Neurodegenerative DiseasesPhase 4NCT05357612
Characterization of the Serotonin 2A Receptor Selective PET Tracer [18F]MH.MZ in Patients With Neurodegenerative Diseases
A Phase 4 study testing Pimavanserin in people with Neurodegenerative Diseases and Parkinson Disease, run by Vanderbilt University Medical Center at 1 site in United States.
Trial summary
It is hypothesize that patients with clinically diagnosed neurodegenerative diseases will have significantly different receptor occupancy of 5HT2A receptors compared to a healthy age/sex-matched control group. Read more about this study
- Who is it for?
- Ages 50 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Neurodegenerative Diseases, Parkinson Disease, Parkinson Disease Psychosis
- What is being tested?
- Pimavanserin
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 1 siteUnited States
- Study dates
- 23 Jan 2023to Aug 2027
- Phase
- Phase 4
- 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 50 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patient arm - clinical diagnosis of Parkinson disease, diffuse Lewy body disease, multiple systems atrophy, Huntington's Disease, Frontotemporal Dementia, and other variants
- Healthy arm - age and gender matched to patient arm
- Psychosis (presence of hallucinations or delusions) starting after the diagnosis of Parkinson's disease, occurring at least weekly for 4 weeks, severe enough to warrant treatment.
- Study partner available for study visits
Who cannot join
- Prior stroke or other uncontrolled serious neurological or medical illness
- Contra-indication or inability to tolerate MRI scan
- Use of serotonergic medications in the last 6 weeks
- Incapable of providing independent consent.
- Pregnant or breastfeeding women
- psychosis due to a metabolic, toxic, or primary psychiatric disease
Show all 9Show fewer
- Deemed unable to complete neurocognitive testing
- For PD Participants: current or prior use of pimavanserin
- Use of antipsychotics in the last 2 weeks
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Katie Hay, MS contact
United States1 site, 1 recruiting
- Recruiting
Vanderbilt University Medical Center
Nashville, Tennessee, 37212
Levi Pettit, BA, 615-421-0569, levi.f.pettit@vumc.org
Katie Hay, MS, 6158757403, katie.orourke@vumc.org
About this study
It is hypothesize that patients with clinically diagnosed neurodegenerative diseases will have significantly different receptor occupancy of 5HT2A receptors compared to a healthy age/sex-matched control group. This will be tested by measuring 5HT2A receptor density using the PET radioligand (R)-[18F]MH.MZ in both populations.
Read the detailed description
It is hypothesized that improvement in psychosis symptoms in patients taking pimavanserin will be associated with increased baseline receptor density (Hypothesis 1A), and increased receptor occupancy of 5HT2A receptors following pimavanserin administration (Hypothesis 1B). This will be done by measuring 5HT2A receptor density using the PET radioligand (R)-[18F]MH.MZ within predefined symptom networks for hallucinations, delusions, and sleep. A PET scan will be obtained in PD patients with psychosis at enrollment to measure baseline 5HT2A receptor density and then again after 6 weeks of pimavanserin. The change in binding between baseline and post-drug treatment window will be used to measure 5HT2A receptor occupancy.
It is hypothesize that improvement in psychosis symptoms in patients taking pimavanserin will be associated with increased functional connectivity and cerebral blood flow within predefined symptom networks for hallucinations, delusions, and sleep. This will be tested by obtaining MRI scans assessing resting state functional connectivity and arterial spin labeling in PD patients with psychosis at enrollment (baseline) and then again after 6 weeks of pimavanserin.
It is hypothesized that functional neuroimaging changes in response to pimavanserin will be associated with baseline 5HT2A receptor density and 5HT2A receptor occupancy after pimavanserin administration. To test this hypothesis, the differences in functional neuroimaging measures and PET 5HT2A receptor will be measured in PD psychosis patients off (at baseline) and on Pimavanserin (post-treatment window).
- Being tested
- Pimavanserin
- Medical subject headings
- Neurodegenerative Diseases, Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PimavanserinDrug
PD related Psychosis
| Study group | Role | What they receive |
|---|---|---|
| Pimavanserin | Experimental | Not described Receives: Drug: Pimavanserin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in 5HT2A receptor density measured using the PET radioligand MH.MZ
Receptor density (Bmax) of 5HT2A receptors measured using the PET radioligand MH.MZ uptake in regions of interest.
Measured: Baseline and 6 weeks after intervention of Pimavanserin
Change in 5HT2A receptor binding occupancy measured using the PET radioligand MH.MZ
Receptor binding occupancy (RO) of 5HT2A receptors measured using the PET radioligand MH.MZ uptake in regions of interest.
Measured: Baseline and 6 weeks after intervention of Pimavanserin
Secondary outcomes (3)
Change in psychosis severity
Change in psychosis severity 6 weeks after starting pimavanserin, as measured by Clinician-Rated Dimensions of Psychosis Symptom Severity (CRD-PSS)18; Domain I (Delusions). Low scores indicate better outcome.
Measured: Baseline and 6 weeks after intervention of Pimavanserin
Change in psychosis severity
Change in psychosis severity 6 weeks after starting pimavanserin, as measured by Clinician-Rated Dimensions of Psychosis Symptom Severity (CRD-PSS)18; Domain II (Hallucinations). Low scores indicate better outcome.
Measured: Baseline and 6 weeks after intervention of Pimavanserin
Changes to functional connectivity and ASL bloodflow
Changes to functional connectivity and ASL bloodflow (mL/g/min) within pre-defined networks for delusions, hallucinations, and sleep after 6 weeks of Pimavanserin.
