A Six-week, Randomized, Double-blind, Placebo-controlled, Parallel Group, Multi-center, Phase II Study

Inclusion Criteria

• •Patient is male or female, 18-65 years of age, inclusive.
• •If female, the patient must be post-menopausal, or if fecund, must be abstinent or practicing an established method of birth control such as hormonal preparations (e.g., oral contraceptive tablets, hormonal implant device, hormone patch, or injectable contraceptive), or intrauterine device \[IUD\], for at least two months prior to screening, and in addition must use a barrier method, e.g., condom, diaphragm, contraceptive foam.
• •Patient is willing and able to provide informed consent, after the nature of the study has been fully explained.
• •Patient is an inpatient or outpatient who has a current DSM-IV-TR diagnosis of schizophrenia, as confirmed by the MINI-Plus.
• •Patient must be experiencing an acute exacerbation of psychosis, with a baseline (Study Day 0) total score on the PANSS greater than '70'.
• •Patient must have a score of '4' ("moderate") or more at baseline on two of the following four PANSS items: delusions, hallucinatory behaviors, conceptual disorganization or suspiciousness/persecution, where at least one of the two items must be either delusions or hallucinatory behaviors, and the total score on the four items must be greater than '17'.
• •Patient must be experiencing an acute exacerbation of psychosis with a total score on the CGI-S of '4' ("moderate") or greater at baseline.
• •Patient is willing to be hospitalized at screening, and willing to remain in the hospital at least 14 days after baseline (through Study Day 14) as clinically indicated, and must be willing to comply with all study related evaluations and procedures through Study Day 42.
• •Patient has a caregiver or an identified responsible person (e.g., family member, social worker, nurse) who will support him/her to ensure compliance with the treatment and outpatient visits.
• •Patient is willing to comply with not taking any prohibited medications during participation in the study.