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Irritability Associated With Autism Spectrum DisorderPhase 2/3NCT05523895

Pimavanserin for the Treatment of Irritability Associated With Autism Spectrum Disorder

A Phase 2/3 study testing Pimavanserin in people with Irritability Associated With Autism Spectrum Disorder, run by ACADIA Pharmaceuticals Inc. at 57 sites in 8 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

6-week, randomized, double-blind, fixed-dose, placebo-controlled, parallel group study in children and adolescents (aged 5 to17 years) with autism spectrum disorder (ASD) with irritability, agitation, or self-injurious behaviors to study the efficacy and safety of pimavanserin Read more about this study

Who is it for?
Ages 5 to 17 years
What is being tested?
Pimavanserin
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
237 participants
Where
57 sitesin 8 countries
Study dates
9 Aug 2022to 27 Sep 2024
Phase
Phase 2/3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 5 to 17 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Male or female and 5 through 17 years of age
  • Informed consent prior to the conduct of any study procedures
  • Patients (to the best of his/her ability), parent/legally accepted representative, and designated caregiver (if applicable) are able to understand the nature of the study, follow protocol requirements, and be willing to comply with study drug administration requirements
  • Able to swallow a test placebo capsule without difficulty
  • Meets Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for a primary diagnosis of ASD (APA 2013) and diagnosis is confirmed by the Autism Diagnostic Interview-Revised (ADI-R)
  • Score ≥18 on the Irritability subscale of the Aberrant Behavior Checklist (ABC)
Show all 11Show fewer
  • Score ≥4 (moderate or greater severity) on the Clinical Global Impression-Severity (CGI-S) of irritability score
  • No current comorbid psychiatric disorder other than attention-deficit hyperactivity disorder (ADHD) or anxiety disorder
  • Drug-naïve to antipsychotic treatment (or <2 weeks antipsychotic treatment for any reason), or prior lack of tolerability to adequate dose of any duration of antipsychotic confirmed by caregiver and medical records review
  • If patient is undergoing concurrent behavioral therapy for autism related symptoms or behaviors, this non-pharmacological treatment regimen has been stable for at least 4 weeks, and will be consistent throughout the study
  • For female patients only: unable to become pregnant or agree to use a highly effective non-hormonal method of contraception. Females of childbearing potential must have a negative pregnancy test

Who cannot join

  • Requires treatment with a medication prohibited by the protocol, including concomitant psychotropic drugs targeting irritability, including those used off-label (clonidine, guanfacine, and propranolol; lithium, valproate), medications that prolong the QT interval, and strong cytochrome P450 (CYP) 3A4 enzyme (CYP3A4) inhibitors and inducers
  • Changes in medications or medication doses (for medical and allowed comorbid psychiatric conditions) in the last 4 weeks
  • Any known history of angioedema, serotonin or neuroleptic malignant syndromes, dystonic reaction, or tardive dyskinesia, due to an antipsychotic or psychotropic medication
  • At a significant risk of suicide, or is a danger to self or others
  • At risk of significant violent behavior to the extent that participation would pose an undue risk to other patients, caregivers, or others
  • Positive urine drug test
Show all 21Show fewer
  • Met DSM-5 criteria for substance use disorders within the last 6 months
  • Confirmed genetic disorder associated with ASD, a cognitive and/ or behavioral disturbance or profound intellectual disability (IQ ≤50)
  • History of seizures, unless seizure-free and off epileptic drugs for at least 6 months
  • Any condition that, in the opinion of the Investigator, would interfere with the ability to comply with study instructions, or that might confound the interpretation of the study results or put the subject at undue risk
  • Current evidence, or history within the last 12 weeks, of a serious and/or unstable psychiatric, neurologic, cardiovascular, respiratory, gastrointestinal, renal, hepatic, hematologic, or other medical disorder, including cancer or malignancies
  • Weight <15 kg
  • History or presence on at least one ECG of protocol-defined cardiac conduction abnormalities
  • Known family or personal history or symptoms of long QT syndrome or history of cardiac arrhythmias or risk factors for torsade de pointes and/or sudden death, including symptomatic bradycardia, hypokalemia or hypomagnesemia, and presence of congenital prolongation of the QT interval
  • Any member of the household has suffered from COVID-19 or had a COVID-19 (PCR or immunoglobulin) positive test in the last 4 weeks
  • One or more clinical laboratory test value outside of protocol-defined limits
  • Breastfeeding or lactating, or has a positive pregnancy test result (for patients of childbearing potential)
  • Sensitivity to pimavanserin or any of the excipients
  • Participating in another clinical study of any investigational drug, device, or intervention
  • Participated in greater than 2 interventional pharmaceutical clinical research studies in the last 6 months
  • Additional inclusion/exclusion criteria apply. Subjects will be evaluated at screening to ensure that all criteria for study participation are met.

