A Study of the Long-term Safety and Tolerability of an Investigational Drug in People With Schizophrenia.

Recruitment Status
COMPLETED - HAS RESULTS
(See Contacts and Locations)Verified August 2024 by Otsuka Pharmaceutical Development & Commercialization, Inc.
Sponsor
Otsuka Pharmaceutical Development & Commercialization, Inc.
Information Provided by (Responsible Party)
Otsuka Pharmaceutical Development & Commercialization, Inc.
Clinicaltrials.gov Identifier
NCT04115319
Other Study ID Numbers:
SEP361-304
First Submitted
October 1, 2019
First Posted
October 3, 2019
Results First Posted
December 9, 2025
Last Update Posted
December 30, 2025
Last Verified
August 2024

ClinicalTrials.gov processed this data on December 2025. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

This is a 52-week, multicenter, randomized, double-blind, parallel-group, flexible-dose study designed to evaluate the long-term safety and tolerability of SEP-363856 (50 to 100 mg/day) compared with quetiapine XR (400 to 800 mg/day) in clinically stable adult participants with schizophrenia. This study is projected to randomize a least 300 participants to two treatment groups (SEP-363856 50 to 100 mg/day or quetiapine XR 400 to 800 mg/day) in a 2:1 ratio. Study drug will be taken once a day and may be taken without food or with a light meal.

Sumitomo Pharma America Inc. was the former Sponsor and conducted this study. Sumitomo was responsible for analysis and clinical study report (CSR) completion. Otsuka took over study after IND was transferred and is concluding activities with registry postings.

Condition or DiseaseIntervention/Treatment
Schizophrenia
Drug: SEP363856Drug: quetiapine XR

Study Design

Study TypeInterventional
Actual Enrollment305 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingQuadruple
Primary PurposeTreatment
Official TitleA Randomized, Double-blind, Active Comparator-Controlled Study to Evaluate the Long-term Safety and Tolerability of SEP-363856 in Subjects With Schizophrenia
Study Start DateNovember 20, 2019
Actual Primary Completion DateDecember 29, 2022
Actual Study Completion DateDecember 29, 2022

Groups and Cohorts

Group/CohortIntervention/Treatment
SEP363856
SEP363856 50mg, 75mg, 100mg, flexibly dosed once daily capsule
Drug: SEP363856
SEP-363856, 50mg, 75mg, 100mg, flexibly dosed once daily capsule
quetiapine XR
quetiapine XR, 400, 600, 800 mg, flexibly dosed once daily capsule
Drug: quetiapine XR
quetiapine XR, 400, 600, 800 mg, flexibly dosed once daily capsule

Outcome Measures

Primary Outcome Measures
  1. Number of Participants With Adverse Events (AEs), Serious Adverse Events (SAEs), and Adverse Events (AEs) Leading to Study Discontinuation
    An AE was any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Untoward medical occurrences that occured after first administration of study drug were considered AEs. A SAE is an AE that meets one or more criteria: results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity, or is a congenital anomaly or birth defect.

