Lurasidone Low-Dose - High-Dose Study Study

Inclusion Criteria

Subject provides written informed consent and is willing and able to comply with the protocol in the opinion of the Investigator.

• Subject is ≥ 18 and ≤ 75 years of age, on the day of signing the informed consent.
• Subject meets DSM-IV-TR criteria for a primary diagnosis of schizophrenia [including disorganized (295.10), paranoid (295.30), undifferentiated (295.90) subtypes] as established by clinical interview (using the DSM-IV-TR as a reference and confirmed using the SCID-CT). The duration of the subject's illness whether treated or untreated must be ≥ 6 months.
• Subject has a PANSS total score ≥ 80 and a PANSS subscale score ≥ 4 (moderate) on 2 or more of the following PANSS subscale items: delusions, conceptual disorganization, hallucinations, and unusual thought content at screening and baseline.
• Subject has a CGI-S score of ≥ 4 at screening and baseline.
• Subject has an acute exacerbation of psychotic symptoms (no longer than 2 months) and marked deterioration of function from baseline (by history) or subject has been hospitalized for the purpose of treating an acute psychotic exacerbation for 2 consecutive weeks or less immediately before screening.

Subjects who have been hospitalized for more than 2 weeks for reasons unrelated to acute exacerbation can be included with concurrence from the Medical Monitor that such hospitalization was for a reason other than acute relapse. For example, subjects in a long term hospital setting who have an acute exacerbation and are transferred to an acute unit are eligible for study entry.

• Subject is not pregnant (must have a negative serum pregnancy test at screening) or nursing (must not be lactating) and is not planning pregnancy within the projected duration of the study.
• Female subject of reproductive potential agrees to remain abstinent or use adequate and reliable contraception throughout the study and for at least 30 days after the last dose of lurasidone has been taken. In the Investigator's judgment, the subject will adhere to this requirement.

Adequate contraception is defined as continuous use of either two barrier methods (eg, condom and spermicide or diaphragm with spermicide) or a hormonal contraceptive. Acceptable hormonal contraceptives include the following: a) contraceptive implant (such as Norplant®) implanted at least 90 days prior to screening; b) injectable contraception (such as medroxyprogesterone acetate injection) given at least 14 days prior to screening; or c) oral contraception taken as directed for at least 30 days prior to screening.

Subjects who are of non-reproductive potential, ie, subject who is surgically sterile, has undergone tubal ligation, or is postmenopausal (defined as at least 12 months of spontaneous amenorrhea or between 6 and 12 months of spontaneous amenorrhea with follicle stimulating hormone (FSH) concentrations within postmenopausal range as determined by laboratory analysis) are not required to remain abstinent or use adequate contraception.

• Subject is able and agrees to remain off prior antipsychotic medication for the duration of the study
• Subject has had a stable living arrangement at the time of screening and agrees to return to a similar living arrangement after discharge. This criterion is not meant to exclude subjects who have temporarily left a stable living arrangement (eg, due to psychosis). Such subjects remain eligible to participate in this protocol. Chronically homeless subjects should not be enrolled.
• Subject is in good physical health on the basis of medical history, physical examination, and laboratory screening.
• Subject who requires concomitant medication treatment with the following agents may be included if they have been on stable doses (ie, minor adjustments only) for the specified times: 1) oral hypoglycemics must be stable for at least 30 days prior to screening, 2) antihypertensive agents must be stable for at least 30 days prior to screening, and 3) thyroid hormon