Measured: Baseline and 6 weeks after intervention of Pimavanserin
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 May 2022
- Study start23 Jan 2023
- Primary completionJun 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Neurodegenerative DiseasesStudies of the same condition, open and under way.
- More trials run by Vanderbilt University Medical CenterThe sponsor's other registered studies.
- 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 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- ACADIA Pharmaceuticals Inc.
- Responsible party
- Principal investigator, Richard Darby, Vanderbilt University Medical Center
- Investigators
- Ciaran Considine, PhD, Principal investigator, Vanderbilt University Medical CenterRichard Darby, MD, Principal investigator, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05357612
- Sponsor's protocol ID
- 212028
- Status last verified
- Aug 2025
- First submitted
- 20 Apr 2022
- Last updated
- 7 Aug 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of the Serotonin 2A Receptor Selective PET Tracer [18F]MH.MZ in Patients With Neurodegenerative Diseases
- ClinicalTrials.gov ID
- NCT05357612
- Acronym / sponsor ID
- 212028
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Collaborators
- ACADIA Pharmaceuticals Inc.
- Study start
- 23 Jan 2023 (actual)
- Primary completion
- Jun 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 3 May 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
It is hypothesize that patients with clinically diagnosed neurodegenerative diseases will have significantly different receptor occupancy of 5HT2A receptors compared to a healthy age/sex-matched control group. This will be tested by measuring 5HT2A receptor density using the PET radioligand (R)-[18F]MH.MZ in both populations.
Detailed description
It is hypothesized that improvement in psychosis symptoms in patients taking pimavanserin will be associated with increased baseline receptor density (Hypothesis 1A), and increased receptor occupancy of 5HT2A receptors following pimavanserin administration (Hypothesis 1B). This will be done by measuring 5HT2A receptor density using the PET radioligand (R)-[18F]MH.MZ within predefined symptom networks for hallucinations, delusions, and sleep. A PET scan will be obtained in PD patients with psychosis at enrollment to measure baseline 5HT2A receptor density and then again after 6 weeks of pimavanserin. The change in binding between baseline and post-drug treatment window will be used to measure 5HT2A receptor occupancy.
It is hypothesize that improvement in psychosis symptoms in patients taking pimavanserin will be associated with increased functional connectivity and cerebral blood flow within predefined symptom networks for hallucinations, delusions, and sleep. This will be tested by obtaining MRI scans assessing resting state functional connectivity and arterial spin labeling in PD patients with psychosis at enrollment (baseline) and then again after 6 weeks of pimavanserin.
It is hypothesized that functional neuroimaging changes in response to pimavanserin will be associated with baseline 5HT2A receptor density and 5HT2A receptor occupancy after pimavanserin administration. To test this hypothesis, the differences in functional neuroimaging measures and PET 5HT2A receptor will be measured in PD psychosis patients off (at baseline) and on Pimavanserin (post-treatment window).
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Pimavanserin | Experimental | Drug: Pimavanserin |
Who may qualify
- Ages
- 50 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patient arm - clinical diagnosis of Parkinson disease, diffuse Lewy body disease, multiple systems atrophy, Huntington's Disease, Frontotemporal Dementia, and other variants
- Healthy arm - age and gender matched to patient arm
- Psychosis (presence of hallucinations or delusions) starting after the diagnosis of Parkinson's disease, occurring at least weekly for 4 weeks, severe enough to warrant treatment.
- Study partner available for study visits
Key exclusion criteria (9 listed)
- Prior stroke or other uncontrolled serious neurological or medical illness
- Contra-indication or inability to tolerate MRI scan
- Use of serotonergic medications in the last 6 weeks
- Incapable of providing independent consent.
- Pregnant or breastfeeding women
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 |
|---|---|---|
| PimavanserinPD related Psychosis | Drug | Pimavanserin |
Primary outcome
Change in 5HT2A receptor density measured using the PET radioligand MH.MZ
Time frame: Baseline and 6 weeks after intervention of Pimavanserin
Receptor density (Bmax) of 5HT2A receptors measured using the PET radioligand MH.MZ uptake in regions of interest.
Change in 5HT2A receptor binding occupancy measured using the PET radioligand MH.MZ
Time frame: Baseline and 6 weeks after intervention of Pimavanserin
Receptor binding occupancy (RO) of 5HT2A receptors measured using the PET radioligand MH.MZ uptake in regions of interest.
3 secondary outcomes
Change in psychosis severity
Time frame: Baseline and 6 weeks after intervention of Pimavanserin
Change in psychosis severity
Time frame: Baseline and 6 weeks after intervention of Pimavanserin
Changes to functional connectivity and ASL bloodflow
Time frame: Baseline and 6 weeks after intervention of Pimavanserin
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2026.
- Individual participant dataSharing planned: Undecided
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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.
Katie Hay, MS contact
Ciaran Considine, PhD principal investigator
Vanderbilt University Medical Center
Richard Darby, MD principal investigator
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Pimavanserin in people with Neurodegenerative Diseases and Parkinson Disease, run by Vanderbilt University Medical Center at 1 site 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 4 inclusion and 9 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 7 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
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 Levi Pettit, BA (6154210569, levi.f.pettit@vumc.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in 5HT2A receptor density measured using the PET radioligand MH.MZ (time frame: Baseline and 6 weeks after intervention of Pimavanserin). 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?
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 7 Aug 2026.