Comparison of Paliperidone Palmitate and RISPERDAL CONSTA in Patients With Schizophrenia

• Change in the Positive and Negative Syndrome Scale (PANSS) Total Score for Schizophrenia [ Time Frame: Baseline to the last postrandomization assessment in the double-blind treatment period (approximately 13 weeks) ] [ Designated as safety issue: No ]
  The PANSS scale is used to assess the neuropsychiatric symptoms of schizophrenia. The 30-item PANSS scale provides a total score (sum of the scores of all 30 items) and scores for 3 subscales, the positive subscale (7 items), the negative subscale (7 items),and the general psychopathology subscale (16 items), each item rated on a scale of 1 (absent) to 7 (extreme).
  
  

• The Change From Baseline for the CGI-S Score [ Time Frame: Baseline to the last postrandomization assessment in the double-blind treatment period (approximately 13 weeks)] ] [ Designated as safety issue: No ]
  The CGI-S rating scale is used to rate the severity of a patient's psychotic condition on a 7-point scale ranging from 1 (not ill) to 7 (extremely severe). This scale permits a global evaluation of the patient's condition at a given time. A qualified rater administered the CGI-S.
  
  
• The Change From Baseline in the PSP Score [ Time Frame: Baseline to the last postrandomization assessment in the double-blind treatment period (approximately 13 weeks) ] [ Designated as safety issue: No ]
  The PSP scale is used to assess the degree of dysfunction a patient exhibits over a 7-day period within 4 domains of behavior: socially useful activities, personal and social relationships, self-care, and disturbing and aggressive behavior. The results of the assessment are converted to a numeric score. A score between 71 and 100 indicates a mild degree of difficulty; a score between 31 and 70 indicates a moderate degree of dysfunction, and a patient with a score of 30 or less has functioning so poor he or she requires intensive supervision.
  
  

This is a randomized (patients assigned to treatment groups by chance), double-blind (patient and study staff will not know the treatment assignment) study of paliperidone palmitate compared with RISPERDAL CONSTA (Risperidone Long-Acting Intramuscular Injection) in adult patients with schizophrenia. The total duration of the study will be approximately 14 weeks. For those patients without source documentation of tolerability to oral (by mouth) risperidone or paliperidone Extended Release (ER) tablets, injectable RISPERDAL CONSTA or paliperidone palmitate, or those patients who were not currently taking another antipsychotic, a minimum of 4 days and a maximum of 6 days of oral paliperidone ER treatment at a dosage of 6 mg/day will be administered for tolerability testing before the first injection of double-blind (DB) study drug (paliperidone palmitate or RISPERDAL CONSTA). During the DB period, study drug will be administered to patients as an intramuscular (i.m.) injection. Paliperidone palmitate (PP) 150mg equivalent (eq) (and RISPERDAL CONSTA placebo) at Baseline (BL) (Day 1), 100mg eq at Visit (V) 4 (Day 8), 50 or 100mg eq at V7 (Day 36), and 50,100,or 150mg eq at V9 (Day 64) or RISPERDAL CONSTA (RC) 25mg at V4 and V6 (Day 22), 25 or 37.5mg at V7, and 25, 37.5, or 50mg at V9 will be given as i.m. injections. Patients in the RC group will also take risperidone tablets (1-6 mg/day) at BL for 28 days and be given an injection of PP placebo at BL, V1, V7, and V9.