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Pimavanserin

Phase 3

Neuropsychiatric Symptoms Related to Neurodegenerative Disease | Small molecule | Other |ACADIA Pharmaceuticals Inc.|Last Updated: Aug 24, 2025

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Trial Design
RandomizedDouble-BlindPLACEBO_CONTROLLEDDMC
Total Trials2
Total Enrollment1,379
FDA Designations
No designations recorded
Clinical trial landscape

Pimavanserin · 18 trials · 10 indications

Phase 3 10Phase 2 8
NCT04531982Efficacy and Safety of Pimavanserin as Adjunctive Treatment for the Negative Symptoms of SchizophreniaSchizophrenia
COMPLETED454 Analytics
NCT03968159Adjunctive Pimavanserin in Subjects With Major Depressive Disorder and Inadequate Response to Antidepressant TreatmentAdjunctive Treatment of Major Depressive Disorder
COMPLETED298 Analytics
NCT03623321Extension Study of Pimavanserin in Adult Subjects With Neuropsychiatric Symptoms Related to Neurodegenerative DiseaseNeuropsychiatric Symptoms Related to Neurodegenerative Disease
COMPLETED595 Analytics
NCT03575052A Safety Study of Pimavanserin in Adult and Elderly Subjects Experiencing Neuropsychiatric Symptoms Related to Neurodegenerative DiseaseNeuropsychiatric Symptoms Related to Neurodegenerative Disease
COMPLETED784 Analytics
NCT03325556Relapse Prevention Study of Pimavanserin in Dementia-related PsychosisDementia-related Psychosis
COMPLETED392 Analytics
NCT02970292Efficacy and Safety of Adjunctive Pimavanserin for the Treatment of Schizophrenia (ENHANCE-1)Schizophrenia
COMPLETED396 Analytics
NCT01174004A Study of the Safety and Efficacy of Pimavanserin in Patients With Parkinson's Disease PsychosisParkinson's Disease Psychosis
COMPLETED199 Analytics
NCT00658567A Study of Safety and Efficacy of Pimavanserin (ACP-103) in Patients With Parkinson's Disease PsychosisParkinson's Disease Psychosis
COMPLETED123 Analytics
NCT00550238A Study of the Safety and Tolerability of Pimavanserin (ACP-103) in Patients With Parkinson's Disease PsychosisParkinson's Disease Psychosis
COMPLETED459 Analytics
NCT00477672A Study of the Safety and Efficacy of Pimavanserin (ACP-103) in Patients With Parkinson's Disease PsychosisParkinson's Disease Psychosis
COMPLETED298 Analytics
PHASE3COMPLETED
Efficacy and Safety of Pimavanserin as Adjunctive Treatment for the Negative Symptoms of Schizophrenia
SchizophreniaUnlock trial analytics
PHASE3COMPLETED
Adjunctive Pimavanserin in Subjects With Major Depressive Disorder and Inadequate Response to Antidepressant Treatment
Adjunctive Treatment of Major Depressive DisorderUnlock trial analytics
PHASE3COMPLETED
Extension Study of Pimavanserin in Adult Subjects With Neuropsychiatric Symptoms Related to Neurodegenerative Disease
Neuropsychiatric Symptoms Related to Neurodegenerative DiseaseUnlock trial analytics
PHASE3COMPLETED
A Safety Study of Pimavanserin in Adult and Elderly Subjects Experiencing Neuropsychiatric Symptoms Related to Neurodegenerative Disease
Neuropsychiatric Symptoms Related to Neurodegenerative DiseaseUnlock trial analytics
PHASE3COMPLETED
Relapse Prevention Study of Pimavanserin in Dementia-related Psychosis
Dementia-related PsychosisUnlock trial analytics
PHASE3COMPLETED
Efficacy and Safety of Adjunctive Pimavanserin for the Treatment of Schizophrenia (ENHANCE-1)
SchizophreniaUnlock trial analytics
PHASE3COMPLETED
A Study of the Safety and Efficacy of Pimavanserin in Patients With Parkinson's Disease Psychosis
Parkinson's Disease PsychosisUnlock trial analytics
PHASE3COMPLETED
A Study of Safety and Efficacy of Pimavanserin (ACP-103) in Patients With Parkinson's Disease Psychosis
Parkinson's Disease PsychosisUnlock trial analytics
PHASE3COMPLETED
A Study of the Safety and Tolerability of Pimavanserin (ACP-103) in Patients With Parkinson's Disease Psychosis
Parkinson's Disease PsychosisUnlock trial analytics
PHASE3COMPLETED
A Study of the Safety and Efficacy of Pimavanserin (ACP-103) in Patients With Parkinson's Disease Psychosis
Parkinson's Disease PsychosisUnlock trial analytics
Study Endpoints
Primary Endpoints
Negative Symptom Assessment-16 (NSA-16) Total Score - Change From Baseline to Week 26
26 Weeks Treatment Duration

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.

Change From Baseline to Week 5 in Hamilton Depression Scale (17 Items) (HAMD-17) Total Score
Baseline, Week 5

The HAMD-17 consists of 8 items with a score on a 3 point scale and 9 items with a score on a 5 point scale. The total score ranging from 0 to 52 will be calculated as the sum of the scores for all 17 items. Higher total scores denote more severe depression.

