Study of Paliperidone Palmitate 3 Month and 1 Month Formulations for the Treatment of Patients With Schizophrenia

This is a randomized (the study drug is assigned by chance), double blind (neither physician
nor patient knows the treatment that the patient receives), parallel group (each group of
patients will be treated at the same time), multicenter non-inferiority (the effect of the
new treatment is not worse than that of the comparison treatment) study. A new formulation
of paliperidone palmitate with a 3-month injection interval (PP3M) is being tested for use
as maintenance treatment for subjects with schizophrenia who have been first stabilized on
paliperidone palmitate with a 1-month injection interval (PP1M). The study consists of 3
phases: a screening/washout/tolerability phase (up to 21 days); a 17-week open-label (all
people know the identity of the intervention) stabilization phase (referred to as the
Open-label Phase) and a 48-week fixed dose, randomized, double-blind controlled phase
(referred to as the Double-blind Phase). After completion of the Screening Phase, all
patients will receive PP1M in the Open-label Phase. During this time, flexible dosing will
occur at Weeks 5 and 9. At Week 13 patients are to receive the dose of PP1M that was
administered at Week 9. Patients who are clinically stable at the end of the Open-label
Phase will enter the Double-blind Phase and will be randomly assigned in a 1:1 ratio to
receive fixed doses of PP3M or PP1M.

Inclusion Criteria:

- Patients with schizophrenia for more than 1 year and whose symptoms are worsening in
the opinion of the investigator

- A total score in the Positive and Negative Syndrome Scale (PANSS) between 70 and 120

- Signed informed consent

- Women must not be pregnant, breastfeeding, and if capable of pregnancy must practice
an effective method of birth control

- Men must agree to use a double-barrier method of birth control

- Be medically stable on the basis of clinical laboratory tests, physical examination,
medical history, vital signs, and electrocardiogram (ECG)

Exclusion Criteria:

- A diagnosis other than schizophrenia, e.g., dissociative disorder, bipolar disorder,
major depressive disorder, schizoaffective disorder, schizophreniform disorder,
autistic disorder, primary substance-induced psychotic disorder, dementia-related
psychosis

- Relevant history or current presence of any significant or unstable medical
condition(s) determined to be clinically significant by the Investigator (ie,
obesity, diabetes, heart disease etc)

- A diagnosis of substance dependence within 6 months before screening

- History of neuroleptic malignant syndrome (NMS) or tardive dyskinesia

- Clozapine use in the last 2 months when used for treatment-resistant or
treatment-refractory illness

- Clinically significant findings in biochemistry, hematology, ECG or urinalysis
results

- Any other disease or condition that, in the opinion of the investigator, would make
participation not in the best interest of the patient or that could prevent, limit,
or confound the protocol-specified assessments