20110165: Study to Evaluate the Effect of AMG 747 on Schizophrenia Negative Symptoms (Study 165)

Inclusion Criteria: * Diagnosis of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) schizophrenia * Total score on the PANSS Marder Negative Symptom Factor Scale (NSFS) ≥ 20 * Total score on the PANSS Marder Positive Symptom Factor Scale (PSFS) ≤ 30 * Receiving stable antipsychotic therapy for at least 8 weeks prior to screening * Receiving a stable dose of other psychotropic agents for at least 8 weeks prior to screening * Subject has had a stable residence or living arrangement for at least 8 weeks prior to screening and the residence or living arrangement is not anticipated to change for the duration of the study * The subject or subject's legally acceptable representative has provided informed consent. Exclusion Criteria: * Current schizoaffective or bipolar disorder, panic disorder, obsessive compulsive disorder, evidence of mental retardation by history or clinical examination or known premorbid IQ ≤ 70 * Clinically significant suicidal ideation or suicide attempts, assaultive behavior or marked changes in mood within the 8 weeks prior to screening, or currently endorsing suicidal ideation in clinical exam * Substance abuse (with the exception of nicotine or caffeine abuse) within the 8 weeks prior to screening, or during screening * Substance dependence (with the exception of nicotine or caffeine dependence) within the 6 months prior to screening, or during screening * Planning to initiate a smoking cessation therapy or otherwise substantially modify nicotine use during the study * Positive urine drug test for substances of abuse (with the exception of positive screens for prescribed agents such as benzodiazepines). * Other criteria may apply