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

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.

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.

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.