Pimavanserin for Rigid-Compulsive Symptoms in Autism Spectrum Disorder
This study is testing a medication called pimavanserin (NUPLAZID) to see if it can help with rigid-compulsive behaviors in people with Autism Spectrum Disorder. Researchers want to learn if pimavanserin is safe, how well people tolerate it, and if it can reduce these behaviors. You might be able to join if you are between 12 and 40 years old and have Autism Spectrum Disorder. The study will look at the effects of a single dose of pimavanserin compared to a placebo (an inactive substance), and then participants will take pimavanserin for six weeks. Success would mean pimavanserin helps reduce these behaviors. The current status of this study is unclear, and it plans to enroll 30 participants.
- Study design
- This is a randomized, placebo-controlled, cross-over study, meaning you would randomly receive either pimavanserin or a placebo, then switch. After this, you would take pimavanserin for six weeks in an open-label part of the study. A total of 30 participants are planned.
- What's involved
- You would take a single dose of either pimavanserin or placebo at Visit 2, and then take pimavanserin for six weeks during an open-label extension.
- Compensation
- Not stated in the trial record.
- Follow-up
- The study will evaluate the impact of pimavanserin 30 days after study completion and assess treatment effects at 6 weeks of open-label treatment.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
NCT05999240
Pimavanserin for Rigid-compulsive Symptoms in Autism Spectrum Disorder
Recruiting
PHASE2Ages 12–40InterventionalTreatmentNew York State Psychiatric InstituteInvestigator-initiated
~30 participants
Updated 2026-09-02 on ClinicalTrials.gov
What's tested:Pimavanserin Tartrate 34 Mg ORAL CAPSULE [NUPLAZID]Placebo
At a glance
Recruiting sites
2 of 2 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Evaluate the impact of a single dose of pimavanserin 34 mg versus placebo
Measured over Post Intervention, 30 days after study completion
+1 more outcome measured
Conditions
NCT05999240
Where you'd take part
This study runs at 2 sites. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.
Center for Autism and the Developing Brain
White Plains, New Yorkstudy coordinator listed
Recruiting
University of Kansas, Center for Research
Lawrence, Kansasstudy coordinator listed
Recruiting
Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.
Study leadership
- Jeremy Veenstra-VanderWeele, MD · PRINCIPAL_INVESTIGATOR · New York State Psychiatric Institute
- Matthew Mosconi, PhD · PRINCIPAL_INVESTIGATOR · University of Kansas Center for Autism Research and Training
Who to contact
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Eligibility criteria
Inclusion
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.
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.
Exclusion
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.
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.
What this trial measures
- Evaluate the impact of a single dose of pimavanserin 34 mg versus placeboPost Intervention, 30 days after study completion
Assessed using cognitive neuroscience task, comparison between pimavanserin and placebo within participants in single-dose cross-over experiment.
- Evaluate pimavanserin for treatment of restricted/repetitive behavior in ASD6 weeks of Open-Label treatment
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.