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Autism Spectrum DisorderPhase 2NCT05999240

Pimavanserin for Rigid-compulsive Symptoms in Autism Spectrum Disorder

A Phase 2 study testing Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID] in people with Autism Spectrum Disorder, run by New York State Psychiatric Institute at 2 sites in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

This Phase 2 study examines the safety, tolerability, and preliminary efficacy of pimavanserin in individuals with Autism Spectrum Disorder. Male or female participants aged 12 to 40 years of age will be randomized to receive single doses of either placebo or pimavanserin in this randomized, placebo-controlled… Read more about this study

Who is it for?
Ages 12 to 40 years
Conditions the study is for
Autism Spectrum Disorder
What is being tested?
Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID]
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
30 participants
Where
2 sitesUnited States
Study dates
1 Oct 2025to 31 Dec 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

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 12 to 40 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • Participant must be at least 12 years old and no greater than 40 years old.
  • Participants 18 years of age or older or a legally acceptable representative must be able and willing to sign an informed consent document indicating understanding of the protocol and procedures and willingness to participate in full. For a participant who is under 18 years of age, a parent or guardian must sign an informed consent document indicating understanding the protocol and procedures and willingness to participate in full. When appropriate to the participants developmental level and age, assent will be used to indicate understanding and willingness to participant. If the participant is unable to sign the assent form, the participant must provide verbal or non-verbal confirmation of willingness to continue with study procedures. Each site will abide by their respective institutional requirements regarding consent of adult informants. For adult participants at the New York site only, a parent, caregiver, or other adult informant must sign an informed consent document indicating understanding the requirements for completing their portion of the study and their willingness to participate, due to institutional human subjects requirements.
  • Participant must have a diagnosis of Autism Spectrum Disorder, according to DSM-5 criteria, made by a licensed study psychiatrist or psychologist and supported by the Autism Diagnostic Observation Schedule 2 (ADOS-2) completed at screening or within the past 12 months prior to screening by an appropriately trained professional.
  • Participant must have a Clinical Global Impression of Severity for Repetitive Behavior of 4 or greater, as rated by the study psychiatrist or psychologist at Screening and at Baseline
  • Participant must have a non-verbal IQ of greater than or equal to 70 as determined by the 4-subtest Wechsler Abbreviated Scale of Intelligence.
  • Participant must be able to speak and understand English in order to complete study measures.
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  • Participant must live with a parent, primary caregiver, or other adult informant who can complete study measures on the basis of spending an average of at least 4 hours per day with the participant
  • Parent, primary caregiver, or other adult informant must speak and understand English in order to complete study measures.
  • Participant must be able to self-administer study medication or have parent/caregiver be able to administer study medication.
  • Participant must be able to swallow study medication whole with liquid.
  • Participant or legally acceptable representative must be willing to continue current medication(s) and behavioral intervention(s) and to not add or change medication(s) or behavioral intervention(s) over the full course of the study.

