A Randomized, Active-controlled, Double-blind, Parallel-Goup Study of the Efficacy and Safety of Extended Release(ER) Paliperidone in the Treatment of Schizophrenia

Overview

This is a randomized (patients are assigned different treatments based on chance), double-blind (neither the patient nor the physician knows whether drug or placebo is being taken, or at what dosage), active-controlled, flexible-dose, parallel group, multicenter study. The study consists of a screening phase, a double-blind treatment phase (6 weeks) and a safety follow-up phase (1 week). The patients in this study will be randomized to 1 of 2 treatment groups to receive extended release OROS paliperidone or Olanzapine once daily for the 6-week double-blind treatment phase. Randomization will occur in a ratio of 1 (extended release OROS paliperidone) to 1 (Olanzapine). Patients must be hospitalized at least 14 days after entry. Those who receive extended release OROS paliperidone will start at a dosage of 6 mg taken daily, dose may be titrated up by 3mg/day every 7 days, or down rapidly based on the balance of efficacy (effectiveness of drug) and safety/tolerability assessed by the investigator. After the initial 7 days, dose could be flexible within 3-12mg/day. Those who receive olanzapine will start at a dosage of 5mg taken daily, dose may be titrated up by 5mg/day every 7 days, or down rapidly based on the balance of efficacy and safety/tolerability assessed by the investigator. After the initial 7 days, dose could be flexible within 5-15mg/day. Efficacy parameters include Positive and Negative Symptom Scale (PANSS) score, Clinical Global Impression-Severity (CGI-S) and Personal and Social Performance (PSP) score per assessment visit. The primary efficacy is the change in PANSS from baseline to the last post-randomization assessment. Safety assessments include the adverse events, changes in physical examination, vital signs, laboratory tests at pretreatment and posttreatment.

The study hypothesis is that the effect of extended release OROS paliperidone is not worse than that of Olanzapine in the treatment of schizophrenia as measured by the change in PANSS from baseline to the last post-randomization assessment. A flexible dose range is used in this study. The flexible dose of paliperidone is ranged from 3 to 12mg/day. The flexible dose of olanzapine is ranged from 5-15mg/day.The study medication is capsulized to maintain blind. Study medication must be taken orally once daily before 10 AM with or without food in a consistent manner throughout the study. Medication can not be chewed, divided, dissolved, or crushed. Treatment duration is 6 week each subject.