Irritability Associated With Autism Spectrum DisorderPhase 2/3NCT05555615
Extension Study of Pimavanserin in 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 48 sites in 8 countries.
Trial summary
52-week, open-label extension study of double-blind study ACP-103-069 to determine the long-term safety and tolerability of pimavanserin for the treatment of irritability associated with ASD in children and adolescents (aged 5 to 17 years). Read more about this study
- Who is it for?
- Ages 5 to 18 years
- Conditions the study is for
- Irritability Associated With Autism Spectrum Disorder
- What is being tested?
- Pimavanserin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 209 participants
- Where
- 48 sitesin 8 countries
- Study dates
- 2 Nov 2022to 14 Feb 2025
- 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 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Has completed the treatment period of study ACP-103-069
- Informed consent prior to the conduct of any study procedures
- Continues to be both clinically stable and not at imminent risk of suicide or injury to self, others, or property
- Continues to be medically stable at enrollment
- 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
- Patient or parent/legally accepted representative is judged by the Investigator to be inappropriate for the study
- 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
- 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
- Serious and/or unstable psychiatric, neurologic, cardiovascular, respiratory, gastrointestinal, renal, hepatic, hematologic, or other medical disorder, including cancer or malignancies
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- Any change in medical or treatment status that may increase the risk associated with taking pimavanserin, would interfere with safety assessments, or would confound the interpretation of study results
- Clinically significant abnormal ECG of protocol-defined cardiac conduction abnormalities
- Weight <15 kg
- 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
48 sites in 8 countries.
48 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, 32803-3809
The Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19146
Southwest Autism Research and Resource Center
Phoenix, Arizona, 85006
AIM Trials, LLC
Plano, Texas, 75093
Cortica Inc.
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
Italy6 sites
La Nostra Famiglia - Scientifica IRCCS Eugenio Medea
Bosisio Parini, LC, 23842
Policlinico Riuniti - Azienda Ospedaliero Universitaria
Foggia, 71122
Azienda Ospedaliera Universitaria "Federico II"
Naples, 80131
Fondazione Istituto Neurologico Nazionale Casimiro Mondino - IRCCS
Pavia, 27100
Fondazione PTV - Policlinico Tor Vergata
Rome, 00133
Azienda Ospedaliera Universitaria Integrata di Verona (AOUI)
Verona, 37126
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
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
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
Spain4 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
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, Queensland, 4101
Hungary3 sites
Magyarországi Református Egyház Bethesda Gyermekkórháza
Budapest, H-1146
Békés Megyei Központi Kórház
Gyula, H-5700
Szegedi Tudományegyetem
Szeged, H-6725
About this study
Official title: A 52-Week Open-Label Extension Study of Pimavanserin in Children and Adolescents With Irritability Associated With Autism Spectrum Disorder (ASD)
52-week, open-label extension study of double-blind study ACP-103-069 to determine the long-term safety and tolerability of pimavanserin for the treatment of irritability associated with ASD in children and adolescents (aged 5 to 17 years).
ACP-103-069 is a 6-week, randomized, double-blind, fixed-dose, placebo controlled, parallel group study of pimavanserin in children and adolescents with irritability associated with autism spectrum disorder (ASD).
Read the detailed description
This study will be conducted as a 52-week, open-label extension study of the antecedent double-blind study to determine the long-term safety and tolerability of pimavanserin for the treatment of irritability associated with ASD in children and adolescents (5 through 17 years old at the time of enrolling into the antecedent double-blind study).
- Being tested
- Pimavanserin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PimavanserinDrug
Also called Nuplazid
Pimavanserin given once daily, as capsule of 10, 20, or 34 mg dose strength, respectively, according to the patient's age
| Study group | Role | What they receive |
|---|---|---|
| Pimavanserin | Experimental | Pimavanserin once daily. All patients will receive the pimavanserin low dose (patients aged 5 to 12 years: 10 mg/day pimavanserin; patients aged 13 to 17 years: 20 mg/day) the first 2 weeks of the study. Thereafter, the dose may be increased to the high dose (5 to 12 years: 20 mg/day; 13 to 17 years: 34 mg/day) based on the Investigator's assessment of clinical response.
After Week 2 and up to Week 20, dose adjustments are allowed at any clinic visit based on the Investigator's assessment of clinical response and tolerability. No further dose adjustments are allowed after Week 20. Receives: Drug: Pimavanserin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Treatment-emergent Adverse Events
Number (%) of patients with treatment emergent adverse events
Measured: 52 weeks
Secondary outcomes (1)
Aberrant Behavior Checklist-Irritability (ABC-I) and Clinical Global Impression-Improvement (CGI-I) Response Rate
The response rate was defined as the proportion of patients with at least 25% reduction from baseline to Week 52 in ABC-I and a CGI-I of irritability score of 1 (very much improved) or 2 (much improved) at Week 52, compared to baseline.