Who cannot join

  • Participant is judged by the Investigator to be unable to perform or comply with all study specific requirements.
  • Participant is an employee of an investigator with direct involvement in the proposed study or other studies under the direction of a study investigator, or is a family member of an investigator.
  • Participant has a history of any severe or unstable psychiatric condition (e.g., schizophrenia or other psychotic disorder, bipolar disorder, major depressive disorder) that, in the opinion of the Investigator, could confound the interpretation of the study results or put the participant at undue risk. An acute episode of a mood disorder will be considered exclusionary; a participant with a history of mild to moderate mood disorder may be included in the study under the discretion of the Investigator. Other stable psychiatric conditions are permitted at the discretion of the Investigator (e.g., attention deficit hyperactivity disorder, generalized anxiety disorder, etc.).
  • Participant has a current or recent history of clinically significant suicidal ideation within the past 6 months, corresponding to a score of 3 or higher (active suicidal ideation with some intent to act, without specific plan) on the Columbia Suicide Severity Rating Scale (C-SSRS), or a history of suicidal behavior within the past year, as validated by the C-SSRS at screening or Day 1.
  • Participant has met DSM-5 criteria for a substance abuse disorder within the last 6 months prior to Screening, except for disorders related to caffeine or nicotine.
  • Participant has a positive test for an illicit drug or cannabis at Screening or Baseline. Participants who test positive for cannabis and who have a valid prescription may be rescreened if they agree to abstain from the cannabis for the length of their participation in the study. The repeat test must be negative for them to participate in the study.
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  • Participant is taking a serotonin reuptake inhibitor or antipsychotic medication.
  • Participant has had a change to psychotropic medications within the last 2 months
  • Participant has received electroconvulsive therapy (ECT) in the last 6 months.
  • Participant has received new-onset psychotherapy or has had a change in the intensity of psychotherapy within the 2 months prior to Screening.
  • Participant has known allergies, hypersensitivity, or intolerance to Pimavanserin or its excipients.
  • Participant has received an investigational drug or used an investigational medical device within 3 months before the planned start of study or is currently enrolled in an investigational study.
  • Participant has a body mass index (BMI) <17 or >40 at Screening.
  • Participant has a known history of long QT syndrome or family history of sudden death.
  • Participant has a history of myocardial infarction, unstable angina, acute coronary syndrome, or cerebrovascular accident (CVA) within the last 4 months. Has greater than NYHA Class 2 congestive heart failure or Class 2 angina pectoris, sustained ventricular tachycardia (VT), ventricular fibrillation, torsade de pointes, or syncope due to an arrhythmia.
  • Participant has a history of neuroleptic malignant syndrome/serotonin syndrome.
  • Participant has had a seizure within the past 12 months. Individuals with seizure disorders who are on stable seizure medications (i.e., without seizures in the past 12 months) are permitted at the discretion of the Investigator.
  • Participant is pregnant or breast-feeding, or planning to become pregnant or breastfeed while enrolled in this study or within 3 months after the last dose of study drug.
  • Participant has current evidence, or a history within the previous 3 months prior to screening, of a serious and/or unstable neurologic, cardiovascular, respiratory, gastrointestinal, renal, hepatic, hematologic, or other medical disorder, that, in the opinion of the Investigator, would jeopardize the safe participation of the Participant in the study.
  • Participant has a history of malignancy within 5 years before screening (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix, or malignancy that in the opinion of the Investigator, is considered cured with minimal risk of recurrence).
  • Participant has a known history of a positive hepatitis C virus (HCV) or human immunodeficiency virus (HIV) test.
  • Participant has a Screening or Baseline ECG with a QTcF>450ms when the QRS duration is <120 ms or has a Screening or Baseline ECG with a QTcF>470 ms when the QRS duration is >120 ms.
  • Participant has laboratory evidence of hypothyroidism at Screening, as measured by thyroid stimulating hormone (TSH) and reflex free thyroxine (T4). If TSH is abnormal and the reflex free T4 is normal, the Participant may be enrolled.
  • Participant has current unstable diabetes or glycosylated hemoglobin (HbAIc) >8% at Screening.
  • Participant has other clinically significant laboratory abnormalities that, in the opinion of the Investigator, would jeopardize the safe participation of the study Participant.

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Zahra Raza, BS contact

914-997-5532

zahra.raza@nyspi.columbia.edu

Suvekcha Bhattachan, MA contact

914-997-5587

suvekcha.bhattachan@nyspi.columbia.edu

United States2 sites, 2 recruiting

  • University of Kansas, Center for Research

    Lawrence, Kansas, 66045

    Anjali Pradeep, M.A, 785-864-4461, brainlab@ku.edu

    Matt Mosconi, PhD

    Recruiting

  • Center for Autism and the Developing Brain

    White Plains, New York, 10605

    Alyssa Verdes, B.A., 914-997-5532, alyssa.verdes@nyspi.columbia.edu

    Suvekcha Bhattachan, M.A., 914-997-5587, suvekcha.bhattachan@nyspi.columbia.edu

    Recruiting

Other trials in United States

About this study

Official title: A Target Engagement Study of Pimavanserin for Behavioral Inflexibility With Open Label Trial for Rigid Rigid-compulsive Behavior in Adolescents and Adults With Autism

This Phase 2 study examines the safety, tolerability, and preliminary efficacy of pimavanserin in individuals with Autism Spectrum Disorder. Male or female participants aged 12 to 40 years of age will be randomized to receive single doses of either placebo or pimavanserin in this randomized, placebo-controlled, cross-over designed study, followed by open label extension.

Read the detailed description

The goal of this clinical trial is to learn the safety, tolerability and to assess pimavanserin for effects on behavioral rigidity and rigid-compulsive behavior in adolescents and adults with Autism Spectrum Disorder.

