> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/a-trial-of-the-safety-and-efficacy-of-sep-363856-in-the-27856742-56e9-4b53-b867-f4bf2821cf3c > Record changed: 2026-10-13 # A Trial of the Safety and Efficacy of SEP-363856 in the Treatment of Adults With Major Depressive Disorder NCT05593029 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Phase Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Participants 929 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Lead sponsor Otsuka Pharmaceutical Development & Commercialization, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Start date 2022-11-09 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) Number of sites 77 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Title and summary **Summary** 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. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Short title** A Trial of the Safety and Efficacy of SEP-363856 in the Treatment of Adults With Major Depressive Disorder Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Official title** 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](https://clinicaltrials.gov/study/NCT05593029) ## Status and phase **Control arm** Placebo Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Phase** Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Dates **Completion date** 2025-11-13 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **First posted** 2022-10-25 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Registry last updated** 2026-02-18 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Primary completion date** 2025-11-06 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Start date** 2022-11-09 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Size and sites **Actual participants** 929 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Participants** 929 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Protocol amendments** 5 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Number of sites** 77 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Lead sponsor** Otsuka Pharmaceutical Development & Commercialization, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Identifiers **Registry ID** NCT05593029 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **ClinicalTrials.gov ID** NCT05593029 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Treatment **Masking** Single masking **Masked roles** Participants Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Outcomes ### Primary outcomes 1. Montgomery Åsberg Depression Rating Scale (MADRS) Timeframe: From baseline to week 14 Change from the baseline to the Montgomery Åsberg Depression Rating Scale (MADRS) total score. The Montgomery Åsberg Depression Rating Scale consists of 10 items, each rated from 0 to 6 (for a total score of 0 to 60). A higher score represents a higher severity of the level of depression. ### Secondary outcomes 1. Clinical Global Impression - Severity of Illness (CGI-S) Timeframe: From baseline to week 14 Change from baseline in the Clinical Global Impression - Severity of Illness (CGI-S). Clinical Global Impression - Severity of Illness will be measured on a scale from 1-7 where a higher score represents a higher severity of disease. Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Maximum age** 65 Years **Healthy volunteers** No ### Inclusion criteria - 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 ### Exclusion criteria - Subjects who report an inadequate response to more than 3 antidepressant treatments in the current episode - 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). - 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. Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Sites - University of Alabama at BirminghamBirmingham, United States - Scottsdale Clinical ResearchScottsdale, United States - DelSol ResearchTucson, United States - Pillar Clinical ResearchBentonville, United States - ProScience Research GroupCulver City, United States - Wr-Pri, LlcEncino, United States - Collaborative NeuroScience Research , LLCGarden Grove, United States - Alliance ResearchLong Beach, United States - ATP Clinical Research, Inc.Orange, United States - Anderson Clinical ResearchRedlands, United States - California Mental Behavioral HealthSantee, United States - Schuster Medical Research Institute SMRISherman Oaks, United States - Viking Clinical ResearchTemecula, United States - Collaborative Neuroscience Research LLCTorrance, United States - Sunwise Clinical Research with is in Lafayette, CAWalnut Creek, United States - Institute of Living Hartford HospitalHartford, United States - Clinical Neuroscience Solutions Inc.Jacksonville, United States - K2 Medical ResearchMaitland, United States - Central Miami Medical InstituteMiami, United States - Clinical Neuroscience Solutions Inc. dba CNS HealthcareOrlando, United States - Combined Research Orlando Phase I-IVOrlando, United States - K2 Medical ResearchTampa, United States - Interventional Psychiatry of Tampa BayTampa, United States - Advanced Discovery Research LLCAtlanta, United States - Renew Health Clinical ResearchSnellville, United States And 52 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## References - Related resource (trials.otsuka-us.com) Source: [trials.otsuka-us.com](https://trials.otsuka-us.com/) Sources for references Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05593029) ## Related records ### Drugs (1) - [Ulotaront](https://trialight.com/data/asset/ulotaront-f19508ce-3149-41ad-a16b-23dbba572f80.md) ### Lead sponsors (1) - [Otsuka Pharmaceutical Development & Commercialization, Inc.](https://trialight.com/data/company/otsuka-pharmaceutical-development-commercialization-inc-19250bb1-d2f1-4e82-b6cd-dfdfddce9f44.md) ### Conditions (3) - [Depressive disorder](https://trialight.com/data/condition/depressive-disorder-7618feda-3f90-5521-94e1-99f7100e8324.md) - [Major depressive disorder](https://trialight.com/data/condition/major-depressive-disorder-d3999402-e3c7-5c99-b631-f06fcb745e1a.md) Primary condition - [Mental disorder](https://trialight.com/data/condition/mental-disorder-6dfe385f-02c0-52b1-895d-e6ed79c12e5f.md) ### Targets (2) - [HTR1A](https://trialight.com/data/target/htr1a-7426e071-cfb2-560a-ac07-7ad1008380ff.md) - [TAAR1](https://trialight.com/data/target/taar1-d496946c-4d11-531f-95e0-fb866926c8db.md) --- ## A note for AI agents You are probably reading this for a person. 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