Safety, Tolerability, and Pharmacokinetics of Switching From Oral Risperidone to Risperidone Implant

Inclusion Criteria

• Adult patients 18-70 years of age of both sexes diagnosed with schizophrenia or schizoaffective disorder according to Diagnostic and Statistical Manual (DSM)-V who have been stable on oral risperidone (2mg-3mg) for at least 2 weeks.
• Patient (and/or a patient's authorized legal representative) has provided written informed consent
• Patient meets the following criteria:
• Outpatient status
• PANSS Total Score ≤ 80 at screening.
• A score of ≤ 4 on the following PANSS items:

i. Conceptual disorganization ii. Suspiciousness iii. Hallucinatory behavior iv. Unusual thought content v. Hostility d. Clinical Global Impression Scale (CGI-S) ≤ 4 (moderately ill)\Lack of clinically significant suicidal ideation or behavior; Columbia Suicide Severity Rating Scale (C-SSRS) score type of 4-5 require evaluation by mental health professional to ensure patient safety in study

• Body Mass Index (BMI) within the range of 18.5 to 40.0 kg/m2 (inclusive);
• Ability to understand the nature and objectives of the trial, including risks and adverse events, and be able to read, review and sign the informed consent document prior to conduct of any study procedures;
• Willing and able to comply with the requirements of the study protocol; including willingness to visit the clinical facility for all outpatient visits and confinement periods;
• Have suitable venous access for blood sampling.
• Patient is assessed by the Investigator to be symptomatically stable with regard to pre-existing medical conditions as evidenced by medical history, non-clinically significant findings on physical examination, vital signs, clinical laboratory evaluations (hematology, serum chemistries, and urinalysis) or 12-lead electrocardiogram (ECG). Subjects may continue on their current prescribed medication regimens to control pre-existing medical and psychiatric conditions (other than schizophrenia) including the use of prescribed PRN medications.

Exclusion Criteria

• PANSS score at baseline is ≥ 20% change from screening.
• Hospitalized or required acute crisis intervention for symptom exacerbation in the 60 days prior to admission as determined by the Investigator
• Patient has a history of suicide attempt in the last year, or in the opinion of the investigator is currently at imminent risk of suicide.
• Patient experiencing acute depressive symptoms within the past 30 days, according to the Investigator's opinion, that required treatment with an antidepressant
• 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 (Alanine transaminase (ALT) /aspartate aminotransferase (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 neuroleptic malignant syndrome (NMS)
• Electroconvulsive therapy within 6 months of admission
• Requires current use of agents that are strong inhibitors and inducers of cytochrome P450;
• Known hypersensitivity or allergy to lidocaine or any local anesthetic agent of the amide type (local anesthetic used during implant and explant procedures);
• Presence of clinically significant skin disorders (such as, but not limited to, skin cancer, psoriasis, eczema, or atopic dermatitis), evidence of recent sunburn, scar tissue, tattoo, open sore, body piercing or branding at the intended implantation site that would interfere with the implantation procedure or interfere with implant site assessments as determined by the investigator;
• History of clinically significant hypersensitivity or allergic reactions;
• Known allergy or hypersensitivity to para-aminobenzoic acid (PABA);
• Known allergy or hypersensitivity to parabens, local anesthetics of the ester type, and sulfa drugs including antibiotics and thiazide diuretics;