An Efficacy and Safety Study of Paliperidone Palmitate in Participants With Schizophrenia

This is a randomized (the study drug is assigned by chance), double-blind (neither physician nor participant knows the name of the assigned drug), placebo-controlled (an inactive substance; a pretend treatment \[with no drug in it\] that is compared in a clinical trial with a drug to test if the drug has a real effect), parallel-group (comparing the response in two groups of participants receiving different treatments), fixed-dose, multi-center (when more than one hospital or medical school team work on a medical research study) study of paliperidone palmitate in participants with schizophrenia. The study will consist of 3 periods: an up to 2-week pre-observation (screening) period, a double-blind period from Day 1 (baseline) to Week 13 (end of double-blind period) assessment, and a post-observation period starting after the Week 13 assessment to Week 21. For participants who discontinue the study before the last assessment in Week 13, the post-observation period will start after the discontinuation from double-blind period assessment with follow-up visits at 4, 8, and 12 weeks after the last injection. After completion of the double-blind period (Week 13), discontinuation of double-blind period treatment or withdrawal from the study, participants may receive treatment consistent with the usual standard of care. The total duration of the study will be 21 weeks, including the double-blind and post-observation periods. Participants will be randomly assigned to 1 of 2 treatment groups in a 1:1 ratio (intramuscular injections of either paliperidone palmitate or matching placebo). Injections of paliperidone palmitate or placebo will be given at Day 1 and at Weeks 1, 5, and 9 by a study drug manager and/or injector. For those participants receiving paliperidone palmitate, the Day 1 injection will be 150 milligram equivalent (mg eq.) paliperidone palmitate, followed by 100 mg eq. injections of paliperidone palmitate at Week 1, and 75 mg eq. injections of paliperidone palmitate at Weeks 5 and 9. Participants randomly assigned to placebo will receive injections matching the paliperidone palmitate injections on the same days. Efficacy will be assessed using Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression - Severity (CGI-S). Participant's safety will be monitored throughout the study.