A Study of Long-acting Injectable Risperidone in the Treatment of Patients With Schizophrenia or Schizoaffective Disorder

Risperidone Depot (Microspheres) in the Treatment of Subjects With Schizophrenia or Schizoaffective Disorder

The purpose of this study is to document the long-term safety and tolerability of risperidone, formulated as a long-acting injectable, in the treatment of patients with schizophrenia or schizoaffective disorder; in addition, to evaluate the long-term effectiveness of long-acting risperidone and its effect on quality of life

Although many schizophrenia patients currently take oral antipsychotic medications, it is estimated that up to 75% of them have difficulty adhering to the daily oral regimen. Long-acting injectable formulations may eliminate the need for daily medication and enhance patient compliance with the treatment regimen. This safety study is an extension of a randomized, double-blind, multicenter, parallel group study that investigates effectiveness and safety of risperidone injected intramuscularly in patients with schizophrenia or schizoaffective disorder. The present open-label study evaluates 3 different doses of a formulation of risperidone injected into the muscle at 2 week intervals for at least 1 year in patients with these conditions. Assessments of effectiveness include the Clinical Global Impression (CGI) overall severity of illness scale. Quality of life will be assessed by the SF-36 Health Survey. Safety evaluations include incidence of adverse events, physical examinations, and evaluations of the injection site, clinical laboratory tests, electrocardiograms (ECGs), and Extrapyramidal Symptom Rating Scale (ESRS), a scale assessing muscle tone, gain, and abnormal movements. Injections every 2 weeks for at least 1 year, beginning at 25milligrams[mg] and increasing to 50mg or 75mg (maximum dose). Dosages may be increased or decreased at investigator's discretion. During the first 3 weeks, risperidone tablets (2mg) once daily to supplement injectable risperidone.

Inclusion Criteria:

• Patients must have completed the double-blind study (RIS-USA-121) or withdrawn from that study for safety reasons or due to worsening of condition as determined by results from the CGI
• diagnosis of schizophrenia or schizoaffective disorder according to criteria of Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DMS IV)
• otherwise healthy on the basis of physical examination, medical history, electrocardiogram, blood biochemistry and hematology tests, and urinalysis.

Exclusion Criteria:

• Known intolerance, sensitivity, serious adverse events, or unresponsiveness to risperidone
• diagnosis of DMS IV Axis I condition other than schizophrenia or schizoaffective disorder
• diagnosis of substance abuse or dependence
• use of psychostimulants or an antipsychotic medication other than risperidone
• known disease of the central nervous system (stroke, Parkinson's Disease, Huntington's Disease, Alzheimer's Disease, cancer)
• pregnant or nursing females, or those lacking adequate contraception.