A Clinical Study That Will Evaluate How Well SEP-363856 Works and How Safe it is in People With Schizophrenia That Switch to SEP-363856 From Their Current Antipsychotic Medication

An 8-Week, Open-Label Study Evaluating the Effectiveness, Safety and Tolerability of SEP-363856 in Subjects With Schizophrenia Switched From Typical or Atypical Antipsychotic Agents

This study evaluated how well SEP-363856 works and how safe it is in people with schizophrenia that switch to SEP-363856 from their current antipsychotic medication.

Study Overview

• Status: Completed
• Conditions: Schizophrenia
• Intervention / Treatment: Drug: SEP-363856

Detailed Description

This was an 8-week, outpatient, multicenter, open-label, single-group, flexible-dose study.

Following a screening period of up to 21 days, eligible participants took part in the study. In the 8-week treatment period, participants were treated with SEP-363856 while continuing to take the full dose of their pre-switch antipsychotic. After the end of the treatment period, participants were required to complete the follow-up visit, 7 days after the last dose of SEP-363856.

• Study Type: Interventional
• Enrollment (Actual): 101
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • California
    • Anaheim, California, United States, 92805
      • Advanced Research Center, Inc.
    • Bellflower, California, United States, 90706
      • Clinical Innovations Inc.
    • Culver City, California, United States, 90230
      • Proscience Research Group
    • Garden Grove, California, United States, 92845
      • Collaborative Neuroscience Research, LLC
    • Lemon Grove, California, United States, 91945
      • Synergy San Diego
    • Riverside, California, United States, 92506
      • Clinical Innovations, Inc
    • San Diego, California, United States, 92102
      • California Neuropsychopharmacology Clinical Research Institute, LLC (CNRI-San Diego, LLC)
    • Santee, California, United States, 92071
      • CMB Clinical Trials
    • Torrance, California, United States, 90502
      • Cenexel CNS Research
  • Florida
    • Hollywood, Florida, United States, 33021
      • Larkin Behavioral Health Services
    • Miami, Florida, United States, 33122
      • Premier Clinical Research Institute, Inc.
    • Miami, Florida, United States, 33135
      • Wellness Research Center
    • Orlando, Florida, United States, 32803
      • Nova Psychiatry, Inc.
  • Georgia
    • Atlanta, Georgia, United States, 30331
      • Atlanta Center for Medical Research
    • Atlanta, Georgia, United States, 30318
      • Advanced Discovery Research LLC
    • Atlanta, Georgia, United States, 30358
      • Atlanta Behavioral Research
  • Illinois
    • Chicago, Illinois, United States, 60640
      • Uptown Research
  • Maryland
    • Gaithersburg, Maryland, United States, 20877
      • CBH Health
  • Missouri
    • St Louis, Missouri, United States, 63128
      • PsychCare Consultants Research
  • Nevada
    • Las Vegas, Nevada, United States, 89102
      • Ima Clinical Research
  • New Jersey
    • Berlin, New Jersey, United States, 08009
      • Hassman Research Institute
  • North Carolina
    • Charlotte, North Carolina, United States, 28211
      • New Hope Clinical Research
    • Hickory, North Carolina, United States, 28601
      • Clinical Trials of America, LLC
  • Ohio
    • Garfield Heights, Ohio, United States, 44125
      • Charak Clinical Research Center
  • Texas
    • Richardson, Texas, United States, 75080
      • Pillar Clinical Research, LLC

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria: This list is not all inclusive

• Participants meets Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for a diagnosis of schizophrenia.
• Participants are judged to be clinically stable (ie, no evidence of an acute exacerbation of schizophrenia) by the Investigator for at least 8 weeks prior to Baseline.
• Participants must be judged by the Investigator to be an appropriate candidate for switching current antipsychotic medication due to safety or tolerability concerns and/or insufficient efficacy.
• Participants are taking an oral antipsychotic and the antipsychotic regimen has been stable for at least 6 weeks prior to Screening.

Exclusion Criteria:This list is not all inclusive

• Participant has a current DSM-5 diagnosis or presence of symptoms consistent with a major psychiatric disorder, other than schizophrenia, that is the primary focus of treatment.
• Participants are at significant risk of harming self or others based on investigator's judgment.
• 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.
• Female participant who is pregnant or lactating.
• Participant tests positive for drugs of abuse at Screening.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SEP-363856; Participants received flexible doses of SEP-363856 50 to 100 milligrams per day (mg/day), orally, once daily (QD) up to Week 8. The dose was titrated up from 50 mg/day on Days 1 to 3, to 75 mg/day on Days 4 to 7. Beginning Day 8, the dose was adjusted within the range of 50 mg/day to 100 mg/day in 25 mg increments (i.e. 50, 75, or 100 mg/day) up to Week 8.	Drug: SEP-363856; SEP-363856 flexibly dosed for 8 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Who Discontinued From the Study Due to Clinical Reasons	Discontinuation for clinical reasons was defined as reasons due to adverse event (AE) or lack of efficacy. AEs are defined as untoward medical occurrences that started at the same time of or after the first dose of study drug. The percentage of participants who discontinued for clinical reasons was calculated by a proportion consisting of the number of participants who experience a discontinuation event due to clinical reasons as the numerator divided by the number of participants in the safety population as the denominator multiplied by 100 along with a corresponding 95% confidence interval (CI). 95% CI was calculated using the normal approximation method.	From the first dose of the study drug up to end of follow up (up to Week 9)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Who Discontinued From the Study Due to Any Reason	The percentage of participants who discontinued from the study due to any reason was calculated by a proportion consisting of the number of participants who experience a discontinuation event due to any reason as the numerator divided by the number of participants in the safety population as the denominator multiplied by 100 along with a corresponding 95% CI. 95% CI was calculated using the normal approximation method.	From first dose of the study drug up to end of follow-up period (up to Week 9)

Collaborators and Investigators

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

Study record dates

Study Major Dates

• Study Start (Actual): December 19, 2022
• Primary Completion (Actual): April 1, 2024
• Study Completion (Actual): April 1, 2024

Study Registration Dates

• First Submitted: November 16, 2022
• First Submitted That Met QC Criteria: November 16, 2022
• First Posted (Actual): November 28, 2022

Study Record Updates

• Last Update Posted (Actual): December 11, 2025
• Last Update Submitted That Met QC Criteria: November 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Schizophrenia
• Additional Relevant MeSH Terms: Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Schizophrenia; SEP-363856
• Other Study ID Numbers: SEP361-308

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