SchizophreniaPhase 3NCT05741528
An Extension Study to a Clinical Study That Will Continue to Evaluate the Effectiveness and Safety of SEP-363856 in People With Schizophrenia That Switch to SEP-363856 From Their From Their Current Antipsychotic Medication
A Phase 3 study testing SEP-363856 in people with Schizophrenia, run by Otsuka Pharmaceutical Development & Commercialization, Inc. at 16 sites in United States.
Trial summary
An Extension study to a clinical study that will continue to evaluate the effectiveness and safety of SEP-363856 in people with schizophrenia that switch to SEP-363856 from their current antipsychotic medication. This study will accept both male and female participants that have completed study SEP361-308. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Schizophrenia
- What is being tested?
- SEP-363856
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 16 sitesUnited States
- Study dates
- 31 Mar 2023to 23 Sep 2024
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Subject has given written informed consent and privacy authorization prior to participation in the study.
- Subject has completed the Treatment Period of Study SEP361-308.
- Subject has not taken any psychotropic medication other than the study drug, pre-switch antipsychotic and protocol-allowed medications during Study SEP361-308.
- Female subject must have a negative rapid urine pregnancy test at the End of Treatment (EOT) Visit of Study SEP361-308.
Who cannot join
- Subject is suicidal based on the Columbia - Suicide Severity Rating Scale (C-SSRS) assessment at the End of Treatment (EOT) Visit of Study SEP361-308.
- Subject has a clinically significant abnormality including physical examination, vital signs, or ECG finding at the End of Treatment (EOT) Visit of Study SEP361-308.
- Subject has a positive rapid urine drug screen at the EOT Visit of Study SEP361-308.
- Female subject is pregnant or lactating.
Trial locations and contacts
16 sites in 1 country.
16 sites in 1 country
United States16 sites
Research Site
Anaheim, California, 92805
Research Site
Atlanta, Georgia, 30318
Research Site
Atlanta, Georgia, 30331
Research Site
Bellflower, California, 90706
Research Site
Berlin, New Jersey, 08009
Research Site
Charlotte, North Carolina, 28211
Research Site
Chicago, Illinois, 60640
Research Site
Gaithersburg, Maryland, 20877
Research Site
Garden Grove, California, 92845
Research Site
Hickory, North Carolina, 28601
Research Site
Hollywood, Florida, 33021
Research Site
Lemon Grove, California, 91945
Research Site
Miami, Florida, 33122
Research Site
Richardson, Texas, 75080
Research Site
Santee, California, 92071
Research Site
Torrance, California, 90502
About this study
Official title: An Open-label Extension Study to Assess the Safety and Tolerability of SEP-363856 in Subjects With Schizophrenia Switched From Typical or Atypical Antipsychotic Agents
An Extension study to a clinical study that will continue to evaluate the effectiveness and safety of SEP-363856 in people with schizophrenia that switch to SEP-363856 from their current antipsychotic medication. This study will accept both male and female participants that have completed study SEP361-308. This study will be held in approximately 24 study sites in North America. Participation in the study will be approximately up to 25 weeks.
Read the detailed description
This is a 24-week, outpatient, multicenter, flexible-dose, open-label extension study designed to evaluate the long-term safety and tolerability of SEP-363856 (50 to 100 mg/day) for the treatment of subjects with schizophrenia who have completed Study SEP361-308 treatment period, during which they were switched from a previous antipsychotic treatment to SEP-363856.
- Conditions
- Schizophrenia
- Being tested
- SEP-363856
- Keywords
- Schizophrenia
- Medical subject headings
- Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SEP-363856Drug
SEP-363856 tablet
| Study group | Role | What they receive |
|---|---|---|
| SEP-363856 | Experimental | Not described Receives: Drug: SEP-363856 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Adverse Events (AEs)
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product.
Measured: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
Number of Participants With Serious Adverse Events
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product. A serious adverse event is any AE occurring at any dose that results in death, is life-threatening, results in persistent or significant disability/incapacity, requires in-patient hospitalization or prolongation of existing hospitalization, or is a congenital anomaly/birth defect.
Measured: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
Number of Participants With AEs Leading to Discontinuation of Study
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product. AEs leading to discontinuation from the study are those AEs which caused participant to discontinue from the study.
