Evaluation of Effectiveness of Risperdal® Consta® Compared to Abilify® Over a Two-year Period in Patients With Schizophrenia

Although many patients with schizophrenia 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 of antipsychotics may eliminate the need for daily medication and enhance patient compliance with the treatment regimen. The purpose of this trial is to evaluate the long-term effectiveness of Risperdal® Consta®, a long-acting injectable antipsychotic medication, versus Abilify®, an oral antipsychotic medication in patients with schizophrenia. The study will include patients, who in the investigator's opinion may benefit from a change in their current antipsychotic medication due to insufficient effectiveness, side effects or difficulty in adhering to a daily dose regimen. This is an open-label, randomized study in which patients will have an equal chance of receiving treatment for up to 2 years with Risperdal® Consta®, administered in the muscles near the hip every 2 weeks, or Abilify®, taken orally once daily. The initial dose and subsequent dose of study drug will be determined by the investigator. The patient's current oral antipsychotic medication will be decreased over the first four weeks of the study and discontinued. During the study, investigators may adjust the dose of study drug or add new antipsychotic medications to treat worsening psychotic symptoms. Patients may continue on or have added, antidepressants, mood stabilizers (except carbamazepine), sedative hypnotics, or anxiolytic medications during the study. Patients will return to the doctor's office every two weeks to receive an injection of Risperdal® Consta® or another supply of Abilify®. During certain visits, patients will be asked questions which will help the investigator determine the severity of the patient's illness, how well the study drug is working, quality of life, reasoning, memory, judgement and perception and side effects that may be associated with schizophrenia or treatment. Safety evaluations include the incidence of adverse events during the study, vital signs and clinical laboratory tests (both blood and urine). The study hypothesis is that Risperdal® Consta® is superior to Abilify® in the long-term treatment of subjects with schizophrenia as measured by time to relapse and time in remission. Treatment with Risperdal® Consta® (administered in the muscle every 2 weeks) at a dose of 25, 37.5 or 50 mg or Abilify® (administered orally daily) at a dose of 10-30 mg for 2 years. Investigators will determine the starting dose and may adjust the dosage of study drug during the study according to symptoms and treatment response.