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
Inclusion criteria: The main inclusion criteria include, but are not limited to the following:
Male or female participant between 18 to 65 years of age (inclusive) at the time of consent.
Participant meets DSM-5 criteria for a diagnosis of schizophrenia as established by clinical interview at screening (using the DSM-5 as a reference and confirmed using the SCID-CT). The time since the participant's diagnosis must be ≥ 1 year prior to Screening.
Participant must have a CGI-S score ≤ 4 at Screening and Baseline.
Participant must have a PANSS total score ≤ 80 at Screening and Baseline.
Participant is judged to be clinically stable (i.e., no evidence of an acute exacerbation) by the Investigator for at least 8 weeks prior to Screening.
Participant has had no change in antipsychotic medication(s) (minor dose adjustments for tolerability purposes are permitted) for at least 6 weeks prior to Screening.
Participants taking an antipsychotic agent at Screening may participate in this study only if there are signs of intolerability or lack of efficacy of the current antipsychotic (as determined by the Investigator).
Participant is, in the opinion of the Investigator, generally healthy based on Screening medical history, PE, neurological examination, vital signs, electrocardiogram (ECG) and clinical laboratory values (hematology, chemistry and urinalysis).
Exclusion Criteria
Inclusion criteria: The main inclusion criteria include, but are not limited to the following:
Male or female participant between 18 to 65 years of age (inclusive) at the time of consent.
Participant meets DSM-5 criteria for a diagnosis of schizophrenia as established by clinical interview at screening (using the DSM-5 as a reference and confirmed using the SCID-CT). The time since the participant's diagnosis must be ≥ 1 year prior to Screening.
Participant must have a CGI-S score ≤ 4 at Screening and Baseline.
Participant must have a PANSS total score ≤ 80 at Screening and Baseline.
Participant is judged to be clinically stable (i.e., no evidence of an acute exacerbation) by the Investigator for at least 8 weeks prior to Screening.
Participant has had no change in antipsychotic medication(s) (minor dose adjustments for tolerability purposes are permitted) for at least 6 weeks prior to Screening.
Participants taking an antipsychotic agent at Screening may participate in this study only if there are signs of intolerability or lack of efficacy of the current antipsychotic (as determined by the Investigator).
Participant is, in the opinion of the Investigator, generally healthy based on Screening medical history, PE, neurological examination, vital signs, electrocardiogram (ECG) and clinical laboratory values (hematology, chemistry and urinalysis). Exclusion criteria: Main exclusion criteria include, but are not limited to:
Participant was hospitalized for a psychiatric illness within the 8 weeks prior to Screening.
Participant has a current DSM-5 diagnosis or presence of symptoms consistent with a DSM-5 diagnosis other than schizophrenia. Exclusionary disorders include but are not limited to alcohol use disorder (within past 12 months), substance (other than nicotine or caffeine) use disorder within past 12 months, or lifetime history of significant substance abuse that, in the opinion of the Investigator or Sponsor, may have had a significant and potentially permanent impact on the brain or other body systems, major depressive disorder, schizoaffective disorder, ,bipolar I or II disorder, obsessive compulsive disorder, and posttraumatic stress disorder, symptoms of mild to moderate mood dysphoria or anxiety are allowed so long as theses symptoms are not the primary focus of treatment.
Participant is judged to be resistant to antipsychotic treatment by the Investigator, based on failure to respond to 2 or more marketed antipsychotic agents within a 1-year period prior to Screening, given at adequate dose as per labeling, for at least 4 weeks.
Participant answers "yes" to "Suicidal Ideation" Item 4 (active suicidal ideation with some intent to act, without specific plan) or Item 5 (active suicidal ideation with specific plan and intent) on the C-SSRS assessment at Screening (i.e., in the past one month) or at Baseline (i.e., since last visit).
Participant is at significant risk of harming self or others based on Investigator's judgment.
Participant has attempted suicide within 6 months prior to Screening.
Participant has received treatment with a psychotropic medication or herbal supplement within 3 days or 5 half-lives (whichever is longer)
Participant has been treated with quetiapine or quetiapine XR within the 6 weeks prior to Screening or has a history of inadequate response or intolerability to quetiapine or quetiapine XR.
Participant has any clinically significant unstable medical condition or any clinically significant chronic disease that in the opinion of the Investigator, would limit the participant's ability to complete and/or participate in the study.
Participant has any clinically significant abnormal laboratory value(s) at Screening as determined by investigator.

Contacts and Locations

Sponsors and CollaboratorsOtsuka Pharmaceutical Development & Commercialization, Inc.
Locations
Research Site | Cerritos California, United States, 90703Research Site | Oakland California, United States, 94607Research Site | Oceanside California, United States, 92056Research Site | San Diego California, United States, 92103Research Site | Torrance California, United States, 90502Research Site | Miami Florida, United States, 33122Research Site | Miami Lakes Florida, United States, 33016Research Site | Atlanta Georgia, United States, 30328Research Site | Hoffman Estates Illinois, United States, 60169Research Site | Lincolnwood Illinois, United States, 60712Research Site | Shreveport Louisiana, United States, 71101Research Site | St Louis Missouri, United States, 63128Research Site | Las Vegas Nevada, United States, 89102Research Site | Cedarhurst New York, United States, 11516Research Site | Jamaica New York, United States, 11432Research Site | Rochester New York, United States, 14618Research Site | Charlotte North Carolina, United States, 28211Research Site | North Canton Ohio, United States, 44720Research Site | Brasov , Romania, 500079Research Site | Bucharest , Romania, 041914Research Site | Bucharest , Romania, 060222Research Site | Bucharest , Romania, 41914,Research Site | Iași , Romania, 700282Research Site | Arkhangelsk , Russia, 163530Research Site | Moscow , Russia, 127083Research Site | Omsk , Russia, 644070Research Site | Saint Petersburg , Russia, 188357Research Site | Saint Petersburg , Russia, 190121Research Site | Saint Petersburg , Russia, 192019Research Site | Saint Petersburg , Russia, 195176Research Site | Saint Petersburg , Russia, 199106Research Site | Smolensk , Russia, 214031Research Site | Stavropol , Russia, 357034Research Site | Tomsk , Russia, 634014Research Site | Yaroslavl , Russia, 150003Research Site | Yekaterinburg , Russia, 620030Research Site | Ivano-Frankivsk , Ukraine, 76011Research Site | Kharkiv , Ukraine, 61068Research Site | Kyiv , Ukraine, 03049Research Site | Smila , Ukraine, 20708Research Site | Ternopil , Ukraine, 46027Research Site | Uzhhorod , Ukraine, 88000
Study Documents (Full Text)
Documents provided by Otsuka Pharmaceutical Development & Commercialization, Inc.: Study Protocol  January 13, 2021Documents provided by Otsuka Pharmaceutical Development & Commercialization, Inc.: Statistical Analysis Plan  January 29, 2023