Trial Outcomes & Findings for A Phase 2 Study to Evaluate the Safety and Efficacy of CTP-692 as an Adjunctive Treatment in Adults With Schizophrenia (NCT NCT04158687)

Last Updated: 2023-12-22

Results Overview

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.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

326 participants

Primary outcome timeframe

Baseline, Week 12

Results posted on

2023-12-22

Participant Flow

Participants were enrolled at study centers in the United States from 26 November 2019 to 22 December 2020.

521 participants were screened, out of which 326 participants with schizophrenia who were on a stable dopaminergic antipsychotic medication were enrolled and randomized.

Participant milestones

Participant milestones
Measure	Placebo Participants received CTP-692 matched-placebo powder for oral solution, once daily (QD) for up to 12 weeks.	CTP-692 1 Gram QD Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Overall Study STARTED	81	81	85	79
Overall Study Safety Population	81	81	85	78
Overall Study Efficacy Population	80	81	83	77
Overall Study COMPLETED	64	54	65	66
Overall Study NOT COMPLETED	17	27	20	13

Reasons for withdrawal

Reasons for withdrawal
Measure	Placebo Participants received CTP-692 matched-placebo powder for oral solution, once daily (QD) for up to 12 weeks.	CTP-692 1 Gram QD Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Overall Study Adverse Event	2	3	0	3
Overall Study Lost to Follow-up	5	12	4	5
Overall Study Coronavirus Disease 2019 (COVID-19) Related Reasons	2	3	2	0
Overall Study Non-Compliance with Study Medication	2	2	3	0
Overall Study Investigator Decision	0	0	2	0
Overall Study Protocol Violation	0	2	1	0
Overall Study Withdrawal of Consent by Subject	3	3	4	1
Overall Study Reason not Specified	3	2	4	4

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Placebo n=81 Participants Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 Participants Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=85 Participants Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=78 Participants Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.	Total n=325 Participants Total of all reporting groups
Age, Continuous	42.1 years n=5 Participants	40.8 years n=7 Participants	42.7 years n=5 Participants	40.9 years n=4 Participants	41.6 years n=21 Participants
Sex: Female, Male Female	21 Participants n=5 Participants	25 Participants n=7 Participants	25 Participants n=5 Participants	23 Participants n=4 Participants	94 Participants n=21 Participants
Sex: Female, Male Male	60 Participants n=5 Participants	56 Participants n=7 Participants	60 Participants n=5 Participants	55 Participants n=4 Participants	231 Participants n=21 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	8 Participants n=5 Participants	9 Participants n=7 Participants	9 Participants n=5 Participants	15 Participants n=4 Participants	41 Participants n=21 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	72 Participants n=5 Participants	72 Participants n=7 Participants	76 Participants n=5 Participants	63 Participants n=4 Participants	283 Participants n=21 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	1 Participants n=21 Participants
Race/Ethnicity, Customized Race · American Indian or Alaska Native	2 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	4 Participants n=21 Participants
Race/Ethnicity, Customized Race · Asian	2 Participants n=5 Participants	4 Participants n=7 Participants	1 Participants n=5 Participants	2 Participants n=4 Participants	9 Participants n=21 Participants
Race/Ethnicity, Customized Race · Black or African American	49 Participants n=5 Participants	57 Participants n=7 Participants	57 Participants n=5 Participants	47 Participants n=4 Participants	210 Participants n=21 Participants
Race/Ethnicity, Customized Race · Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	2 Participants n=21 Participants
Race/Ethnicity, Customized Race · White	23 Participants n=5 Participants	18 Participants n=7 Participants	23 Participants n=5 Participants	26 Participants n=4 Participants	90 Participants n=21 Participants
Race/Ethnicity, Customized Race · Other	4 Participants n=5 Participants	1 Participants n=7 Participants	3 Participants n=5 Participants	2 Participants n=4 Participants	10 Participants n=21 Participants

PRIMARY outcome

Timeframe: Baseline, Week 12

Population: Efficacy population included all participants who received the study medication and had at least one available post-baseline PANSS assessment. 'Number of participants analyzed' indicates the number of participants with data available for analysis at the specified timepoint.

