NCT05593029CompletedPhase 2
A Trial of the Safety and Efficacy of SEP-363856 in the Treatment of Adults With Major Depressive Disorder
A Phase 2/3, Multicenter, Randomized, Double-blind, Placebo-controlled Trial of the Safety and Efficacy of Flexible Doses of SEP-363856 as Adjunctive Therapy in the Treatment of Adults With Major Depressive Disorder
Source: ClinicalTrials.gov · Last updated 18 Feb 2026
Brief summary (registry, in English)
Demonstrate ability of SEP-363856 to be superior to placebo as an adjunctive therapy to ADT in change from baseline in depressive symptoms (MADRS \& CGI-S) in MDD patients who had an inadequate response to prior ADT therapy.
- Status (registry)
- Completed
- Phase (registry)
- Phase 2
- Study type
- Interventional
- Enrollment
- 929 (actual)
- First submitted
- 10 Oct 2022
- Start date
- 9 Nov 2022
- Primary completion date
- 6 Nov 2025
- Lead sponsor
- Otsuka Pharmaceutical Development & Commercialization, Inc.
- Diseases
- Depression
- NCT number
- NCT05593029
What you commit to
- Study type: Interventional · Phase 2
- Participants enrolled: 929
- From 9 Nov 2022 to the primary completion date, 6 Nov 2025
- 77 sites in 7 countries
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Sexually active subjects, who could become pregnant, not agreeing to practice 2 sponsor approved methods of birth control or remain abstinent during the trial and for 30 days (females) or 90 days (males) after last dose of study drug.
Other illness
- Subjects with a lifetime history of schizophrenia spectrum or other psychotic disorder, bipolar or related disorder, major or mild neurocognitive disorder, neurodevelopmental disorder of greater than mild severity or of a severity that impacts the participant's ability to consent/ follow study directions/ or otherwise safely participate in the study, borderline or antisocial personality disorder.
- Subjects with a current diagnosis of post-traumatic stress disorder, obsessive compulsive disorder, panic disorder, or eating disorder (including anorexia nervosa or bulimia).
Other
- Subjects who report an inadequate response to more than 3 antidepressant treatments in the current episode
Who the study is looking for
- Male and Female subjects between 18-65 years of age, with a primary diagnosis of major depressive disorder and in a current major depressive episode
- Current major depressive episode must be at least 8 weeks and no longer than 2 years in duration
- History of an inadequate response to at least 1 and no more than 3 antidepressant treatments in the current major depressive episode
Age in the registry: 18 years to 65 years · Sex: All · Does not accept healthy volunteers
Sites (77)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Diagnostic Consultive Center Higya AD Coordinator of this site? Confirm its status | Pazardzhik | Bulgaria | Unknown status |
| Ambulatory for Group Practice for Specialized Psychiatrics Help PHILIPOPOLIS OOD Coordinator of this site? Confirm its status | Plovdiv | Bulgaria | Unknown status |
| Medical Center Sveti Naum Coordinator of this site? Confirm its status | Sofia | Bulgaria | Unknown status |
| DCC-Mladost M OOD Coordinator of this site? Confirm its status | Varna | Bulgaria | Unknown status |
| Mental Health Center Vratsa Coordinator of this site? Confirm its status | Vratsa | Bulgaria | Unknown status |
| Chatham-Kent Clinical Trials Research Centre Coordinator of this site? Confirm its status | Chatham | Canada | Unknown status |
| Institute of Mental Health Research IMHR Coordinator of this site? Confirm its status | Ottawa | Canada | Unknown status |
| Centre for Addiction and Mental Health (CAMH & University of Toronto) Coordinator of this site? Confirm its status | Toronto | Canada | Unknown status |
| Brain-Soultherapy s.r.o. Coordinator of this site? Confirm its status | Kladno | Czechia | Unknown status |
| National Institute of Mental Health Coordinator of this site? Confirm its status | Klecany | Czechia | Unknown status |
| Clintrial S.R.O. Coordinator of this site? Confirm its status | Prague | Czechia | Unknown status |
