A Clinical Trial That Will Study the Efficacy and Safety of an Investigational Drug in Acutely Psychotic People With Schizophrenia

A Randomized, Double-blind, Parallel-group, Placebo-controlled, Fixed-dose, Multicenter Study to Evaluate the Efficacy and Safety of SEP-363856 in Acutely Psychotic Subjects With Schizophrenia

A clinical trial to study the efficacy and safety of an investigational drug in acutely psychotic people with schizophrenia. Participants in the study will either receive the drug being studied or a placebo. This study is accepting male and female participants between 18 -65 years old who have been diagnosed with schizophrenia. This study will be conducted in 60 locations world wide. The study will last up to nine (9) weeks.

Study Overview

• Status: Completed
• Conditions: Schizophrenia
• Intervention / Treatment: Drug: SEP-363856 75mg; Drug: Placebo; Drug: SEP-363856 100mg

Detailed Description

This is a multicenter, randomized, double-blind, parallel-group, fixed-dosed study evaluating the efficacy and safety of two doses of SEP-363856 (75 and 100 mg/day) versus placebo over a 6-week Treatment Period in acutely psychotic participants with schizophrenia. This study is projected to randomize approximately 462 participants to 3 treatment groups (SEP-363856 75 mg/day, SEP-363856 100 mg/day, or placebo) in a 1:1:1 ratio. Treatment assignment will be stratified by country. Study drug will be taken once a day and may be taken with or without food.

This study is designed to test the hypotheses that treatment with SEP-363856 in adult participants with schizophrenia will result in significantly greater reduction (i.e. improvement) in PANSS total score and CGI-S score at Week 6 from Baseline when compared to placebo. The overall Type I error is controlled for two hierarchical families of hypotheses. The first family includes hypotheses about the testing of change from Baseline in PANSS total score at Week 6 between each of the SEP-363856 dose levels vs. placebo. The second family of hypotheses are about the testing of change from Baseline in CGI-S score at Week 6 between each of the SEP-363856 dose levels vs. placebo.

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.

• Study Type: Interventional
• Enrollment (Actual): 464
• Phase: Phase 3

Contacts and Locations

Study Locations

• Bulgaria
  • Burgas, Bulgaria, 8000
    • Research Site
  • Kardzhali, Bulgaria, 6600
    • Research Site
  • Novi Iskar, Bulgaria, 1282
    • Research Site
  • Plovdiv, Bulgaria, 4000
    • Research Site
  • Sofia, Bulgaria, 1431
    • Research Site
  • Sofia, Bulgaria, 1202
    • Research Site
• Croatia
  • Zagreb, Croatia, 10090
    • Research Site
• Latvia
  • Daugavpils, Latvia, LV-5417
    • Research Site
  • Riga, Latvia, LV-1005
    • Research Site
  • Strenči, Latvia, LV-4730
    • Research Site
• Russia
  • Arkhangelsk, Russia, 163530
    • Research Site
  • Engel's, Russia, 413124
    • Research Site
  • Moscow, Russia, 117152
    • Research Site
  • Moscow, Russia, 141371
    • Research Site
  • Saint Petersburg, Russia, 197341
    • Research Site
  • Saint Petersburg, Russia, 192019
    • Research Site
  • Saint Petersburg, Russia, 188820
    • Research Site
  • Saint Petersburg, Russia, 190005
    • Research Site
  • Saratov, Russia, 410028
    • Research Site
  • Saratov, Russia, 410060
    • Research Site
  • Stavropol, Russia, 357034
    • Research Site
  • Tomsk, Russia, 634014
    • Research Site
• Serbia
  • Belgrade, Serbia, 11000
    • Research Site
  • Kovin, Serbia, 26220
    • Research Site
  • Kragujevac, Serbia, 34000
    • Research Site
  • Niš, Serbia, 18000
    • Research Site
  • Novi Kneževac, Serbia, 23330
    • Research Site
  • Vršac, Serbia, 26300
    • Research Site
• Ukraine
  • Kharkiv, Ukraine, 61068
    • Research Site
  • Kherson, Ukraine, 73488
    • Research Site
  • Kyiv, Ukraine, 01030
    • Research Site
  • Kyiv, Ukraine, 01133
    • Research Site
  • Kyiv, Ukraine, 08631
    • Research Site
  • Lviv, Ukraine, 79021
    • Research Site
  • Vinnytsia, Ukraine, 21005
    • Research Site
• United States
  • Arkansas
    • Rogers, Arkansas, United States, 72758
      • Research Site
  • California
    • Anaheim, California, United States, 92805
      • Research Site
    • Bellflower, California, United States, 90706
      • Research Site
    • Culver City, California, United States, 90230
      • Research Site
    • Long Beach, California, United States, 90806
      • Research Site
    • San Diego, California, United States, 92102
      • Research Site
    • Sherman Oaks, California, United States, 91403
      • Research Site
  • Florida
    • Hollywood, Florida, United States, 33021
      • Research Site
    • Miami Springs, Florida, United States, 33166
      • Research Site
  • Georgia
    • Atlanta, Georgia, United States, 30331
      • Research Site
    • Decatur, Georgia, United States, 30030
      • Research Site
  • Illinois
    • Chicago, Illinois, United States, 60641
      • Research Site
  • Louisiana
    • Lake Charles, Louisiana, United States, 70629
      • Research Site
  • Maryland
    • Gaithersburg, Maryland, United States, 20877
      • Research Site
  • Missouri
    • St Louis, Missouri, United States, 63125
      • Research Site
  • New Jersey
    • Marlton, New Jersey, United States, 08053
      • Research Site
  • New York
    • New York, New York, United States, 10032
      • Research Site
  • Texas
    • Richardson, Texas, United States, 75080
      • Research Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male or female participant between 18 to 65 years of age (inclusive) at the time of consent.
2. Participant must give written informed consent and privacy authorization prior to participation in the study.
3. Participant meets the Diagnostic and Statistical Manual of Mental Illnesses (DSM-5 )criteria for schizophrenia as established by clinical interview at screeing.
4. Participant must have a Clinical Global Impression - Severity (CGI-S) score ≥ 4.
5. Participant must have a Positive and Negative Syndrome Scale (PANSS) total score ≥ 80 and a PANSS item score ≥ 4 on 2 or more of the following PANSS items: delusions, conceptual disorganization, hallucinations, and unusual thought content.
6. Participant has an acute exacerbation of psychotic symptoms (persisting no longer than 2 months prior to providing informed consent).
7. Participant has marked deterioration of functioning in one or more areas.
8. Participant is, in the opinion of the Investigator, generally healthy based on screening medical history, physical examination (PE), neurological examination, vital signs, electrocardiogram (ECG) and clinical laboratory values.