Trial locations and contacts

57 sites in 8 countries.

57 sites in 8 countries

United States18 sites

  • Quest Therapeutics of Avon Lake dba Haidar Almhana Nieding LLC

    Avon Lake, Ohio, 44012

  • 1st Allergy and Clinical Research Group, d/b/a IMUNOe Research Centers

    Centennial, Colorado, 80112

  • Medical University of South Carolina

    Charleston, South Carolina, 29425

  • Cincinnati Children's Hospital Medical Center

    Cincinnati, Ohio, 45229

  • Relaro Medical Trials, LLC

    Dallas, Texas, 75243

  • Eastside Therapeutic Resource, Inc. dba Core Clinical Research

    Everett, Washington, 98201

  • The EHS Medical Practice, PA, D/B/A Sarkis Clinical Trials

    Gainesville, Florida, 32607

  • Cortica Inc. (Glendale)

    Glendale, California, 91361

  • Red Oak Psychiatry Associates, PA

    Houston, Texas, 77090

  • Clinical Research of Southern Nevada, LLC

    Las Vegas, Nevada, 89128

  • AMR Baber Research Incorporated

    Naperville, Illinois, 60563

  • APG Research, LLC

    Orlando, Florida, 32803

  • The Children's Hospital of Philadelphia

    Philadelphia, Pennsylvania, 19146

  • Southwest Autism Research & Resource Center

    Phoenix, Arizona, 85006

  • AIM Trials, LLC

    Plano, Texas, 75093

  • Cortica Inc. (San Rafael)

    San Rafael, California, 94903

  • ERG Clinical Research - New York, PLLC DBA Richmond Behavioral Associates

    Staten Island, New York, 10314

  • Children's Research Institute

    Washington D.C., District of Columbia, 20010

Other trials in United States

Italy11 sites

  • Azienda Ospedaliero Universitaria (AOU) Consorziale Policlinico

    Bari, 70124

  • La Nostra Famiglia - Scientifica IRCCS Eugenio Medea

    Bosisio Parini, 23842

  • The Childhood and Adolescence Neuropsychiatry Clinic - University of Cagliari and Pediatric Hospital "A. Cao" - ASL 8 of Cagliari

    Cagliari, 09134

  • Policlinico Riuniti - Azienda Ospedaliero Universitaria

    Foggia, 71122

  • IRCCS Istituto Giannina Gaslini

    Genova, 16147

  • Azienda Ospedaliera Universitaria "Federico II"

    Naples, 80131

  • Fondazione Istituto Neurologico Nazionale Casimiro Mondino - IRCCS

    Pavia, 27100

  • Fondazione PTV - Policlinico Tor Vergata

    Roma, 00133

  • IRCCS Ospedale Pediatrico Bambino Gesù

    Rome, 00165

  • Azienda Ospedaliera-Universitaria Senese

    Siena, 53100

  • Azienda Ospedaliera Universitaria Integrata di Verona (AOUI)

    Verona, 37126

Other trials in Italy

Spain7 sites

  • Hospital General de Alicante

    Alicante, 03010

  • Institut Global d´Atenció Integral del Neurodesenvolupament (IGAIN)

    Barcelona, 08007

  • Hospital Universitari Vall d'Hebron

    Barcelona, 08035

  • Hospital Clínic de Barcelona

    Barcelona, 08036

  • Complejo Asistencial Universitario de Burgos

    Burgos, 09006

  • Hospital Universitario Infanta Leonor

    Madrid, 28031

  • Complejo Asistencial de Zamora

    Zamora, 49021

Other trials in Spain

Poland6 sites

  • Gdańskie Centrum Zdrowia Sp. z o.o.

    Gdansk, 80-542

  • Centrum Badań Klinicznych PI-House Sp. z o.o.

    Gdansk, 80-546

  • NAVICULA - Centrum Diagnozy i Terapii Autyzmu

    Lodz, 91-129

  • Ginemedica Sp. Zoo, S.K.

