A Safety and Pharmacokinetic Study of ER OROS Paliperidone in Pediatric Patients With Schizophrenia, Schizoaffective Disorder, or Schizophreniform Disorder

The current study is designed as a multicenter, open-label, multiple-dose study in children and adolescent patients \>= 10 to \<= 17 years of age with schizophrenia, schizoaffective disorder, or schizophreniform disorder. The study includes 3 dosage groups (0.086, 0.129, and 0.171 mg/kg/day paliperidone ER), which will be studied in a sequential ascending design, so that the safety of the drug can be properly evaluated with a lower dosage before proceeding to the next higher dosage. The 3 dosages are approximately 6, 9, and 12 mg/day in adults. Within each dosage group, patients will be randomly assigned to 1 of 2 pharmacokinetic sampling schedules in a 1:1 ratio. For each dosage group, the study consists of a screening phase (for a maximum of 21 days); a 2-day, single-dose pharmacokinetic and tolerability evaluation phase; a 7-day multiple-dose phase, with evaluation of pharmacokinetics and tolerability; and an end-of-study visit. Following the completion of all patients in a given dosage group, the sponsor will evaluate the safety and tolerability of the treatment, in order to determine whether to proceed to the next higher or lower dosage level. The first group will start at 0.086 mg/kg/day. The hypothesis is that paliperidone ER will be well tolerated in children and adolescent patients with schizophrenia, schizoaffective disorder, or schizophreniform disorder, and will display the expected pharmacokinetic characteristics in this population. Paliperidone ER 0.086, 0.129, and 0.171 mg/kg/day, oral administration, single dose on Day 1 of study followed by once daily dosing on Days 3 to 9.