Measured: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Feb 2023
- Study start31 Mar 2023
- Primary completion23 Sep 2024
- Study completion23 Sep 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by Otsuka Pharmaceutical Development & Commercialization, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 75 participants (actual)
Sponsor and investigators
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05741528
- Sponsor's protocol ID
- SEP361-309
- Status last verified
- Aug 2025
- First submitted
- 13 Feb 2023
- Last updated
- 11 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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. Access is provided after a research proposal is submitted and has received approval from the Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension can be granted, when justified, for up to another 12 months.
Study at a glance
From the registry record, last updated by the sponsor on 11 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label Extension Study to Assess the Safety and Tolerability of SEP-363856 in Subjects With Schizophrenia Switched From Typical or Atypical Antipsychotic Agents
- ClinicalTrials.gov ID
- NCT05741528
- Acronym / sponsor ID
- SEP361-309
- Conditions
- Schizophrenia
- Keywords
- Schizophrenia
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 75 participants (actual)
- Lead sponsor
- Otsuka Pharmaceutical Development & Commercialization, Inc.Industry (pharma, biotech, devices)
- Study start
- 31 Mar 2023 (actual)
- Primary completion
- 23 Sep 2024 (actual)
- Study completion
- 23 Sep 2024 (actual)
- First posted
- 23 Feb 2023 (actual)
- Results
- Posted 12 Nov 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
An Extension study to a clinical study that will continue to evaluate the effectiveness and safety of SEP-363856 in people with schizophrenia that switch to SEP-363856 from their current antipsychotic medication. This study will accept both male and female participants that have completed study SEP361-308. This study will be held in approximately 24 study sites in North America. Participation in the study will be approximately up to 25 weeks.
Detailed description
This is a 24-week, outpatient, multicenter, flexible-dose, open-label extension study designed to evaluate the long-term safety and tolerability of SEP-363856 (50 to 100 mg/day) for the treatment of subjects with schizophrenia who have completed Study SEP361-308 treatment period, during which they were switched from a previous antipsychotic treatment to SEP-363856.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| SEP-363856 | Experimental | Drug: SEP-363856 |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Subject has given written informed consent and privacy authorization prior to participation in the study.
- Subject has completed the Treatment Period of Study SEP361-308.
- Subject has not taken any psychotropic medication other than the study drug, pre-switch antipsychotic and protocol-allowed medications during Study SEP361-308.
- Female subject must have a negative rapid urine pregnancy test at the End of Treatment (EOT) Visit of Study SEP361-308.
Key exclusion criteria (4 listed)
- Subject is suicidal based on the Columbia - Suicide Severity Rating Scale (C-SSRS) assessment at the End of Treatment (EOT) Visit of Study SEP361-308.
- Subject has a clinically significant abnormality including physical examination, vital signs, or ECG finding at the End of Treatment (EOT) Visit of Study SEP361-308.
- Subject has a positive rapid urine drug screen at the EOT Visit of Study SEP361-308.
- Female subject is pregnant or lactating.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SEP-363856SEP-363856 tablet | Drug | SEP-363856 |
Primary outcome
Number of Participants With Adverse Events (AEs)
Time frame: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product.
Number of Participants With Serious Adverse Events
Time frame: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product. A serious adverse event is any AE occurring at any dose that results in death, is life-threatening, results in persistent or significant disability/incapacity, requires in-patient hospitalization or prolongation of existing hospitalization, or is a congenital anomaly/birth defect.
Number of Participants With AEs Leading to Discontinuation of Study
Time frame: From first dose of study drug up to end of 1 week follow up period (up to Week 25)
An AE is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease occurring after the administration of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product. AEs leading to discontinuation from the study are those AEs which caused participant to discontinue from the study.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. 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. Access is provided after a research proposal is submitted and has received approval from the Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension can be granted, when justified, for up to another 12 months.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
16 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing SEP-363856 in people with Schizophrenia, run by Otsuka Pharmaceutical Development & Commercialization, Inc. at 16 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 16 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 12 Nov 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Adverse Events (AEs) (time frame: From first dose of study drug up to end of 1 week follow up period (up to Week 25)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Dec 2025.