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Evaluating SP-624 for treating major depressive disorder in adults

A Multi-center, Double-Blind, Randomized, Placebo-Controlled Study of the Efficacy and Safety of SP-624 in the Treatment of Adults With Major Depressive Disorder

PHASE2 · Sirtsei Pharmaceuticals, Inc. · NCT06254612

This study is testing a new treatment called SP-624 to see if it can help adults with major depressive disorder feel better compared to a placebo.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment456 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorSirtsei Pharmaceuticals, Inc. (industry)
Locations50 sites (Phoenix, Arizona and 49 other locations)
Trial IDNCT06254612 on ClinicalTrials.gov

What this trial studies

This Phase 2B clinical study assesses the efficacy and safety of SP-624 compared to a placebo in adults diagnosed with Major Depressive Disorder (MDD). Participants aged 18 to 65 who meet the DSM-5 criteria for moderate to severe MDD will be enrolled. The study aims to determine whether SP-624 can provide a significant improvement in depressive symptoms. The trial will monitor participants for safety and effectiveness over the course of the study.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 to 65 with moderate to severe major depressive disorder.

Not a fit: Patients with a history of psychotic disorders, bipolar disorder, or significant cardiovascular issues may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could offer a new therapeutic option for adults suffering from major depressive disorder.

How similar studies have performed: Other studies have shown promise in treating major depressive disorder with novel pharmacological approaches, suggesting potential for success with SP-624.

Eligibility criteria

Show full inclusion / exclusion criteria 
Key Inclusion Criteria:

* Males and females, aged 18 to 65 years, inclusive.
* Meet DSM-5 criteria for moderate to severe MDD, as confirmed by the Mini International Neuropsychiatric Interview (MINI).
* In generally good physical health, in the opinion of the Investigator.
* Body mass index (BMI) must be ≥ 18 and ≤ 45 kg/m2.

Key Exclusion Criteria:

* Female who is pregnant, breastfeeding, or less than 6 months postpartum at screen.
* A history of or current DSM-5 diagnosis of MDD with psychotic features, any schizophrenia spectrum and other psychotic disorders, bipolar disorder, or personality disorder.
* Presence or history of any known clinically significant cardiovascular disorders including, but not limited to: coronary artery disease, heart failure, valvular heart disease, cardiomyopathies, myocardial infarction, chamber enlargement or hypertrophy, or orthostatic hypotension.
* Presence of uncontrolled hypertension, defined as consistent sitting systolic blood pressure (SBP) \>160 mmHg or consistent sitting diastolic blood pressure (DBP) \>95 mmHg despite present therapy.
* Screening laboratory value(s) outside the laboratory reference range that are considered to be clinically significant by the Investigator (clinical chemistry, hematology, thyroid function, and urinalysis).

Where this trial is running

Phoenix, Arizona and 49 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Major Depressive Disorder

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.