Treatment-emergent Adverse Events (TEAEs)
Treatment period and Follow-up period: 56 weeks

Number (%) of patients experiencing at least one TEAE

Time From Randomization to Relapse in the Double-blind (DB) Period
From randomization in the DB period through 26 weeks

The time from randomization to relapse in the DB period was compared between treatment groups using a Cox regression model. The treatment effect was measured by the hazard ratio (HR). Relapse was defined as (1) ≥30% increase in SAPS-H+D total score from DB baseline (BL) and CGI-I score ≥6 relative to DB BL, (2) treatment with antipsychotic for dementia-related delusions/hallucinations, (3) treatment/study discontinuation due to lack of efficacy, and/or (4) hospitalization for worsening dementia-related psychosis. SAPS-H+D is a 20-item scale; the total score is the sum of the 20 item scores (range 0-100); higher scores denote more severe symptoms. CGI-I is a clinician-rated 7-point scale to rate improvement in hallucinations/delusions relative to BL (range 1-7); higher scores denote less improvement or worsening. A pre-specified IA was conducted after accrual of 40 adjudicated relapse events. The prespecified stopping criterion was met; the study was stopped for efficacy.

Change From Baseline to Week 6 in the Positive and Negative Syndrome Scale (PANSS) Total Score
From baseline to Week 6

The PANSS is a 30-item scale used to evaluate the presence, absence, and severity of schizophrenia symptoms. The 30 items are arranged as 7 positive symptom items (P1 to P7), 7 negative symptom items (N1 to N7), and 16 general psychopathology symptom items (G1 to G16). Items are scored over the past week (7 days) on a 7-point scale ranging from 1 (absent) to 7 (extreme). The PANSS total score can range from a minimum of 30 to a maximum of 210, where a higher score signifies greater severity of schizophrenia symptoms.

Antipsychotic Efficacy
Each study visit (i.e. Days 1, 15, 29 and 43)

Antipsychotic Efficacy was defined as a decrease in the severity and/or frequency of hallucinations and/or delusions. This is measured as the change from baseline (Day 1) to Day 43 in the Scale for the Assessment of Positive Symptoms 9-item sum score for Parkinson's Disease (SAPS-PD). The possible total score is 0 to 45 and a negative change in score indicates improvement. Analysis Method: Mixed Model Repeated Measures (MMRM)

Safety: Number (%) of Patients With Drug-related Treatment-emergent Adverse Events (AEs)
From first to last study drug dose plus 30 days

Number (%) of patients with drug-related treatment-emergent AEs (i.e. AEs reported by the Investigator as possibly, probably, or highly probably related to study drug)

Aggressive Responding on the Taylor Aggression Paradigm (TAP)
The TAP will be done about five (5) hours after administration of pimavanserin and after placebo.

In the TAP, the subject competes against a fictitious opponent in a reaction time game during which the investigator manipulates provocation by having the "opponent" select increasing (mild) electric shock levels (i.e., a physically aggressive threat) which then elicits aggressive responding to the "confederate" when he/she loses a reaction-time task. Subjects can select shock from level 1 to level 9, and to select a "high" (10 level) or a "very high" (20 level) shock. The total number of "High" / "Very High" (10/20) shocks selected for the opponent is the outcome for heightened aggression in this study.

Change From Baseline at Week 6 in Caregiver-rated Aberrant Behavior Checklist Irritability (ABC-I) Subscale Score
6 weeks

The Aberrant Behavior Checklist (ABC) is a caregiver-rated scale comprised of 5 empirically-derived subscales encompassing 58 items that describe various behavior problems. It measures domains of irritability, lethargy/social withdrawal, stereotypic behavior, hyperactivity/noncompliance, and inappropriate speech. ABC-I is one of the subscales and comprises of 15 items. Minimum score is 0, maximum is 45. A score for each item ranges from 0 indicating "not at all a problem" to 3 indicating "the problem is severe in degree". Subscale scores are calculated by summing the items within that subscale. Higher scores indicate greater impairment.

Change From Baseline to Week 8 in HAMD-17 (Hamilton Depression Scale -17 Items) Total Score
From baseline to Week 8

The HAMD-17 is a multiple-item questionnaire to assess the severity of depression, including items of mood, feelings of guilt, suicide ideation, insomnia, agitation or retardation, anxiety, weight loss, and somatic symptoms. Each of the 17 items is scored on a 3- or 5-point scale (depending on the item). The minimum total score is 0; the maximum total score is 52. A higher total score signifies more severe depression.

Treatment Emergent Adverse Events (TEAEs)
52 weeks

Safety and tolerability of pimavanserin after 52 weeks of treatment in patients with probable Alzheimer's disease who have symptoms of agitation and Aggression, in terms of occurrence of TEAEs

Change From Baseline to Week 5 in the HAMD-17 Total Score
Baseline, 5 weeks and 10 weeks during Stage 1 and Stage 2, respectively

The Hamilton Rating Scale for Depression (HAMD-17) is a 17-item scale to assess depression. The HAMD-17 consists of 8 items with a score on a 3 point scale and 9 items with a score on a 5 point scale. Each item is rated from least (0) to most frequent or most severe, as applicable, with highest scores of 2 to 4, depending on the item. Items are summed up to calculate the HAMD-17 total score. The total score ranges from 0 to 52. A higher total score indicates more severe depression.

