Study in Stabilized Schizophrenic Patients to Evaluate the Pharmacokinetics of Risperidone and 9-Hydroxy (OH)-Risperidone When Risperidone is Administered From a Polyurethane Implant

The study will be a 6-month, open-label, study in approximately 50 stable subjects diagnosed with schizophrenia or schizoaffective disorder to evaluate the safety, tolerability, and pharmacokinetics of Risperidone and 9-OH-Risperidone following implantation of two or three, 300 mg Risperidone Implants.

Subjects who are diagnosed with schizophrenia or schizoaffective disorder according to DSM-V and are stable on a daily 4 mg oral dose of Risperidone for at least 8 weeks will be recruited into the study.

Subjects stable on a 4 mg oral dose of Risperidone will be implanted with two or three, 300 mg, Risperidone Implants. All implants will be placed in the inner aspect of the upper arm. Plasma concentrations of Risperidone and the active moiety will be measured prior to placement of the Risperidone Implants, throughout the implantation period, and after re-converting to oral Risperidone following the removal of the Risperidone Implants.

Inclusion criteria

• Subject (and/or a subject's authorized legal representative) has provided written informed consent
• Patient meets the following criteria:

• Outpatient status
• PANSS Total Score ≤ 80 at screening and if PANSS score at baseline is ≥ 20% change from screening, the patients cannot participate in the study.
• A score of ≤ 3 on the following PANSS items:

• Conceptual disorganization
• Suspiciousness
• Hallucinatory behavior
• Unusual thought content
• Subject is male or female between 18 to 60 years of age
• Subject has a diagnosis of schizophrenia or schizoaffective disorder according to Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-V) criteria

Exclusion criteria

• Hospitalized or required acute crisis intervention for symptom exacerbation in the 60 days prior to admission as determined by the Investigator
• Subject has a history of suicide attempt in the last year, or in the opinion of the investigator is currently at imminent risk of suicide
• Has a current or recent (within 12 months) DSM-V diagnosis of moderate or severe substance use disorder (except for tobacco use disorder) or has a positive urine drug screen for prohibited substances at screening.
• Have impaired hepatic (ALT/AST >1.5 times higher than the upper limit of normal) or renal function (eGFR<50 mL/min)
• Previously defined hypersensitivity to Risperidone
• History of neuromalignant syndrome (NMS)
• Electroconvulsive therapy within 6 months of admission
• Requires current use of agents that are strong inhibitors and inducers of cytochrome P450 2D6