Study of the Effectiveness of Three Different Doses of OPC-34712 in the Treatment of Adults With Acute 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.

Inclusion Criteria:

1. Male or female subjects between 18 and 65 years of age, with a diagnosis of
schizophrenia, as defined by the Diagnostic and Statistical Manual of Mental
Disorders (DSM-IV-TR) criteria

2. Subjects who have been recently hospitalized or who would benefit from
hospitalization for an acute relapse of schizophrenia

3. Subjects experiencing an acute exacerbation of psychotic symptoms

4. Other protocol specific inclusion criteria may apply

Exclusion Criteria:

1. Females who are breast-feeding and/or who have a positive pregnancy test result prior
to receiving study drug

2. Subjects with a current DSM-IV-TR Axis I diagnosis of:

- Schizoaffective disorder

- Major depressive disorder (MDD)

- Bipolar disorder

- Delirium, dementia, amnestic or other cognitive disorder

- Borderline, paranoid, histrionic, schizotypal, schizoid or antisocial
personality disorder

3. Subjects presenting with a first episode of schizophrenia

4. Other protocol specific exclusion criteria may apply