A Phase 2 Study to Evaluate the Safety and Efficacy of CTP-692 as an Adjunctive Treatment in Adults With Schizophrenia

Study Overview
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Brief Summary
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The objective of this study is to assess the safety and efficacy of 3 different doses of CTP-692 administered once daily (QD) for 12 weeks to adult participants with schizophrenia on stable dopaminergic antipsychotic medication.

Official Title
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A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety and Efficacy of CTP-692 as an Adjunctive Treatment in Adult Patients With Schizophrenia

Conditions
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Schizophrenia

Intervention / Treatment
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* Drug: CTP-692
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physician confirmed diagnostic and statistical manual-version 5 (DSM-V5) diagnosis of schizophrenia for the past 2 years Patients with clinically stable schizophrenia with residual symptoms defined as positive and negative syndrome scale (PANSS) total score of 70-110 Patients currently treated with one antipsychotic medication Exclusion Criteria: Patients who, in the opinion of the Investigator, have a history of antipsychotic treatment resistance Patients currently taking clozapine History of meeting DSM-V5 criteria for moderate to severe alcohol or substance use disorder (other than nicotine or caffeine) within the 6 months before the first Screening Visit Patients with positive blood screen for human immunodeficiency virus (HIV) antibody and/or hepatitis B virus surface antigen Patients with history of renal disease or those taking medications to treat renal disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Participants received CTP-692 matched-placebo powder for oral solution, once daily (QD) for up to 12 weeks. | Drug: Placebo<br>* Administered as powder for oral solution.<br>|
| Experimental: CTP-692 1 gram QD<br>Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks. | Drug: CTP-692<br>* Administered as powder for oral solution.<br>|
| Experimental: CTP-692 2 grams QD<br>Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks. | Drug: CTP-692<br>* Administered as powder for oral solution.<br>|
| Experimental: CTP-692 4 grams QD<br>Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks. | Drug: CTP-692<br>* Administered as powder for oral solution.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Positive and Negative Syndrome Scale (PANSS) Total Score at Week 12 | PANSS measures symptom severity in participants with schizophrenia. PANSS includes 30 items (7 items for positive symptoms, 7 items for negative symptoms, and 16 items for general psychopathology symptoms), and each item is rated with 1 to 7 points. The PANSS is scored by summation of ratings across items such that the score ranges are 7 to 49 for each of the Positive and Negative Scales and 16 to 112 for the General Psychopathology Scale. The PANSS total score is a sum of scores from all the 30 items and the scores range from 30 to 210, where a higher score represents more severe symptoms, and lower scores represent a better quality of life in participants with schizophrenia. A negative change from baseline indicates low severity of symptoms. | Baseline, Week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline in Clinical Global Impression-Severity (CGI-S) Score at Week 12 | The CGI-S rating scale is a commonly used measure of symptom severity and treatment response. CGI-S is a 7-point scale that requires the clinician to rate the severity of the patient's illness at the time of assessment and the score ranges from 1 to 7: 0 = not assessed; 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; 7 = among the most extremely ill participants. A higher score represents more severe symptoms. A negative change from baseline indicates low severity of symptoms. | Baseline, Week 12 | 
| Change From Baseline in Personal and Social Performance (PSP) Scale at Week 12 | PSP scale is a measure of the personal and social functioning of participants with psychiatric disorders within four domains: socially useful activities, personal and social relationships, self-care, and disturbing and aggressive behavior. Each domain was assessed on a 6-point scale: 1 = absent, 2 = mild, 3 = manifest, 4 = marked, 5 = severe, and 6 = very severe. The final global score is defined according to a summary instruction table converting four domain scores into a single, overall rating from 1 to 100: 71 to 100 represent mild degree of difficulty; 31 to 70 represent varying degrees of disability, and 1 to 30 represent functioning so poorly as to require intensive supervision. Higher scores represent better personal and social function. A positive change from baseline indicates better personal and social function. | Baseline, Week 12 |