The study design includes a screening period, a 12-week treatment period, and a follow-up period. Eligible patients will be randomly assigned, under double-blind conditions, to receive the following study drug treatments in a 1:1:1 ratio during the double-blind treatment period: Risperidone ISM® 75 mg, Risperidone ISM® 100 mg, or placebo. The IM study drug (double-blind active Risperidone ISM® or placebo) will be administered in a deltoid or gluteal muscle for a total of 3 times, once every 4 weeks, during the 12-week treatment period.~If indicated for an individual patient, prohibited medications may be washed out during the screening period. Patients who have never taken Risperidone must have a brief trial of oral Risperidone in order to ensure a lack of any clinically significant hypersensitivity reactions before the first dose of the study drug is administered.~Efficacy will be assessed by describing changes in scores on standard psychiatric assessment tools at each visit. Safety assessments will also be conducted at each visit.~The primary objective of this study is the following:~• To evaluate the efficacy of Risperidone ISM as compared with that of placebo in the treatment of patients with acute exacerbation of schizophrenia~The secondary objectives of this study are the following:~To characterize safety and tolerability of Risperidone ISM as compared with that of placebo in patients with acute exacerbation of schizophrenia~To quantify healthcare resource utilization (HRU), health-related quality of life (HRQL), and social functioning in patients treated with Risperidone ISM versus placebo for an acute exacerbation of schizophrenia~To explore pharmacokinetic characteristics of Risperidone ISM and associations with efficacy~Patients who complete planned double-blind study drug treatments and study evaluations may be eligible to participate in an optional long-term extension segment of the study in which treatment with open-label Risperidone ISM 75 or 100 mg (randomly assigned) would begin immediately; for patients who do not participate in the extension segment, a safety follow-up phone contact will occur after the end-of-treatment visit.~In addition to patients continuing from the double-blind segment of the study (rollover patients), patients not previously enrolled in the study (de novo patients) may be eligible to enter the long-term extension segment of the study. These patients will be evaluated for eligibility at a screening visit and, if eligible, will be allocated to receive either 75 or 100 mg Risperidone ISM every 4 weeks for approximately 12 months.
This is a multicenter, randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of intramuscular (IM) injections of Risperidone ISM® (75 or 100 mg) or placebo, in patients with acute exacerbation of schizophrenia.