| A-Shine s.r.o. Coordinator of this site? Confirm its status | Ptzen | Czechia | Unknown status |
| Pharmakologisches Studienzentrum Chemnitz GmbH Coordinator of this site? Confirm its status | Chemnitz | Germany | Unknown status |
| Somni Bene Institut for Medical Research Coordinator of this site? Confirm its status | Schwerin | Germany | Unknown status |
| Private Practice Kusserow Coordinator of this site? Confirm its status | Stralsund | Germany | Unknown status |
| Arztepartnerschaft Dr. med. J. Springhub/ W. Schwarz-Studienzentrum Nord-West Coordinator of this site? Confirm its status | Westerstede | Germany | Unknown status |
| Velocity Clinical Research Wiesbaden Coordinator of this site? Confirm its status | Wiesbaden | Germany | Unknown status |
| Clinexpert Kft. Coordinator of this site? Confirm its status | Budapest | Hungary | Unknown status |
| Semmelweis University Coordinator of this site? Confirm its status | Budapest | Hungary | Unknown status |
| MlynowaMed - Bialystok Coordinator of this site? Confirm its status | Bialystok | Poland | Unknown status |
| Osrodek Badan Klinicznych CLINSANTE Coordinator of this site? Confirm its status | Bydgoszcz | Poland | Unknown status |
| Centrum Medyczne Luxmed Sp.z. o.o. Coordinator of this site? Confirm its status | Lublin | Poland | Unknown status |
| Praktyka Lekarska Malgorzata Wojtanowska-Bogacka Coordinator of this site? Confirm its status | Poznan | Poland | Unknown status |
| Indywidualna SpecjalistycznaPraktyka Lekarska AgnieszkaRemlinger-Molenda Coordinator of this site? Confirm its status | Szkolkarska 32 | Poland | Unknown status |
| Advanced Discovery Research, Llc Coordinator of this site? Confirm its status | Atlanta | United States | Unknown status |
| Donald J Garcia Jr, MD, PA Coordinator of this site? Confirm its status | Austin | United States | Unknown status |
| Community Clinical Research, Inc. Coordinator of this site? Confirm its status | Austin | United States | Unknown status |
| Pillar Clinical Research Coordinator of this site? Confirm its status | Bentonville | United States | Unknown status |
| University of Alabama at Birmingham Coordinator of this site? Confirm its status | Birmingham | United States | Unknown status |
| NeuroBehavioral Medicine Group Coordinator of this site? Confirm its status | Bloomfield Hills | United States | Unknown status |
| Copley Clinical Coordinator of this site? Confirm its status | Boston | United States | Unknown status |
| Integrative Clinical Trials Coordinator of this site? Confirm its status | Brooklyn | United States | Unknown status |
| Center For Emotional Fitness Coordinator of this site? Confirm its status | Cherry Hill | United States | Unknown status |
| MetroMed Clinical Trials Coordinator of this site? Confirm its status | Chicago | United States | Unknown status |
| Patient Priority Clinical Studies LLC Coordinator of this site? Confirm its status | Cincinnati | United States | Unknown status |
| The Ohio State University Coordinator of this site? Confirm its status | Columbus | United States | Unknown status |
| ProScience Research Group Coordinator of this site? Confirm its status | Culver City | United States | Unknown status |
| FutureSearch Trials of Dallas Coordinator of this site? Confirm its status | Dallas | United States | Unknown status |
| Wr- Pri, Llc Coordinator of this site? Confirm its status | Encino | United States | Unknown status |
| Core Clinical Research Coordinator of this site? Confirm its status | Everett | United States | Unknown status |
| Precise Research Centers Coordinator of this site? Confirm its status | Flowood | United States | Unknown status |
| North Texas Clinical Trials Coordinator of this site? Confirm its status | Fort Worth | United States | Unknown status |
| Cenexel CBH (CBH Health) Coordinator of this site? Confirm its status | Gaithersburg | United States | Unknown status |
| Collaborative NeuroScience Research , LLC Coordinator of this site? Confirm its status | Garden Grove | United States | Unknown status |
