An Efficacy Study of Paliperidone for the Prevention of Relapse in Participants With Schizophrenia

The purpose of this study is to evaluate the efficacy, tolerability and safety of paliperidone extended release (ER) tablets (between 3 to 12 milligram (mg), once a day) in the prevention of relapse in schizophrenia participants.

This is a double-blind (neither physician nor participant knows the name of the assigned drug), randomized (participants are assigned to treatment by a chance), placebo-controlled, and parallel-group study of paliperidone ER tablets. The study will consist of 6 phases: 14 days of screening phase, 8 weeks of open-label run-in phase (participants will be flexibly dosed with paliperidone ER once daily in a dose range of 3 mg to 12 mg), 6 weeks of stabilization phase (participants will continue to receive the fixed dose of paliperidone ER), double-blind (DB) phase of various length (participants will be randomly assigned in a 1:1 ratio to receive either paliperidone ER or placebo and this phase will be completed after 86 relapse events are observed or if the study is positive at the interim analysis), 6 months of open-label extension (participants who experience a relapse event or who remain relapse free for the entire duration of the double-blind phase and participants who are enrolled at the time the study is terminated, will be eligible for this phase. All participants will be treated with paliperidone ER and safety and tolerability information will be collected during this phase) phase and 6 months of follow-up phase (participants who withdraw during the DB phase for any reason other than relapse will be followed for 6 months or until they experience a relapse). Participants' safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Have a diagnosis of schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV)
* Have experienced an acute episode, with a Positive and Negative Syndrome Scale (PANSS) total score between 70 and 120 inclusive, at Screening and Baseline
* Women must be postmenopausal (for at least 1 year), surgically sterile (have had a hysterectomy or bilateral oophorectomy, tubal ligation, or otherwise be incapable of pregnancy), practicing a highly effective method of birth control, if sexually active
* Men must be using a highly effective method of birth control and must not donate sperm during the study and for 3 months after receiving the last dose of study drug
* Be willing and capable to complete the questionnaires and able to take oral medications independently

Exclusion Criteria:

* Has drug dependence diagnosis according to DSM-IV (excluding nicotine and caffeine dependence) within 6 months before screening
* Participants with Crohn's disease and hepatic or renal diseases
* Has had relevant history of any significant and/or unstable cardiovascular, respiratory, neurologic (including seizures or significant cerebrovascular dysfunction), renal, hepatic, endocrine, or immunologic diseases
* Has had history of neuroleptic malignant syndrome (the disorder caused by antipsychotic drugs with symptoms of fever, muscle rigidity and delirium)
* Has had known or suspected Stevens Johnson Syndrome (an immune disease with symptoms of fever, sore throat, ulcers and conjunctivitis) after exposure to phenytoin, carbamazepine, barbiturates, or lamotrigine
* Had been treated with clozapine for treatment refractory or treatment resistant schizophrenia
* Has significant risk of suicide or homicidal behavior, or significant risk of deliberate self harm or harm to others
* Has taken isocarboxazid, phenelzine, selegiline and tranylcypromine within 4 weeks before screening
* Has received electroconvulsive therapy within 60 days before screening