Prevention of Relapse With Injectable Paliperidone Palmitate Versus Oral Antipsychotics

The purpose of this study is to assess the efficacy (how well the drug works; primarily through the time to relapse) of long-acting injectable paliperidone palmitate compared to treatment as usual with orally administered antipsychotics in monotherapy over 24 months in the treatment of recently diagnosed (1-5 years since diagnosis) schizophrenia.

This is a randomized (study drug assigned by chance), open-label (both physician and patient know the name of the assigned drug), rater-blinded (the person who assesses the condition of the patient does not know the name of the assigned drug), active-controlled, parallel-group, multicenter, prospective international study of paliperidone palmitate versus treatment as usual with oral antipsychotic agents in monotherapy in the prevention of relapse (return of symptoms). Patients who have been recently diagnosed with schizophrenia (within 5 years) and are suffering from a schizophrenic relapse (return of symptoms of schizophrenia) will be enrolled. This study consists of a 2-week initial acute oral treatment phase, followed by a treatment phase (core phase) until relapse or up to maximally 24 months, whichever comes first. Prior to a 2-week oral treatment phase, patients will be randomly (by chance) assigned in a 1:1 ratio to receive treatment with paliperidone palmitate injection (once-monthly) or oral antipsychotic medication (daily). Patients randomized to paliperidone palmitate will first receive oral paliperidone ER once daily for 2 weeks followed by paliperidone palmitate injections at a dose of 150 mg eq. on Day 1, 100 mg eq. on Day 8 both in the deltoid muscle and 75 mg eq. on Day 38 and doses in a dose range of 25 to 150 mg eq. in either the deltoid or the gluteal muscle thereafter. Patients randomized to oral comparator arm will receive oral antipsychotics (haloperidol, paliperidone ER, risperidone, olanzapine, quetiapine or aripiprazole) as per investigator discretion and prescribed according to the label. Total treatment duration is maximally 24 months. During the 24 month treatment phase, investigators will be allowed to flexibly decrease or increase the dose of paliperidone palmitate with one dose level in the range of 25 to 150 mg eq. or the oral antipsychotic in the respective locally approved dose range, all according to the patient's clinical needs. The primary endpoint of the 24-month treatment phase will be the time to relapse. Safety will be monitored by evaluating Adverse Events (AEs), rating of extrapyramidal symptoms (symptoms like abnormal muscle movements, abnormal movements of the tongue or jaw, slow or sustained muscle contractions, muscle spasms, shaking, abnormal movements of the eyes, involuntary muscle contractions, slow movements, or restlessness), vital signs measurements (including heart rate and blood pressure), body weight and physical examination findings. A urine pregnancy test will be performed in females of childbearing potential. Adverse events (unintended, but not necessarily unexpected, results of therapy that can be unpleasant or dangerous), associated concomitant medications, and symptoms of relapse will be recorded as needed.

Eligibility Criteria:
Inclusion Criteria:

* Have been meeting the diagnostic criteria for schizophrenia for 1 to 5 years before screening, and have a history of treatment with antipsychotics
* Have a history of two or more relapses requiring psychiatric hospitalization in the preceding 24 months, which may include the current acute episode
* Experiencing at screening an acute schizophrenic episode with a Positive And Negative Syndrome Scale (PANSS) total score at screening between 70 and 120, inclusive
* Be healthy on the basis of physical examination, medical history and vital signs performed at screening
* Woman must be postmenopausal (for at least 1 year) or surgically sterile or abstinent or be practicing an effective method of birth control, must agree to continue to use the same method of contraception throughout the study and must have a negative urine pregnancy test at screening
* be able to fill out questionnaires
* Men must agree to use a double barrier method of birth control and to not donate sperm during the study and for 3 months after receiving the last dose of study drug

Exclusion Criteria:

* Patients that have never been treated with antipsychotics before
* Treatment resistant patient and/or currently (i.within the last 3 months) treated with clozapine
* Substance dependence within 6 months prior to entry and current intravenous drug use or abuse
* allergies, hypersensitivity, or intolerance to risperidone or paliperidone or excipients
* treatment with a long-acting injectable antipsychotic within three injection cycles prior to screening
* newly started psychotherapy program within the two months preceding the treatment phase baseline
* evidence of clinically significant hepatic, renal, cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances in the past 6 months (as determined by medical history, clinical laboratory or ECG results, or physical examination) that would increase the risk associated with taking study medication or would confound the interpretation of the study
* history or current symptoms of tardive dyskinesia or neuroleptic malignant syndrome
* involuntarily hospitalized patient
* pregnant or breast-feeding females