Pharmacokinetics, Safety and Tolerability of Different Formulations and Dose Strengths of Quarterly Risperidone (QUAR) in Patients With Schizophrenia

The study will assess the PK, safety and tolerability of QUAR when administered as a single IM injection, in patients with schizophrenia. The study will be conducted with 3 different dose strengths and up to two formulations. After eligibility confirmation, an oral treatment period follow by a washout period will be performed before QUAR IM administration. The different cohorts will be administered with one of the following dosages of Risperidone QUAR: Cohort 1/2: Formulation 1 or 2. Dose level 1 (Gluteal); Cohort 1a/2a: Formulation 1 or 2. Dose level 2 (Gluteal); Cohort 1b/2b: Formulation 1 or 2. Dose level 3 (Gluteal); Cohort 1c/2c: Formulation 1 or 2. Dose level 3 (Deltoid); The progression to the next cohorts will take place after a clinical safety assessment. Several blood samples for plasma pharmacokinetic (PK) assessments will be obtained pre-dose and post-dose. Safety assessments will be conducted at each pre-specified time points. After assessment of Cohort 1 (formulation 1, Dose Level 1, -gluteus-) progression to the next cohort with same formulation and escalating dose will take place (Cohort 1a -gluteus-). After assessment of Cohort 1a, progression and randomization (gluteus/deltoid) to the next cohorts with same formulation and escalating dose will take place (Cohort 1b -gluteus- and Cohort 1c -deltoid-). In this scenario, none of the Cohorts 2 will be conducted. If the assessment for Cohort 1 is not adequate, none of the subsequent Cohorts 1 (a/b/c) will be conducted and progression to the next cohort (Cohort 2) with different formulation and same level of dose as Cohort 1 will take place (Cohort 2: Formulation 2, Dose Level 1 -gluteus-). After assessment of Cohort 2, progression to the next cohort with same formulation and escalating dose will take place (Cohort 2a -gluteus-). After assessment of Cohort 2a, progression and randomization (gluteus/deltoid) to the next cohorts with same formulation and escalating dose will take place (Cohort 2b -gluteus- and Cohort 2c -deltoid-).