Trial Outcomes & Findings for Efficacy and Safety of Pimavanserin as Adjunctive Treatment for the Negative Symptoms of Schizophrenia (NCT NCT04531982)
NCT ID: NCT04531982
Last Updated: 2025-08-22
Results Overview
The NSA-16 is a semi-structured interview and a validated scale containing 16 items for evaluating negative symptoms of schizophrenia, i.e. the reduction or absence of emotional expression and volitional behaviors normally present in a healthy person. Items are scored based on behaviors during the interview (items 1-4, 6, 7, 9, 11, 15, 16) or previous 7 days (items 5, 8, 10, 12-14) on a 6-point scale from 1 to 6. The NSA-16 total score is the sum of item scores. It can range from 16 to a maximum of 96, with higher scores denoting more severe negative symptoms in schizophrenia.
Recruitment status
COMPLETED
Study phase
PHASE3
Target enrollment
454 participants
Primary outcome timeframe
26 Weeks Treatment Duration
Results posted on
2025-08-22
Participant Flow
Participant milestones
| Measure |
Drug - Pimavanserin
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Overall Study
STARTED
|
227
|
226
|
|
Overall Study
COMPLETED
|
195
|
188
|
|
Overall Study
NOT COMPLETED
|
32
|
38
|
Reasons for withdrawal
| Measure |
Drug - Pimavanserin
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Overall Study
Withdrawal by Subject
|
10
|
11
|
|
Overall Study
Adverse Event
|
6
|
14
|
|
Overall Study
Protocol Violation
|
6
|
9
|
|
Overall Study
Non-compliance with study drug
|
3
|
2
|
|
Overall Study
Use of prohibited medication
|
2
|
0
|
|
Overall Study
Lost to Follow-up
|
0
|
1
|
|
Overall Study
Geopolitical conflict
|
2
|
0
|
|
Overall Study
Lack of Efficacy
|
3
|
1
|
Baseline Characteristics
Efficacy and Safety of Pimavanserin as Adjunctive Treatment for the Negative Symptoms of Schizophrenia
Baseline characteristics by cohort
| Measure |
Drug - Pimavanserin
n=227 Participants
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
n=226 Participants
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
Total
n=453 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
227 Participants
n=5 Participants
|
226 Participants
n=7 Participants
|
453 Participants
n=5 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Age, Continuous
|
36.3 years
STANDARD_DEVIATION 9.61 • n=5 Participants
|
37.5 years
STANDARD_DEVIATION 9.78 • n=7 Participants
|
36.9 years
STANDARD_DEVIATION 9.71 • n=5 Participants
|
|
Sex: Female, Male
Female
|
95 Participants
n=5 Participants
|
90 Participants
n=7 Participants
|
185 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
132 Participants
n=5 Participants
|
136 Participants
n=7 Participants
|
268 Participants
n=5 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
1 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
White
|
225 Participants
n=5 Participants
|
224 Participants
n=7 Participants
|
449 Participants
n=5 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
2 Participants
n=5 Participants
|
1 Participants
n=7 Participants
|
3 Participants
n=5 Participants
|
|
Region of Enrollment
Argentina
|
39 participants
n=5 Participants
|
39 participants
n=7 Participants
|
78 participants
n=5 Participants
|
|
Region of Enrollment
Hungary
|
4 participants
n=5 Participants
|
7 participants
n=7 Participants
|
11 participants
n=5 Participants
|
|
Region of Enrollment
Czechia
|
3 participants
n=5 Participants
|
7 participants
n=7 Participants
|
10 participants
n=5 Participants
|
|
Region of Enrollment
Ukraine
|
23 participants
n=5 Participants
|
21 participants
n=7 Participants
|
44 participants
n=5 Participants
|
|
Region of Enrollment
Poland
|
6 participants
n=5 Participants
|
2 participants
n=7 Participants
|
8 participants
n=5 Participants
|
|
Region of Enrollment
Italy
|
2 participants
n=5 Participants
|
3 participants
n=7 Participants
|
5 participants
n=5 Participants
|
|
Region of Enrollment
Bulgaria
|
70 participants
n=5 Participants
|
74 participants
n=7 Participants
|
144 participants
n=5 Participants
|
|
Region of Enrollment
Lithuania
|
1 participants
n=5 Participants
|
0 participants
n=7 Participants
|
1 participants
n=5 Participants
|
|
Region of Enrollment
Serbia
|
21 participants
n=5 Participants
|
24 participants
n=7 Participants
|
45 participants
n=5 Participants
|
|
Region of Enrollment
Croatia
|
5 participants
n=5 Participants
|
8 participants
n=7 Participants
|
13 participants
n=5 Participants
|
|
Region of Enrollment
Russia
|
43 participants
n=5 Participants