| Institute of Living Hartford Hospital Coordinator of this site? Confirm its status | Hartford | United States | Unknown status |
| DM Clinical Research - Belliare Coordinator of this site? Confirm its status | Houston | United States | Unknown status |
| Basil Clinical Coordinator of this site? Confirm its status | Inwood | United States | Unknown status |
| Clinical NeuroScience Solutions Inc Coordinator of this site? Confirm its status | Jacksonville | United States | Unknown status |
| Alliance Research Coordinator of this site? Confirm its status | Long Beach | United States | Unknown status |
| K2 Medical Research Coordinator of this site? Confirm its status | Maitland | United States | Unknown status |
| Clinical Neuroscience Solutions, Inc. Coordinator of this site? Confirm its status | Memphis | United States | Unknown status |
| Central Miami Medical Institute Coordinator of this site? Confirm its status | Miami | United States | Unknown status |
| Psychiatric And Behavioral Solutions, LLC Coordinator of this site? Confirm its status | Millcreek | United States | Unknown status |
| Manhattan Behavioral Medicine PLLC Coordinator of this site? Confirm its status | New York | United States | Unknown status |
| The Medical Research Network, LLC Coordinator of this site? Confirm its status | New York | United States | Unknown status |
| Berman Clinical Coordinator of this site? Confirm its status | New York | United States | Unknown status |
| Sooner Clinical Research Coordinator of this site? Confirm its status | Oklahoma City | United States | Unknown status |
| ATP Clinical Research, Inc. Coordinator of this site? Confirm its status | Orange | United States | Unknown status |
| Clinical Neuroscience Solutions Inc. dba CNS Healthcare Coordinator of this site? Confirm its status | Orlando | United States | Unknown status |
| Combined Research Orlando Phase I-IV Coordinator of this site? Confirm its status | Orlando | United States | Unknown status |
| Anderson Clinical Research Coordinator of this site? Confirm its status | Redlands | United States | Unknown status |
| Boston Clinical Trials Coordinator of this site? Confirm its status | Roslindale | United States | Unknown status |
| California Mental Behavioral Health Coordinator of this site? Confirm its status | Santee | United States | Unknown status |
| Scottsdale Clinical Research Coordinator of this site? Confirm its status | Scottsdale | United States | Unknown status |
| Schuster Medical Research Institute SMRI Coordinator of this site? Confirm its status | Sherman Oaks | United States | Unknown status |
| Benchmark Research Coordinator of this site? Confirm its status | Shreveport | United States | Unknown status |
| Renew Health Clinical Research Coordinator of this site? Confirm its status | Snellville | United States | Unknown status |
| Interventional Psychiatry of Tampa Bay Coordinator of this site? Confirm its status | Tampa | United States | Unknown status |
| K2 Medical Research Coordinator of this site? Confirm its status | Tampa | United States | Unknown status |
| Viking Clinical Research Coordinator of this site? Confirm its status | Temecula | United States | Unknown status |
| Collaborative Neuroscience Research LLC Coordinator of this site? Confirm its status | Torrance | United States | Unknown status |
| DelSol Research Coordinator of this site? Confirm its status | Tucson | United States | Unknown status |
| Sunwise Clinical Research with is in Lafayette, CA Coordinator of this site? Confirm its status | Walnut Creek | United States | Unknown status |
| AMR Convention Research Coordinator of this site? Confirm its status | Warrenville | United States | Unknown status |
| Adams Clinical Coordinator of this site? Confirm its status | Watertown | United States | Unknown status |
| Suburban Research Associates Coordinator of this site? Confirm its status | West Chester | United States | Unknown status |
| Vitalix Clinical Coordinator of this site? Confirm its status | Worcester | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.