Evaluation of Effectiveness and Safety of Flexible-dose Paliperidone Extended Release in Patients With Schizoaffective Disorder.

The purpose of this study is to measure the effectiveness and assess the safety of different dosages (from 3 mg/day to 12 mg/day) of the antipsychotic paliperidone extended-release (ER) in patients who are experiencing an acute episode of schizoaffective disorder.

Schizophrenia and schizoaffective disorder are closely related in terms of symptoms, coexisting conditions, and genetic risk. In previous studies in patients with schizophrenia, treatment with paliperidone extended-release (ER) improved psychotic symptoms, as well as mood symptoms evaluated by anxiety/depression and hostility/excitement Positive and Negative Symptoms of Schizophrenia (PANSS) factor scores. Therefore, paliperidone ER may also be effective in treating symptoms of schizoaffective disorder. Paliperidone's limited potential for drug-drug interaction is particularly important in this patient population, in which multiple drug therapy is relatively common. This multicenter, double-blind (neither the patient nor the physician knows whether drug or placebo is being taken, or at what dosage), randomized (patients are assigned different treatments based on chance), placebo-controlled, parallel-group study is designed to examine the effectiveness and safety of paliperidone ER in adult patients with schizoaffective disorder who are experiencing an acute episode of this disorder. Patients in the study will be randomly assigned to 1 of 2 groups to receive 6 weeks of oral treatment with flexible dosages of paliperidone ER (3-12 mg/day) or with placebo. The primary efficacy outcome will be the change from baseline to Week 6, or the last post-randomization assessment during double-blind treatment (endpoint), in the PANSS total score. Safety will be assessed by monitoring adverse events, clinical laboratory testing, pregnancy testing, vital signs measurements, physical examination, administration of a 12-lead ECG, movement disorders side effect scales, and the InterSePT Scale for Suicidal Thinking. Patients may also choose to participate in a pharmacogenomic (DNA) analysis. The primary study hypothesis is that flexible-dose paliperidone ER is better than placebo on the change from baseline in the PANSS total score in acutely ill patients with schizoaffective disorder. Patients will receive study drug by mouth for a total of 43 days. Beginning on Day 1, patients will take either placebo or paliperidone ER 6 mg/day. After day 4, dosages may be adjusted, at defined intervals, to a dosage between 3 mg/day and 12 mg/day, inclusive.

Eligibility Criteria:
Inclusion Criteria:

* Diagnostic and Statistical Manual - Fourth Edition (DSM-IV) diagnosis of schizoaffective disorder
* A total Positive and Negative Symptoms of Schizophrenia (PANSS) score of \>= 60
* A score of \>= 16 on Young Mania Rating Scale (YMRS) or a score of \>= 16 on the Hamilton Depression Rating Scale (HAM-D 21)

Exclusion Criteria:

* A primary active mental illness diagnosis other than schizoaffective disorder
* Patients with first episode psychosis
* Active substance dependence within previous 6 months
* Treatment with clozapine within 6 months of randomization
* A history of treatment resistance, defined by failure to respond to 2 adequate trials of antipsychotic medication
* Pregnancy, breast-feeding, or planning to become pregnant