|
34 participants
n=7 Participants
|
77 participants
n=5 Participants
|
|
Region of Enrollment
Spain
|
10 participants
n=5 Participants
|
7 participants
n=7 Participants
|
17 participants
n=5 Participants
|
|
Negative Symptom Assessment-16 (NSA-16)
|
61.3 Score
STANDARD_DEVIATION 8.04 • n=5 Participants
|
60.8 Score
STANDARD_DEVIATION 7.86 • n=7 Participants
|
61.1 Score
STANDARD_DEVIATION 7.95 • n=5 Participants
|
|
CGI-SCH S of negative symptoms score
|
4.8 Score
STANDARD_DEVIATION 0.60 • n=5 Participants
|
4.8 Score
STANDARD_DEVIATION 0.57 • n=7 Participants
|
4.8 Score
STANDARD_DEVIATION 0.58 • n=5 Participants
|
PRIMARY outcome
Timeframe: 26 Weeks Treatment DurationPopulation: Full Analysis Set
The NSA-16 is a semi-structured interview and a validated scale containing 16 items for evaluating negative symptoms of schizophrenia, i.e. the reduction or absence of emotional expression and volitional behaviors normally present in a healthy person. Items are scored based on behaviors during the interview (items 1-4, 6, 7, 9, 11, 15, 16) or previous 7 days (items 5, 8, 10, 12-14) on a 6-point scale from 1 to 6. The NSA-16 total score is the sum of item scores. It can range from 16 to a maximum of 96, with higher scores denoting more severe negative symptoms in schizophrenia.
Outcome measures
| Measure |
Drug - Pimavanserin
n=224 Participants
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
n=222 Participants
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Negative Symptom Assessment-16 (NSA-16) Total Score - Change From Baseline to Week 26
|
-12.14 score on a scale
Standard Deviation 10.29
|
-11.09 score on a scale
Standard Deviation 9.18
|
SECONDARY outcome
Timeframe: 26 Weeks Treatment DurationPopulation: Full Analysis Set
The Clinical Global Impression of Schizophrenia Scale-Severity (CGI-SCH S) is a clinician-rated, 7-point scale to evaluate positive, negative, depressive, cognitive symptoms and overall severity in schizophrenia. For the purpose of this study, only the negative symptoms were evaluated. The score could range from 1 (normal, not ill) to 7 (among the most severely ill).
Outcome measures
| Measure |
Drug - Pimavanserin
n=224 Participants
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
n=222 Participants
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Clinical Global Impression of Schizophrenia Scale-Severity (CGI-SCH-S) of Negative Symptoms Score - Change From Baseline to Week 26
|
-0.88 score on a scale
Standard Deviation 0.91
|
-0.87 score on a scale
Standard Deviation 0.92
|
Adverse Events
Drug - Pimavanserin
Serious events: 2 serious events
Other events: 9 other events
Deaths: 0 deaths
Placebo
Serious events: 7 serious events
Other events: 16 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Drug - Pimavanserin
n=227 participants at risk
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
n=226 participants at risk
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Psychiatric disorders
Schizophrenia
|
0.00%
0/227 • 26 weeks
|
1.8%
4/226 • Number of events 4 • 26 weeks
|
|
Psychiatric disorders
Anxiety
|
0.44%
1/227 • Number of events 1 • 26 weeks
|
0.00%
0/226 • 26 weeks
|
|
Psychiatric disorders
Depression
|
0.44%
1/227 • Number of events 1 • 26 weeks
|
0.00%
0/226 • 26 weeks
|
|
Psychiatric disorders
Irritability
|
0.00%
0/227 • 26 weeks
|
0.44%
1/226 • Number of events 1 • 26 weeks
|
|
Infections and infestations
Abscess limb
|
0.44%
1/227 • Number of events 1 • 26 weeks
|
0.00%
0/226 • 26 weeks
|
|
Infections and infestations
COVID-19
|
0.00%
0/227 • 26 weeks
|
0.44%
1/226 • Number of events 1 • 26 weeks
|
|
Respiratory, thoracic and mediastinal disorders
Acute respiratory failure
|
0.00%
0/227 • 26 weeks
|
0.44%
1/226 • Number of events 1 • 26 weeks
|
Other adverse events
| Measure |
Drug - Pimavanserin
n=227 participants at risk
Pimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
Pimavanserin: Pimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
|
Placebo
n=226 participants at risk
Placebo + background antipsychotic, taken as two tablets, once daily by mouth
Placebo: Placebo, taken as two blinded tablets once daily by mouth
|
|---|---|---|
|
Nervous system disorders
Headache
|
4.0%
9/227 • Number of events 12 • 26 weeks
|
7.1%
16/226 • Number of events 18 • 26 weeks
|
Additional Information
Senior Director, Medical Information
Acadia Pharmaceuticals Inc.
Phone: 8444222342
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place