A Clinical Study to learn if SEP-363856 has physical dependence in adults with schizophrenia. This study will be held in approximately 6 study sites in the United States. It will be accepting male and female participants age 18 years to 65 years. Participation will be up to approximately10 weeks.

This is a double-blind, placebo-controlled, randomized withdrawal study comparing abrupt discontinuation of SEP-363856 (SEP-363856 switched to placebo) to continuous SEP-363856 treatment in male and female adult subjects with schizophrenia.

Inclusion Criteria: (this list is not all inclusive)

• Male or female subject between 18 and 65 years of age (inclusive) at the time of informed consent.
• Subject meets Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for a primary diagnosis of schizophrenia as established by clinical interview (using the DSM-5 as a reference and confirmed using the Structured Clinical Interview for DSM-5, Clinical Trials Version [SCID-CT]).
• Subject must have a Clinical Global Impression-Severity Scale (CGI-S) score ≤ 4 (normal to moderately ill) at Screening and Day 1.
• Subject must have a PANSS total score ≤ 80 at Screening and a score of ≤ 4 on the following PANSS items at Screening: P7 (hostility) and G8 (uncooperativeness).
• Subject has been taking an antipsychotic for at least 6 weeks prior to Screening and has had no change in antipsychotic medication(s) (minor dose adjustments for tolerability purposes may be permitted) for at least 6 weeks prior to Screening.

Exclusion Criteria: (this list is not all inclusive)

• Subject has a DSM-5 diagnosis or presence of symptoms consistent with a current DSM-5 diagnosis other than schizophrenia.
• Subject has attempted suicide within 6 months prior to Screening.
• Subject 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 Columbia Suicide Severity Rating Scale (C-SSRS) at Screening (ie, in the past 1 month) or at any subsequent C-SSRS assessment prior to dosing (ie, since last visit).
• Subject is at significant risk of harming him/herself or others (passive or active) according to the Investigator's judgment.

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.

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.

Otsuka will share data on the Vivli data sharing platform which can be found here: https://vivli.org/ourmember/Otsuka/

double blind