Exclusion Criteria:

1. Participant has a 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, bipolar I or II disorder, schizoaffective disorder, obsessive compulsive disorder, and posttraumatic stress disorder. Symptoms of mild to moderate mood dysphoria or anxiety are allowed so long as these symptoms are not the primary focus of treatment.
2. Participant is at significant risk of harming self, others, or objects based on Investigator's judgment.
3. 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
4. Female participant who is pregnant or lactating
5. Participant has any clinically significant abnormal laboratory value(s) at Screening as determined by investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SEP-363856 75mg; SEP-363856 75mg dosed once daily	Drug: SEP-363856 75mg; SEP-363856 75mg tablet dosed once daily
Placebo Comparator: Placebo; Placebo dosed once daily	Drug: Placebo; Placebo tablet dosed once daily
Experimental: SEP-363856 100mg; SEP-363856 100mg dosed once daily	Drug: SEP-363856 100mg; SEP-363856 100mg tablet dosed once daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in PANSS Total Score at Week 6	PANSS was an interview-based assessment comprised of 30 items and 3 subscales (Positive, Negative, General Psychopathology). The Positive subscale assessed hallucinations, delusions, and related symptoms; the Negative subscale assessed emotional withdrawal, lack of motivation, and similar symptoms; and the General Psychopathology subscale addressed other symptoms such as anxiety, somatic concern, and disorientation. An anchored Likert scale from 1 - 7, where values of 2 and above indicated the presence of progressively more severe symptoms, was used to score each item. Individual items were then summed to determine scores for the 3 subscales, as well as a total score. PANSS total score ranges from: 30-210, where a higher score indicates greater severity. A negative change from baseline indicates improvement.	Baseline, Week 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in CGI-S Score at Week 6	The CGI-S is a single-item clinician-rated assessment of the participant's current illness state on a 7-point scale (score range: 1-7), where a higher score is associated with greater illness severity. A negative change from baseline indicates improvement.	Baseline, Week 6

Collaborators and Investigators

• Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc.
• Investigators: Study Chair: CNS Medical Director, Sumitomo Pharma America, Inc.

Publications and helpful links

Helpful Links

• Otsuka Clinical Trial Website
• Otsuka Clinical Trial Transparency

Study record dates

Study Major Dates

• Study Start (Actual): October 14, 2019
• Primary Completion (Actual): June 14, 2023
• Study Completion (Actual): June 14, 2023

Study Registration Dates

• First Submitted: September 13, 2019
• First Submitted That Met QC Criteria: September 13, 2019
• First Posted (Actual): September 17, 2019

Study Record Updates

• Last Update Posted (Actual): June 18, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Schizophrenia; acute psychosis
• Additional Relevant MeSH Terms: Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Schizophrenia; SEP-363856
• Other Study ID Numbers: SEP361-302; 2019-000697-37 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymized Individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.
• IPD Sharing Time Frame: Data will be available after marketing approval in global markets, or beginning 1-3 years following article publication. There is no end date to the availability of the data.
• IPD Sharing Access Criteria: Otsuka will share data on the Vivli data sharing platform which can be found here: https://vivli.org/ourmember/Otsuka/
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No