Participants who meet protocol criteria will be randomly assigned to receive either pimavanserin or placebo in a 1:1 ratio in the Treatment Period. After completing the second experimental day of the cross-over trial, participants will immediately enter the Open-Label Trial, where they will take pimavanserin 34 mg for six weeks total. There will be 2 recruiting sites with a total sample of 30 participants. Blinding will be maintained by using identical tablets containing either Pimavanserin or placebo.

Being tested
Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID], Placebo
Keywords
Pimavanserin, Nuplazid, Antiparkinson Agents, Antipsychotic Agents, Serotonin 5-HT2 Receptor Antagonist, Physiological Effects of Drugs, Serotonin Agents, Autism Spectrum Disorder, Autistic Disorder
Medical subject headings
Autism Spectrum Disorder, Autistic Disorder

What participants receive

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

  • Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID]Drug

    Also called Nuzplazid

    Participants will be randomized to take a single dose of either pimavanserin 34 mg or placebo at Visit 2.

  • PlaceboDrug

    Placebo for Pimavanserin Tartrate 34 Mg ORAL CAPSILE [NUPLAZID]

Study groups in NCT05999240
Study groupRoleWhat they receive
Pimavanserin tartrateExperimentalPimavanserin 34 mg white to off-white capsules.
Receives: Drug: Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID]
PlaceboPlacebo comparatorPlacebo to Pimavanserin tartrate
Receives: Drug: Placebo

What is being measured

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

  1. Evaluate the impact of a single dose of pimavanserin 34 mg versus placebo

    Assessed using cognitive neuroscience task, comparison between pimavanserin and placebo within participants in single-dose cross-over experiment.

    Measured: Post Intervention, 30 days after study completion

  2. Evaluate pimavanserin for treatment of restricted/repetitive behavior in ASD

    Assessed using the Repetitive Behavior Scale - Revised (RBS-R) rated at baseline, 3, and 6 weeks. The RBS-R is a 44-item self-report form used to measure the wide range of repetitive behavior in children, adolescents, and adults with Autism Spectrum disorders. The scale consists of six subscales with questions related to Stereotyped Behavior, Self-injurious Behavior, Compulsive Behavior, Routine Behavior, Sameness Behavior, and Restricted Behavior rated between 0 to 3 on severity of each item.

    Measured: 6 weeks of Open-Label treatment

Secondary outcomes (1)

  1. Explore the effects of pimavanserin on an electroencephalogram event-related potential (EEG/ERP) reversal learning test

    Explore the effects of pimavanserin on an electroencephalogram event-related potential (EEG/ERP) learning task in the cross-over comparison (visits 2 and 3) and again at the end of 6 weeks of open label treatment.

    Measured: Post 6-week treatment

Timeline

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

  1. First posted21 Aug 2023
  2. Study start1 Oct 2025
  3. Primary completion31 Oct 2027 (estimated)
  4. Study completion31 Dec 2027 (estimated)

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
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Model description
This study plans to enroll 30 participants between the ages of 12-40 years old with a diagnosis of autism spectrum disorder to participate in a randomized, placebo-controlled, cross-over designed study. Participants will be randomized to take a single dose of either pimavanserin 34 mg or placebo (Visit 2) three hours before beginning a cognitive neuroscience battery. One week later (Visit 3), participants will take the other medication (placebo or pimavanserin 34 mg) three hours before beginning the cognitive neuroscience battery. After completing the second experimental day, participants will immediately enter the Open Label Trial, where they will take pimavanserin 34 mg for six weeks total, with study visits at 3 weeks (Visit 4) and 6 weeks (Visit 5) to complete safety and primary/secondary outcome measures, followed by a follow-up phone call within 30 days after completing the open label trial.
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05999240
Sponsor's protocol ID
8449
Status last verified
Aug 2026
First submitted
13 Aug 2023
Last updated
2 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID] in people with Autism Spectrum Disorder, run by New York State Psychiatric Institute at 2 sites in United States.

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 25 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: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in United States. 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 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.

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

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

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

Contact Zahra Raza, BS (914-997-5532, zahra.raza@nyspi.columbia.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Evaluate the impact of a single dose of pimavanserin 34 mg versus placebo (time frame: Post Intervention, 30 days after study completion). The study lists 2 primary outcomes in all. 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 NCT05999240.

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 2 Sep 2026.

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