    Wroclaw, 50-414

  • Centrum Neuropsychiatrii NEUROMED SP ZOZ

    Wroclaw, 54-238

  • MedicMental Indywidualna Specjalistyczna Praktyka Lekarska Monika Szewczuk-Boguslawska

    Wroclaw, 54-617

Other trials in Poland

France4 sites

  • Centre Hospitalier Charles Perrens

    Bordeaux, 33076

  • Centre de Ressources Autisme Rhône-Alpes - Center Hospitalier le Vinatier

    Bron, 69678

  • CHU de Nantes

    Nantes, 44093

  • L'Assistance Publique - Hôpitaux de Paris, labélisé Institut Carnot

    Paris, 75019

Other trials in France

Hungary4 sites

  • Vadaskert Hospital

    Budapest, H-1021

  • Magyarországi Református Egyház Bethesda Gyermekkórháza

    Budapest, H-1146

  • Békés Megyei Központi Kórház

    Gyula, H-5700

  • Szegedi Tudományegyetem

    Szeged, H-6725

Other trials in Hungary

Serbia4 sites

  • Institute of Mental Health

    Belgrade, 11000

  • University Clinical Center Kragujevac, Clinic for Psychiatry

    Kragujevac, 34000

  • University Clinical Center Nis, Center for Mental Health

    Niš, 18000

  • Clinical Center of Vojvodina, Clinic for Psychiatry

    Novi Sad, 21000

Other trials in Serbia

Australia3 sites

  • Monash Health

    Clayton, Victoria, 3168

  • Murdoch Children's Research Institute

    Parkville, Victoria, 3052

  • Children's Health Queensland Hospital and Health Service

    South Brisbane, QDL, 4101

Other trials in Australia

About this study

Official title: A Phase 2, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Pimavanserin for the Treatment of Irritability Associated With Autism Spectrum Disorder

6-week, randomized, double-blind, fixed-dose, placebo-controlled, parallel group study in children and adolescents (aged 5 to17 years) with autism spectrum disorder (ASD) with irritability, agitation, or self-injurious behaviors to study the efficacy and safety of pimavanserin

Read the detailed description

This study will be conducted as a 6-week, randomized, double-blind, fixed-dose, placebo-controlled, parallel group study in children and adolescents (5 through 17 years of age) with ASD with irritability, agitation, or self-injurious behaviors.

Being tested
Pimavanserin, Placebo
Keywords
Randomized, Placebo-controlled

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PimavanserinDrug

    Also called Nuplazid

    Pimavanserin

  • PlaceboDrug

    Pimavanserin matching placebo

Study groups in NCT05523895
Study groupRoleWhat they receive
PlaceboPlacebo comparatorPlacebo given once daily, as one capsule matching in size and color the respective pimavanserin treatment
Receives: Drug: Placebo
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
Receives: Drug: Pimavanserin
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
Receives: Drug: Pimavanserin

What is being measured

The primary outcome is the main question the study is designed to answer.

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

    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.

    Measured: 6 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted31 Aug 2022
  2. Study start9 Aug 2022
  3. Primary completion27 Sep 2024
  4. Study completion27 Sep 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2/3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
237 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05523895
Sponsor's protocol ID
ACP-103-069
Status last verified
Aug 2025
First submitted
29 Aug 2022
Last updated
24 Aug 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Bugarski-Kirola D, Hofbauer RK, Sameljak S, Marco EJ, Sumila A, Darwish M, Ortiz S, Liu IY, Nunez R, Zhang PH, Arango C. Pimavanserin for Irritability in Children and Adolescents With Autism Spectrum Disorder: Phase 2 Randomized Trial. J Am Acad Child Adolesc Psychiatry. 2026 May 19:S0890-8567(26)00229-7. doi: 10.1016/j.jaac.2026.05.007. Online ahead of print.

    PubMed 42162607

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing Pimavanserin in people with Irritability Associated With Autism Spectrum Disorder, run by ACADIA Pharmaceuticals Inc. at 57 sites in 8 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 24 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 57 sites in United States, Italy, Spain, Poland, France and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 24 Aug 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change From Baseline at Week 6 in Caregiver-rated Aberrant Behavior Checklist Irritability (ABC-I) Subscale Score (time frame: 6 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05523895, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Aug 2025.

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