Toxic Epidermal Necrolysis

The purpose of this study is to evaluate the effect of AMG 747 on negative symptoms of schizophrenia in patients who are stable on current antipsychotic treatment. After a run-in period on their current antipsychotic treatment, patients will be randomized to one of the four treatment arms as add-on therapy for a treatment duration of up to 3 months.

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