Outcome measures

Outcome measures
Measure	Placebo n=80 Participants Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 Participants Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=83 Participants Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=77 Participants Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Change From Baseline in Positive and Negative Syndrome Scale (PANSS) Total Score at Week 12 Baseline	82.1 score on a scale Standard Deviation 8.2	81.2 score on a scale Standard Deviation 8.0	81.6 score on a scale Standard Deviation 7.8	82.9 score on a scale Standard Deviation 8.6
Change From Baseline in Positive and Negative Syndrome Scale (PANSS) Total Score at Week 12 Change From Baseline at Week 12	-14.1 score on a scale Standard Deviation 10.4	-15.9 score on a scale Standard Deviation 10.3	-12.2 score on a scale Standard Deviation 10.3	-11.0 score on a scale Standard Deviation 10.6

SECONDARY outcome

Timeframe: Baseline, 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.

Outcome measures

Outcome measures
Measure	Placebo n=80 Participants Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 Participants Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=83 Participants Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=77 Participants Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Change From Baseline in Clinical Global Impression-Severity (CGI-S) Score at Week 12 Baseline	4.2 score on a scale Standard Deviation 0.5	4.1 score on a scale Standard Deviation 0.5	4.1 score on a scale Standard Deviation 0.5	4.2 score on a scale Standard Deviation 0.6
Change From Baseline in Clinical Global Impression-Severity (CGI-S) Score at Week 12 Change From Baseline at Week 12	-0.8 score on a scale Standard Deviation 0.8	-0.8 score on a scale Standard Deviation 0.9	-0.5 score on a scale Standard Deviation 0.7	-0.5 score on a scale Standard Deviation 0.7

SECONDARY outcome

Timeframe: Baseline, 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.

Outcome measures

Outcome measures
Measure	Placebo n=80 Participants Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 Participants Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=83 Participants Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=77 Participants Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Change From Baseline in Personal and Social Performance (PSP) Scale at Week 12 Baseline	57.5 score on a scale Standard Deviation 10.0	58.7 score on a scale Standard Deviation 8.9	58.4 score on a scale Standard Deviation 9.8	58.0 score on a scale Standard Deviation 9.2
Change From Baseline in Personal and Social Performance (PSP) Scale at Week 12 Change From Baseline at Week 12	4.3 score on a scale Standard Deviation 8.6	4.6 score on a scale Standard Deviation 9.1	3.7 score on a scale Standard Deviation 7.4	2.3 score on a scale Standard Deviation 8.3

Adverse Events

Placebo

Serious events: 0 serious events

Other events: 3 other events

Deaths: 0 deaths

CTP-692 1 Gram QD

Serious events: 1 serious events

Other events: 5 other events

Deaths: 0 deaths

CTP-692 2 Grams QD

Serious events: 0 serious events

Other events: 6 other events

Deaths: 0 deaths

CTP-692 4 Grams QD

Serious events: 1 serious events

Other events: 7 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Placebo n=81 participants at risk Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 participants at risk Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=85 participants at risk Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=78 participants at risk Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Infections and infestations Appendicitis	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.2% 1/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.
Infections and infestations Sepsis	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.2% 1/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.
Injury, poisoning and procedural complications Accidental overdose	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.3% 1/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.
Psychiatric disorders Psychotic disorder	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.3% 1/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.
Surgical and medical procedures Appendicectomy	0.00% 0/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.2% 1/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	0.00% 0/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.

Other adverse events

Other adverse events
Measure	Placebo n=81 participants at risk Participants received CTP-692 matched placebo powder for oral solution, QD for up to 12 weeks.	CTP-692 1 Gram QD n=81 participants at risk Participants received CTP-692 1 gram powder for oral solution, QD for up to 12 weeks.	CTP-692 2 Grams QD n=85 participants at risk Participants received CTP-692 2 grams powder for oral solution, QD for up to 12 weeks.	CTP-692 4 Grams QD n=78 participants at risk Participants received CTP-692 4 grams powder for oral solution, QD for up to 12 weeks.
Gastrointestinal disorders Nausea	1.2% 1/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	1.2% 1/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	3.5% 3/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	5.1% 4/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.
Nervous system disorders Headache	2.5% 2/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	4.9% 4/81 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	3.5% 3/85 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.	5.1% 4/78 • All-cause mortality: Screening up to the last follow-up visit (approximately 18 weeks); Adverse events: From the first dose of study medication up to the last follow-up visit (approximately 13 weeks) All-cause mortality: All randomized participants included all participants who were randomized in the study. Adverse events: Safety population included all participants who received at least one dose of study medication.

Additional Information

Colleen E. Hamilton

Concert Pharmaceuticals, Inc.

Phone: 781-860-0045

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee If an Investigator wants to publish study data or results, the publication or presentation must be provided to Concert for review at least 60 days in advance. If Concert needs to file a patent application prior to publication, the publication can be delayed up to 90 days from Sponsor providing notice to the investigator of such need.
Publication restrictions are in place

Restriction type: OTHER