Baseline was the baseline of the antecedent double-blind study APC-103-069. The ABC is a parent/caregiver-rated scale comprised of 5 subscales encompassing 58 items. Subscales are irritability, lethargy, stereotypic behavior, hyperactivity, and inappropriate speech. Items are rated on a 4-point Likert scale ranging from 0 (not at all a problem) to 3 (the problem is severe), with higher scores indicating more severe problems. Subscale scores are calculated by summing the items within that subscale.
The CGI-I is a clinician-rated, 7-point scale to assess how much the patient's illness (here: the patient's irritability) has changed relative to baseline. Scores range from 1 (very much improved) to 7 (very much worse).
Measured: 52 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Sep 2022
- Study start2 Nov 2022
- Primary completion14 Feb 2025
- Study completion14 Feb 2025
Why it stopped: The study was terminated for business reasons and not due to safety concerns.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Irritability Associated With Autism Spectrum DisorderStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 209 participants (actual)
Sponsor and investigators
- Lead sponsor
- ACADIA Pharmaceuticals Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05555615
- Sponsor's protocol ID
- ACP-103-070
- Status last verified
- Nov 2025
- First submitted
- 30 Aug 2022
- Last updated
- 3 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A 52-Week Open-Label Extension Study of Pimavanserin in Children and Adolescents With Irritability Associated With Autism Spectrum Disorder (ASD)
- ClinicalTrials.gov ID
- NCT05555615
- Acronym / sponsor ID
- ACP-103-070
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The study was terminated for business reasons and not due to safety concerns.
- Enrolment
- 209 participants (actual)
- Lead sponsor
- ACADIA Pharmaceuticals Inc.Industry (pharma, biotech, devices)
- Study start
- 2 Nov 2022 (actual)
- Primary completion
- 14 Feb 2025 (actual)
- Study completion
- 14 Feb 2025 (actual)
- First posted
- 27 Sep 2022 (actual)
- Results
- Posted 3 Dec 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
52-week, open-label extension study of double-blind study ACP-103-069 to determine the long-term safety and tolerability of pimavanserin for the treatment of irritability associated with ASD in children and adolescents (aged 5 to 17 years).
ACP-103-069 is a 6-week, randomized, double-blind, fixed-dose, placebo controlled, parallel group study of pimavanserin in children and adolescents with irritability associated with autism spectrum disorder (ASD).
Detailed description
This study will be conducted as a 52-week, open-label extension study of the antecedent double-blind study to determine the long-term safety and tolerability of pimavanserin for the treatment of irritability associated with ASD in children and adolescents (5 through 17 years old at the time of enrolling into the antecedent double-blind study).
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Pimavanserin | Experimental | Drug: PimavanserinPimavanserin once daily. All patients will receive the pimavanserin low dose (patients aged 5 to 12 years: 10 mg/day pimavanserin; patients aged 13 to 17 years: 20 mg/day) the first 2 weeks of the study. Thereafter, the dose may be increased to the high dose (5 to 12 years: 20 mg/day; 13 to 17 years: 34 mg/day) based on the Investigator's assessment of clinical response. After Week 2 and up to Week 20, dose adjustments are allowed at any clinic visit based on the Investigator's assessment of clinical response and tolerability. No further dose adjustments are allowed after Week 20. |
Who may qualify
- Ages
- 5 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- Has completed the treatment period of study ACP-103-069
- Informed consent prior to the conduct of any study procedures
- Continues to be both clinically stable and not at imminent risk of suicide or injury to self, others, or property
- Continues to be medically stable at enrollment
- 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
Key exclusion criteria (10 listed)
- Patient or parent/legally accepted representative is judged by the Investigator to be inappropriate for the study
- 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
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PimavanserinAlso: NuplazidPimavanserin given once daily, as capsule of 10, 20, or 34 mg dose strength, respectively, according to the patient's age | Drug | Pimavanserin |
Primary outcome
Treatment-emergent Adverse Events
Time frame: 52 weeks
Number (%) of patients with treatment emergent adverse events
1 secondary outcome
Aberrant Behavior Checklist-Irritability (ABC-I) and Clinical Global Impression-Improvement (CGI-I) Response Rate
Time frame: 52 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
48 sites in 8 countries: see every site and its status.
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 48 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 5 inclusion and 10 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: stopped early, as of the sponsor's last update on 3 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 48 sites in United States, Italy, Poland, France, Serbia 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. 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 3 Dec 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?
Treatment-emergent Adverse Events (time frame: 52 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 3 Dec 2025.