Major Depressive Disorder (MDD)Phase 2NCT07161700
An Open-Label Extension Study to Evaluate the Safety and Tolerability of SPT-300 (GlyphAllo) in Participants With Major Depressive Disorder, With or Without Anxious Distress (BUOY-1 OLE 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 42 sites in 7 countries.
Trial summary
This is an open-label, monotherapy, extension study to evaluate the 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 66 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?
- No, everyone receives an active treatment
- How many people
- 360 participants
- Where
- 42 sitesin 7 countries
- Study dates
- 2 Sep 2025to May 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 66 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participant who completed treatment in Study SPT-300-2024-203 (i.e., participant who competed Visit 8 [Day 42] of Study SPT-300-2024-203 [BUOY-1 Study]).
- Women of childbearing potential (WOCP) must not plan to become pregnant during the course of the study or be currently breastfeeding. WOCP must agree to use a highly effective form of contraception during participation in the study and for 30 days after receiving the last dose of study treatment.
- Participant is willing and able to refrain from the use of drugs of abuse.
Who cannot join
- Participants who, in the opinion of the Investigator, medical monitor, or Sponsor, should not participate in the study.
- Participants who, in the judgment of the Investigator, were noncompliant with trial procedures or with study treatment administration during the double-blind study (BUOY-1 Study).
- Female participants with a positive urine pregnancy test result. Female participants may be enrolled without a negative urine test if they are surgically sterile or at least 2 years post-menopause.
Trial locations and contacts
42 sites in 7 countries. Contact the study team or a site near you to ask about taking part.
42 sites in 7 countries
United States20 sites
Seaport Investigator Site
Atlanta, Georgia, 30328
Seaport Investigator Site
Boston, Massachusetts, 02116
Seaport Investigator Site
Brooklyn, New York, 11235
Seaport Investigator Site
Cedarhurst, New York, 11516
Seaport Investigator Site
Chino, California, 91710
Seaport Investigator Site
Cromwell, Connecticut, 06416
Seaport Investigator Site
Decatur, Georgia, 30030
Seaport Investigator Site
Garden Grove, California, 92845-2506
Seaport Investigator Site
Glendale, California, 91206
Seaport Investigator Site
Independence, Ohio, 44131
Seaport Investigator Site
Irving, Texas, 75062
Seaport Investigator Site
Lauderhill, Florida, 33319
Seaport Investigator Site
New York, New York, 10029
Seaport Investigator Site
North Canton, Ohio, 44720
Seaport Investigator Site
Palm Bay, Florida, 32905
Seaport Investigator Site
Richardson, Texas, 75080
Seaport Investigator Site
San Jose, California, 95124
Seaport Investigator Site
St Louis, Missouri, 63141
Seaport Investigator Site
Staten Island, New York, 10314
Seaport Investigator Site
West Palm Beach, Florida, 33407
Poland7 sites
Seaport Investigator Site
Bialystok, 15-404
Seaport Investigator Site
Bialystok, 15-464
Seaport Investigator Site
Bydgoszcz, 85-080
Seaport Investigator Site
Gdansk, 80-438
Seaport Investigator Site
Leszno, 64-100
Seaport Investigator Site
Poznan, 60-744
Seaport Investigator Site
Tuszyn, 95-080
Czechia5 sites
Seaport Investigator Site
Brno, 602 00
Seaport Investigator Site
Prague, 100 00
Seaport Investigator Site
Prague, 110 00
Seaport Investigator Site
Prague, 160 00
Seaport Investigator Site
Prague, 186 00
Germany4 sites
Seaport Investigator Site
Bad Homburg, 61348
Seaport Investigator Site
Berlin, Brandenburg, D-10629
Seaport Investigator Site
Chemnitz, 09111
Seaport Investigator Site
Schwerin, Mecklenburg-Vorpommern, 19053
Bulgaria2 sites
Seaport Investigator Site
Plovdiv, 4004
Seaport Investigator Site
Sofia, 1000
Hungary2 sites
Seaport Investigator Site
Budapest, 1033
Seaport Investigator Site
Budapest, 1134
Slovakia2 sites
Seaport Investigator Site
Rimavská Sobota, 979 01
Seaport Investigator Site
Vranov nad Topľou, 09301
About this study
Official title: A 6-Week, Multicenter, Open-Label, Monotherapy, Extension Study of SPT-300 in Adults With Major Depressive Disorder, With or Without Anxious Distress
This is an open-label, monotherapy, extension study to evaluate the safety and tolerability of SPT-300 (GlyphAllo) in adults with major depressive disorder (MDD), with or without anxious distress.
