Efficacy, Safety, and Tolerability of Brexpiprazole (OPC-34712) as Maintenance Treatment in Adults With Schizophrenia

The purpose of this study is to evaluate the efficacy of brexpiprazole compared with placebo as maintenance treatment in adults with schizophrenia.

Schizophrenia is a severely debilitating mental illness that affects approximately 1% of the world population. Hallucinations and delusions are the most striking characteristic positive symptoms of schizophrenia; however, more subtle negative symptoms (eg, social withdrawal and lack of emotion, energy, and motivation) may also be present. The first antipsychotics developed for the treatment of schizophrenia were effective against positive symptoms, but showed little efficacy for negative symptoms and were also associated with a high incidence of side effects. Second generation antipsychotics, represent a significant advancement in the treatment of psychotic disorders because they are effective and at the same time exhibit fewer side effects than first generation antipsychotics. Although generally safer than first generation antipsychotics, the second-generation antipsychotics are not devoid of undesirable side effects such as Hyperprolactinemia and weight gain. In addition, the safety of these drugs vary considerably.

Eligibility Criteria:
Inclusion Criteria:

* Patients age 18 years or older to less than 65 years, inclusive (at time of informed consent)
* Subjects with a current diagnosis of schizophrenia, as defined by DSM-IV-TR criteria and a history of the illness for at least three years prior to screening (as per subject, family, healthcare provider, or by previous medical records).
* Subjects with a stable living environment, as demonstrated by the ability to provide contact information for themselves and/or family/friend(s)/caregiver(s).
* Subjects who showed previous response to antipsychotic treatment in the past year.
* Subjects who are currently treated with oral or depot antipsychotics other than clozapine or who have had a recent lapse in antipsychotic treatment requiring chronic treatment with antipsychotic medication for stabilization.
* Subjects who are experiencing a current acute exacerbation of psychotic symptoms requiring stabilization
* Subjects with a history of relapse and/or exacerbation of symptoms when they are not receiving antipsychotic treatment.

Exclusion Criteria:

* Female patients who are breastfeeding or who have a positive pregnancy test (urine) result prior to receiving investigational medicinal product
* Patients presenting a first episode of schizophrenia based on the clinical judgment of the investigator
* Patients who are diagnosed with a disease other than schizophrenia (schizoaffective disorder, major depressive disorder, bipolar disorder, posttraumatic stress disorder, anxiety disorder, delirium, dementia, amnesia, or other cognitive disorder) based on current DSM-IV-TR Axis Ι criteria, or who are diagnosed with a personality disorder (borderline, paranoid, histrionic, schizotypal, schizoid, or antisocial)
* Subjects experiencing acute depressive symptoms within the past 30 days
* Subjects with schizophrenia who are considered resistant/refractory to antipsychotic treatment by history
* Subjects with a significant risk of violent behavior; who represent a risk of committing suicide
* Subjects with clinically significant tardive dyskinesia
* Subjects currently treated with insulin for diabetes.