Investigator Site
Tuszyn, 95-080
- Recruiting
Seaport Investigator Site
Warsaw, 00-124
- Withdrawn
Seaport Investigator Site
Wroclaw, 54-617
Czechia6 sites, 6 recruiting
- Recruiting
Seaport Investigator Site
Brno, 602 00
- Recruiting
Seaport Investigator Site
Pilsen, 301 00
- Recruiting
Seaport Investigator Site
Prague, 100 00
- Recruiting
Seaport Investigator Site
Prague, 110 00
- Recruiting
Seaport Investigator Site
Prague, 160 00
- Recruiting
Seaport Investigator Site
Prague, 186 00
Bulgaria4 sites, 3 recruiting
- Recruiting
Seaport Investigator Site
Lovech, 5500
- Recruiting
Seaport Investigator Site
Plovdiv, 4004
- Recruiting
Seaport Investigator Site
Sofia, 1000
- Withdrawn
Seaport Investigator Site
Sofia, 1680
Germany4 sites, 4 recruiting
- Recruiting
Seaport Investigator Site
Bad Homburg, 61348
- Recruiting
Seaport Investigator Site
Berlin, Brandenburg, D-10629
- Recruiting
Seaport Investigator Site
Chemnitz, 09111
- Recruiting
Seaport Investigator Site
Schwerin, Mecklenburg-Vorpommern, 19053
Hungary3 sites, 3 recruiting
- Recruiting
Seaport Investigator Site
Budapest, 1033
- Recruiting
Seaport Investigator Site
Budapest, 1083
- Recruiting
Seaport Investigator Site
Budapest, 1134
Slovakia3 sites, 2 recruiting
- Withdrawn
Seaport Investigator Site
Bratislava, 82007
- Recruiting
Seaport Investigator Site
Rimavská Sobota, 979 01
- Recruiting
Seaport Investigator Site
Vranov nad Topľou, 09301
About this study
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
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.
- Being tested
- SPT-300, Placebo
- Keywords
- Major Depressive Disorder, Depressive Disorder, Depression, Anxiety, Mood Disorders, BUOY-1 Study, SPT-300, LYT-300, GlyphAllo, Glyph Allopregnanolone
- Medical subject headings
- Depressive Disorder, Major, Depressive Disorder, Depression, Anxiety Disorders, Mood Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SPT-300Drug
Also called LYT-300, GlyphAllo, Glyph Allopregnanolone
A prodrug of allopregnanolone, a small molecule drug
PlaceboDrug
Placebo for SPT-300
| Study group | Role | What they receive |
|---|---|---|
| SPT-300 | Experimental | Participants will receive SPT-300 capsules once daily for 42 days Receives: Drug: SPT-300 |
| Placebo | Placebo comparator | Participants will receive matching placebo once daily for 42 days Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline to Day 42 in Hamilton Depression Rating Scale-17 (HAM-D-17) Total Score
HAM-D-17 is a 17-item, clinician-administered rating scale to assess the severity of symptoms in participants diagnosed with depression. The HAM-D-17 comprises individual ratings related to the following symptoms: depressed mood (sadness, hopeless, helpless, worthless), feelings of guilt, suicide, insomnia (early, middle, late), work and activities, retardation (slowness of thought and speech; impaired ability to concentrate; decreased motor activity), agitation, anxiety (psychic and somatic), somatic symptoms (gastrointestinal and general), genital symptoms, hypochondriasis, loss of weight, and insight. HAM-D Total Scores range from 0 to 52, with higher scores indicating more severe depression.
Measured: Baseline (Day 0) to Day 42
Secondary outcomes (1)
Change From Baseline to Day 42 in Clinical Global Impression - Severity (CGI-S)
The CGI-S is a clinician-administered rating scale to assess the severity of the participant's illness at the time of the assessment relative to the clinician's past experience with patients who have the same diagnosis. Scores range from 1 to 7, with higher scores indicating more severe illness.
Measured: Baseline (Day 0) to Day 42
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2025
- Study start19 Jun 2025
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Major Depressive Disorder (MDD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 360 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Seaport Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Premier Research
- Responsible party
- Sponsor
- Investigators
- David Walling, Ph.D., Principal investigator, Collaborative Neuroscience Research - Garden Grove
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07065240
- Sponsor's protocol ID
- SPT-300-2024-203
- Other IDs
- 2025-521240-37-00, 2025
- Status last verified
- Sep 2026
- First submitted
- 3 Jul 2025
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT07065240
- Acronym / sponsor ID
- SPT-300-2024-203
- Keywords
- Major Depressive Disorder, Depressive Disorder, Depression, Anxiety, Mood Disorders, BUOY-1 Study, SPT-300, LYT-300
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 360 participants (estimated)
- Lead sponsor
- Seaport TherapeuticsIndustry (pharma, biotech, devices)
- Collaborators
- Premier Research
- Study start
- 19 Jun 2025 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 15 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SPT-300 | Experimental | Drug: SPT-300Participants will receive SPT-300 capsules once daily for 42 days |
| Placebo | Placebo comparator | Drug: PlaceboParticipants will receive matching placebo once daily for 42 days |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (14 listed)
- History of, or current presentation consistent with:
- 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.
- Previous history of intolerance or significant adverse effects, including drug allergy to allopregnanolone or any components of the SPT-300/placebo formulation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SPT-300Also: LYT-300, GlyphAllo, Glyph AllopregnanoloneA prodrug of allopregnanolone, a small molecule drug | Drug | SPT-300 |
| PlaceboPlacebo for SPT-300 | Drug | Placebo |
Primary outcome
Change From Baseline to Day 42 in Hamilton Depression Rating Scale-17 (HAM-D-17) Total Score
Time frame: Baseline (Day 0) to Day 42
HAM-D-17 is a 17-item, clinician-administered rating scale to assess the severity of symptoms in participants diagnosed with depression. The HAM-D-17 comprises individual ratings related to the following symptoms: depressed mood (sadness, hopeless, helpless, worthless), feelings of guilt, suicide, insomnia (early, middle, late), work and activities, retardation (slowness of thought and speech; impaired ability to concentrate; decreased motor activity), agitation, anxiety (psychic and somatic), somatic symptoms (gastrointestinal and general), genital symptoms, hypochondriasis, loss of weight, and insight. HAM-D Total Scores range from 0 to 52, with higher scores indicating more severe depression.
1 secondary outcome
Change From Baseline to Day 42 in Clinical Global Impression - Severity (CGI-S)
Time frame: Baseline (Day 0) to Day 42
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David Walling, Ph.D. principal investigator
Collaborative Neuroscience Research - Garden Grove
61 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing SPT-300 in people with Major Depressive Disorder (MDD) and Major Depressive Disorder With Anxious Distress, run by Seaport Therapeutics at 61 sites in 7 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 61 sites in United States, Poland, Czechia, Bulgaria, Germany and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical trial information desk (617-807-4062, clinicaltrials@seaporttx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline to Day 42 in Hamilton Depression Rating Scale-17 (HAM-D-17) Total Score (time frame: Baseline (Day 0) to Day 42). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Oct 2026.