Change From Baseline to Week 26 in the Negative Symptom Assessment-16 (NSA-16) Total Score
From baseline to Week 26

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.

Number (%) of Patients With Drug-related Treatment-emergent Adverse Events (AEs)
From first to last study drug dose plus 30 days

Number (%) of patients with drug-related treatment-emergent AEs

Secondary Endpoints
Clinical Global Impression of Schizophrenia Scale-Severity (CGI-SCH-S) of Negative Symptoms Score - Change From Baseline to Week 26
26 Weeks Treatment Duration
Change From Baseline to Week 5 in Clinical Global Impression-Severity (CGI-S) Score for Depressive Symptoms
Baseline, 5 weeks
Change From Baseline to Week 5 in Sheehan Disability Scale (SDS) Score
Baseline, 5 weeks
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Study Design & Arms
AllocationRANDOMIZED
MaskingQUADRUPLE
ModelPARALLEL
PurposeTREATMENT
Treatment Arms
ArmTypeDescription
Drug - PimavanserinEXPERIMENTALPimavanserin 34 mg taken as two tablets + background antipsychotic, once daily by mouth
PlaceboPLACEBO_COMPARATORPlacebo + background antipsychotic, taken as two tablets, once daily by mouth
PimavanserinEXPERIMENTALDrug- pimavanserin 34 mg, 20 mg, or 10 mg taken as two tablets + background antipsychotic, once daily by mouth
1EXPERIMENTALpimavanserin tartrate, 40 mg, tablet, once daily by mouth for 6 weeks
2PLACEBO_COMPARATORplacebo, tablet, once daily by mouth for 6 weeks
Pimavanserin tartrate (ACP-103)EXPERIMENTALTablets taken once daily by mouth for as long as ACP-103 is considered to be tolerated and beneficial to subjects
3EXPERIMENTALPimavanserin tartrate (ACP-103), 40 mg, tablet, once daily by mouth, 6 weeks
Pimavanserin low doseEXPERIMENTALPatients aged 5 to 12 years: 10 mg/day pimavanserin Patients aged 13 to 17 years: 20 mg/day pimavanserin Pimavanserin given once daily, as capsule of 10 or 20 mg dose strength, respectively, according to the patient's age
Pimavanserin high doseEXPERIMENTALPatients aged 5 to 12 years: 20 mg/day pimavanserin Patients aged 13 to 17 years: 34 mg/day pimavanserin Pimavanserin given once daily, as capsule of 20 or 34 mg dose strength, respectively, according to the patient's age
Pimavanserin 20 mg OR 34 mg per dayEXPERIMENTAL -
Pimavanserin 34 mg + SSRI/SNRIEXPERIMENTALDrug- pimavanserin, 34 mg, taken as two 17 mg tablets, once daily by mouth All patients continued to receive selective serotonin reuptake inhibitor/serotonin norepinephrine reuptake inhibitor (SSRI/SNRI) antidepressants at a stable dose for the duration of the study.
Placebo + SSRI/SNRIPLACEBO_COMPARATORPlacebo, taken as two tablets, once daily by mouth All patients continued to receive selective serotonin reuptake inhibitor/serotonin norepinephrine reuptake inhibitor (SSRI/SNRI) antidepressants at a stable dose for the duration of the study.
Pimavanserin 40 mgEXPERIMENTALPimavanserin tartrate, 40 mg (two 20 mg tablets), once daily by mouth (equivalent to 34 mg free base pimavanserin)
Interventions
NameTypeDescription
PimavanserinDRUGPimavanserin 34 mg, taken as two blinded 17 mg tablets once daily by mouth
PlaceboDRUGPlacebo, taken as two blinded tablets once daily by mouth
Pimavanserin 34 mgDRUGPimavanserin 34 mg total daily dose, tablets, once daily by mouth
Pimavanserin 20 mgDRUGPimavanserin 20 mg total daily dose, tablets, once daily by mouth
pimavanserin tartrateDRUGpimavanserin tartrate, 40 mg, tablet, once daily by mouth for 6 weeks
Pimavanserin tartrate (ACP-103)DRUG10 mg, tablet, once daily by mouth, for six weeks
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Eligibility Criteria
Age Range18 Years to 55 Years
SexALL
Healthy VolunteersNo
Study Sites102

Inclusion Criteria: * Male or female, ≥18 and ≤55 years of age at the time of Screening * Has a caregiver or some other identified responsible person (e.g., family member, social worker, caseworker, or nurse) considered reliable by the Investigator in providing support to the subject to help ensure...

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Recent Changes (Last 90 Days)
LOWMay 26, 2026NCT05895513primaryCompletionDate: changed
LOWMay 24, 2026NCT05895513studyFirstPostDate: changed