- Being tested
- SPT-300
- Keywords
- Major Depressive Disorder, Depressive Disorder, Depression, Anxiety, Mood Disorders, SPT-300, LYT-300, GlyphAllo, Glyph Allopregnanolone, BUOY-1 OLE Study, Anxious Distress, Open Label Extension Study
- 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
| Study group | Role | What they receive |
|---|---|---|
| SPT-300 | Experimental | Participants will receive SPT-300 capsules once daily for 42 days Receives: Drug: SPT-300 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and tolerability assessments based on Treatment-emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs) and validated clinical scales and procedures
Adverse events (AEs) are monitored from Day 1 to 49. A TEAE is as any AE with an onset after first dose of study treatment up to Day 49. Clinically significant abnormalities in clinical laboratory evaluations, ECGs, vital signs, physical examinations and Columbia Suicide Severity Rating Scale (C-SSRS) will be reported as TEAEs.
Measured: Up to Day 49
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2025
- Study start2 Sep 2025
- Primary completionMay 2027 (estimated)
- Study completionMay 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- 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
- NCT07161700
- Sponsor's protocol ID
- SPT-300-2024-204
- Other IDs
- 2025-522347-18-00, 2025
- Status last verified
- Sep 2026
- First submitted
- 2 Sep 2025
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- 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 6-Week, Multicenter, Open-Label, Monotherapy, Extension Study of SPT-300 in Adults With Major Depressive Disorder, With or Without Anxious Distress
- ClinicalTrials.gov ID
- NCT07161700
- Acronym / sponsor ID
- SPT-300-2024-204
- Keywords
- Major Depressive Disorder, Depressive Disorder, Depression, Anxiety, Mood Disorders, SPT-300, LYT-300, GlyphAllo
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 360 participants (estimated)
- Lead sponsor
- Seaport TherapeuticsIndustry (pharma, biotech, devices)
- Collaborators
- Premier Research
- Study start
- 2 Sep 2025 (actual)
- Primary completion
- May 2027 (estimated)
- Study completion
- May 2027 (estimated)
- First posted
- 9 Sep 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 an open-label, monotherapy, extension study to evaluate the 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| SPT-300 | Experimental | Drug: SPT-300Participants will receive SPT-300 capsules once daily for 42 days |
Who may qualify
- Ages
- 18 to 66 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Participant who completed treatment in Study SPT-300-2024-203 (i.e., participant who competed Visit 8 [Day 42] of Study SPT-300-2024-203 [BUOY-1 Study]).
- Women of childbearing potential (WOCP) must not plan to become pregnant during the course of the study or be currently breastfeeding. WOCP must agree to use a highly effective form of contraception during participation in the study and for 30 days after receiving the last dose of study treatment.
- Participant is willing and able to refrain from the use of drugs of abuse.
Key exclusion criteria (3 listed)
- Participants who, in the opinion of the Investigator, medical monitor, or Sponsor, should not participate in the study.
- Participants who, in the judgment of the Investigator, were noncompliant with trial procedures or with study treatment administration during the double-blind study (BUOY-1 Study).
- Female participants with a positive urine pregnancy test result. Female participants may be enrolled without a negative urine test if they are surgically sterile or at least 2 years post-menopause.
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 |
Primary outcome
Safety and tolerability assessments based on Treatment-emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs) and validated clinical scales and procedures
Time frame: Up to Day 49
Adverse events (AEs) are monitored from Day 1 to 49. A TEAE is as any AE with an onset after first dose of study treatment up to Day 49. Clinically significant abnormalities in clinical laboratory evaluations, ECGs, vital signs, physical examinations and Columbia Suicide Severity Rating Scale (C-SSRS) will be reported as TEAEs.
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
42 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 42 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 3 inclusion and 3 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: enrolling by invitation, 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 42 sites in United States, Poland, Czechia, Germany, Bulgaria 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. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety and tolerability assessments based on Treatment-emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs) and validated clinical scales and procedures (time frame: Up to Day 49). 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.