What side effects are associated with this type of intervention?

Common treatments for Parkinson's Disease include levodopa, dopamine agonists, cholinesterase inhibitors, and MAO B inhibitors. Levodopa, often combined with carbidopa, can cause nausea, dizziness, headache, and dyskinesias. Dopamine agonists may lead to side effects such as orthostatic hypotension, confusion, and hallucinations. Cholinesterase inhibitors, used for cognitive impairment, can worsen tremors and cause nausea. MAO B inhibitors are generally well-tolerated but can cause mild side effects like insomnia and headache. While the specific trial of (R)-[18F]MH.MZ focuses on imaging 5HT2A receptors, treatments affecting serotonin receptors, such as 5-HT1A agonists, have been studied for their potential to reduce levodopa-induced dyskinesias.

What prior FDA approvals exist?

The FDA has approved several drugs for the treatment of Parkinson's Disease, primarily focusing on dopaminergic therapies. These include levodopa (often combined with carbidopa), dopamine agonists like pramipexole and ropinirole, and MAO-B inhibitors such as selegiline and rasagiline. While (R)-[18F]MH.MZ is used for imaging and quantification of 5HT2A receptors, treatments directly targeting serotonin receptors in Parkinson's Disease are less common. However, drugs like sarizotan, a 5-HT1A agonist, have been studied for their potential to reduce levodopa-induced dyskinesias. Overall, the mainstay of treatment remains dopaminergic therapies, with ongoing research into other receptor targets.

What other types of research exist?

Promising novel alternatives to (R)-[18F]MH.MZ for Parkinson's Disease patients include [11C]dihydrotetrabenazine ([11C]DTBZ) for imaging the vesicular monoamine transporter system (VMAT2) and [18F]PI-2620 for assessing tau pathology. Both have shown potential in neurodegenerative disease contexts and could be considered for further evaluation in Parkinson's Disease treatment.

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Pimavanserin PET Tracer for Neurodegenerative Disease

Phase 4

Recruiting

Led By Richard Darby, MD

Research Sponsored by Vanderbilt University Medical Center

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Patient arm - clinical diagnosis of Parkinson disease, diffuse Lewy body disease, multiple systems atrophy, Huntington's Disease, Frontotemporal Dementia, and other variants

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

Must not have

For PD Participants: current or prior use of pimavanserin

Deemed unable to complete neurocognitive testing

Timeline

Screening 3 weeks

Treatment Varies

Follow Up baseline and 6 weeks after intervention of pimavanserin

Awards & highlights

Pivotal Trial

Drug Has Already Been Approved

No Placebo-Only Group

Summary

This trial tests if pimavanserin can help improve psychosis symptoms in Parkinson's Disease patients by affecting specific brain receptors. Pimavanserin is an atypical antipsychotic approved for treating hallucinations and delusions in Parkinson's disease psychosis. The study uses brain scans to measure changes over time.

Who is the study for?

This trial is for people with neurodegenerative diseases like Parkinson's, Lewy body disease, and others who experience psychosis. Participants need a study partner and must not have had strokes or serious illnesses that could interfere with the study. Pregnant women and those on certain medications recently are excluded.

What is being tested?

The trial is testing how a PET tracer called [18F]MH.MZ binds to serotonin receptors in patients compared to healthy controls. It aims to show differences in receptor occupancy between these groups using this imaging technique.

What are the potential side effects?

While specific side effects aren't listed for the PET tracer itself, potential risks may include discomfort from the injection of the tracer, allergic reactions, or anxiety during the MRI scan required by the protocol.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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I have been diagnosed with a neurodegenerative disease like Parkinson's or Huntington's.

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I have had severe hallucinations or delusions weekly for a month after being diagnosed with Parkinson's.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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I have Parkinson's and have taken or am taking pimavanserin.

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I am unable to complete tests for brain function.

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I have not had a stroke or any serious uncontrolled illness.

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I am unable to give consent on my own.

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I have psychosis not caused by substance abuse or a primary mental health condition.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ baseline and 6 weeks after intervention of pimavanserin

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~baseline and 6 weeks after intervention of pimavanserin

This trial's timeline: 3 weeks for screening, Varies for treatment, and baseline and 6 weeks after intervention of pimavanserin for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Change in 5HT2A receptor binding occupancy measured using the PET radioligand MH.MZ

Change in 5HT2A receptor density measured using the PET radioligand MH.MZ

Secondary study objectives

Change in psychosis severity

Changes to functional connectivity and ASL bloodflow

Side effects data

From 2021 Phase 4 trial • 6 Patients • NCT04188392

33%

sleepiness

17%

diarrhea

17%

headache

17%

weight gain

17%

skin irritation

17%

arthralgia

17%

dry mouth

100%

80%

60%

40%

20%

Study treatment Arm

Open-label Treatment

Awards & Highlights

Pivotal Trial

The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

Drug Has Already Been Approved

The FDA has already approved this drug, and is just seeking more data.

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

Trial Design

1Treatment groups

Experimental Treatment

Group I: PimavanserinExperimental Treatment1 Intervention

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

Pimavanserin

2018

Completed Phase 4

~3250

0 / 7Eligibility criteria met

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

Common treatments for Parkinson's Disease (PD) include levodopa, dopamine agonists, and MAO-B inhibitors. Levodopa replenishes dopamine levels, directly addressing the dopamine deficiency in PD. Dopamine agonists mimic dopamine by stimulating its receptors, helping manage symptoms and potentially slowing disease progression. MAO-B inhibitors increase dopamine availability by preventing its breakdown. Amantadine and anticholinergics are also used to manage symptoms. The PET tracer (R)-[18F]MH.MZ, which binds to 5HT2A receptors, is used for imaging and quantification of these receptors, which may be altered in PD. Understanding these mechanisms is crucial for tailoring treatments to manage symptoms effectively and potentially slow disease progression.

Dopamine agonists in Parkinson's disease.Efficacy and safety of 5-Hydroxytryptophan on levodopa-induced motor complications in Parkinson's disease: A preliminary finding.Pharmacologic approaches to the treatment of Huntington's disease.