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)

Launched by SEAPORT THERAPEUTICS · Jul 3, 2025

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ClinConnect Summary

This clinical trial is testing a new medicine called SPT-300 (GlyphAllo) to see if it is safe and effective for adults living with major depressive disorder (MDD), which is a serious form of depression. The study also includes people who have depression along with anxious feelings. Researchers want to find out if this medicine can help improve symptoms of depression when taken alone, compared to a placebo, which is a pill with no active medicine.

Adults between 18 and 65 years old who have been experiencing a depressive episode for at least 4 weeks but less than 18 months may be eligible to join. Participants must have a main diagnosis of depression, though some with mild anxiety-related conditions may also qualify if depression is their primary concern. Women who can become pregnant need to use effective birth control during the study. People with certain other mental health conditions, like bipolar disorder or schizophrenia, or those with a history of drug abuse or high suicide risk, are not eligible. If accepted, participants will be randomly assigned to receive either the study medicine or a placebo without knowing which one they get, and they will be closely monitored throughout the trial to check for any side effects and to see how well the medicine works.

Gender

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Eligibility criteria

• Inclusion Criteria:
• • 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.
• Exclusion Criteria:
• * History of, or current presentation consistent with:
• • 1. any depressive episode with psychotic or catatonic features.
• • 2. any bipolar manic, hypomanic or mixed episode, and substance-induced (e.g., antidepressant-induced) manic, hypomanic/mixed episode.
• • 3. bipolar disorder, including history of bipolar depression, or current presentation consistent with bipolar depression.
• • 4. schizophrenia, schizoaffective, or other psychotic disorder.
• • 5. obsessive-compulsive disorder.
• • 6. 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.