To evaluate the pharmacokinetics (PK), tolerability, and safety of brexpiprazole QW formulation administered as single and multiple doses in patients with schizophrenia.

A multi-center, open-label clinical pharmacology trial to investigate the PK, tolerability, and safety of brexpiprazole QW formulation administered as single and multiple doses.

The trial comprises the single-dose period (Cohort 1) and the multiple-dose period (Cohort 2). The dose used in the multiple-dose period (Cohort 2) will be determined based on plasma drug concentrations obtained in the single-dose period (Cohort 1).

Inclusion Criteria:

1. Patients with a diagnosis of schizophrenia based on the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5)
2. Patients capable of staying at the trial site from the day before investigational medicinal product (IMP) administration to the 8th day following IMP administration in both Period 1 and Period 2
3. Patients with a body mass index [BMI = body weight (kg)/height (m)2] of 18.5 or higher and lower than 35.0 at screening
4. Persons who provide written informed consent before commencement of any trial-related procedures and whom the investigator or subinvestigator judges to be capable of following all the conditions of this trial
5. Patients who, in the judgement of the investigator or subinvestigator, have stable psychotic symptoms maintained by administration of an antipsychotic (other than clozapine) within the dosing range indicated separately, before commencement of investigational medicinal product (IMP) administration"

Exclusion Criteria:

1. Patients with a diagnosis of a concurrent mental disorder besides schizophrenia (schizoaffective disorder, major depressive disorder, bipolar I disorder, bipolar II disorder, general anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder, dementia or mild neurocognitive disorder, personality disorder, etc) based on the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) (However, this exclusion does not apply to caffeine- or tobacco-related disorders)
2. Patients who fail to meet the specified requisite washout periods for the prohibited concomitant drugs and foods before commencement of IMP administration, or patients who are anticipated to take any of these drugs or foods during the study period
3. Patients who have previously undergone gastrointestinal surgery that could affect pharmacokinetic evaluations
4. Patients who are using clozapine at the time of informed consent
5. Patients who have received electro-convulsive therapy within 60 days before commencement of IMP administration
6. Patients with clinically problematic disorders of the nervous system, liver, kidneys, metabolic system, blood, immune system, cardiovascular system, lungs, or digestive system (However, such patients may be included if the condition is mild or well-controlled and is considered to not affect safety or pharmacokinetic evaluations.)

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.

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 an Otsuka-owned remotely accessible data sharing platform with Python and R analytical software. Research requests should be directed to clinicaltransparency@Otsuka-us.com.

The total number of subjects who participated in Cohort 1 and Cohort 2 was 73. The total age average was calculated from 73 subjects in period 1 of Cohort 1 and Cohort 2.

From the start of IMP administration throughout follow-up period Cohort 1: up to 93 days (Period 1: up to 28 days, Period 2: up to 35 days, Period 3: up to 30 days) Cohort 2: up to 88 days (Period 1: up to 28 days, Period 2: up to 60 days)

Adverse events (AEs) in each participant were monitored in each period of Cohort 1 and 2, with the maximum duration as indicated above, from after the IMP administration in each period until before the IMP administration in the next period (for Cohort 1 period 1-2 and Cohort 2 period 1) or the end of study (for Cohort 1 period 3 and Cohort 2 period 2). AEs were assessed separately in Cohort 1 (period 1-3) and Cohort 2 (period 1-2).