A Comparative Study of Paliperidone Palmitate and Risperidone Long Acting Injection (LAI) in Participants With Schizophrenia

This is a randomized (assigned by chance), open-label (all people know the identity of the intervention), active-controlled, parallel-group (a medical research study comparing the response in two or more groups of participants receiving different treatments), multicenter (when more than one hospital or medical school team work on a medical research study) comparative study in participants with schizophrenia. This study comprises a screening period of not more than 7 days and a 13-week open-label treatment period. Paliperidone palmitate will be administered as intramuscular injection (injection of a substance into a muscle) of 150 milligram equivalent (mg eq.) at baseline, 100 mg eq. at Day 8, flexible dose on Day 36 (50 or 100 mg eq.) and on Day 64 (50, 100 or 150 mg eq.) depending on investigator's discretion. Risperidone LAI will be administered at a dose of 25 mg at Day 8 and Day 22, flexible dose on Day 36 (25 or 37.5 mg) and Day 64 (25, 37.5, or 50 mg). Dose on Day 50 is the same as Day 36 and dose on Day 78 is the same as Day 64. Participants will receive oral risperidone tablets (1 to 6 mg/day) for the first 4 weeks of the open-label treatment period. Each participant may receive oral risperidone tablets (1 to 2 mg daily) for up to 3 weeks at Day 36 and Day 64 if the dose of risperidone LAI was increased on Day 36 and Day 64. Efficacy will primarily be assessed using the Positive and Negative Syndrome Scale (PANSS). Participants' safety will also be assessed.