Long-term SEP-363856 treatment for adults with schizophrenia

A Multicenter, Uncontrolled, Open-label Trial to Evaluate the Tolerability, Safety, and Efficacy of Long-term Administration of SEP-363856 in Patients With Schizophrenia

Phase 3 Interventional Otsuka Pharmaceutical Co., Ltd. · NCT07225712

This trial will test whether taking SEP-363856 (75 mg or 100 mg daily) for 52 weeks is safe for adults in Japan who have stable schizophrenia.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorOtsuka Pharmaceutical Co., Ltd. Industry-sponsored
Locations1 site (Fukuoka)
Trial IDNCT07225712 on ClinicalTrials.gov

What this trial studies

This Phase 3 interventional trial gives adult participants with DSM-5 schizophrenia daily SEP-363856 at either 75 mg or 100 mg for 52 weeks to collect long-term safety data. Eligible participants must be clinically stable for at least 8 weeks, have PANSS total ≤80 and CGI-S ≤4, and have had no recent significant antipsychotic changes. The study excludes those with recent psychiatric hospitalization, treatment-resistant illness, or prior clozapine treatment. Safety measures and clinical status will be monitored regularly at the single participating clinic in Fukuoka.

Who should consider this trial

Good fit: Japanese adults aged 18 or older with DSM-5 schizophrenia who have been clinically stable for ≥8 weeks, with PANSS ≤80 and CGI-S ≤4 and no recent antipsychotic changes are the intended participants.

Not a fit: Patients with recent psychiatric hospitalization, treatment-resistant schizophrenia, prior clozapine use, or unstable symptoms are unlikely to benefit from or qualify for this protocol.

Why it matters

Potential benefit: If successful, the drug could become a well-tolerated oral option for long-term maintenance treatment in schizophrenia.

How similar studies have performed: Earlier short-term trials of SEP-363856 showed promising efficacy and tolerability signals, but long-term safety data remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Japanese male or female participants 18 years of age or older at the time of informed consent
* Diagnosed with schizophrenia according to the DSM-5®
* Judged by the investigator to be clinically stable for at least 8 weeks prior to screening
* PANSS total score of 80 or less and CGI-S score 4 or less at both screening and baseline
* No changes in antipsychotic medication for at least 6 weeks before screening (excluding minor dose adjustments for tolerability)

Exclusion Criteria:

* History of psychiatric hospitalization within 8 weeks prior to screening
* Treatment-resistant to antipsychotic therapy (ie, within 1 year to screening, despite administration of two or more marketed antipsychotics at appropriate doses for at least 4 weeks \[28 consecutive days\] in accordance with the package insert, psychiatric symptoms did not improve)
* History of treatment with clozapine
* Unwillingness, before or during the trial period, to comply with the requirements for prior and concomitant medications/therapies as specified in the protocol or use of prohibited medications at screening or baseline as specified in the protocol.

Where this trial is running

Fukuoka

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Schizophrenia
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.