Autonomic FailurePhase 1NCT04246437
[18F]F-DOPA Imaging in Patients With Autonomic Failure
A Phase 1 study testing [18F]FDOPA, Carbidopa 200mg oral dose and Entacapone 400mg oral dose in people with Autonomic Failure and Pure Autonomic Failure, run by Daniel Claassen at 1 site in United States.
Trial summary
Alpha-synucleinopathies refer to age-related neurodegenerative and dementing disorders, characterized by the accumulation of alpha-synuclein in neurons and/or glia. The anatomical location of alpha-synuclein inclusions (Lewy Bodies) and the pattern of progressive neuronal death (e.g. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Autonomic Failure, Pure Autonomic Failure, Parkinson Disease
- What is being tested?
- [18F]FDOPA, Carbidopa 200mg oral dose and Entacapone 400mg oral dose
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Feb 2020to 1 Feb 2027
- Phase
- Phase 1
- 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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patients with a diagnosis if pure autonomic failure
- Patients with autonomic failure and possible PD, MSA, or DLB
- Healthy adults aged 18 and above
- Clinical exam confirming clinical designation
Who cannot join
- Subjects who have any type of bioimplant activated by mechanical, electronic, or magnetic means (e.g., cochlear implants, pacemakers, neurostimulators, biostimulators, electronic infusion pumps, etc.), because such devices may be displaced or malfunction.
- Subjects who have any type of ferromagnetic bioimplant that could potentially be displaced.
- Subjects who have cerebral aneurysm clips.
- Subjects who may have shrapnel imbedded in their bodies (such as from war wounds), metal workers and machinists (potential for metallic fragments in or near the eyes).
- Subjects who are pregnant, because the effects of high field MRI on fetuses are not yet known.
- Minors (younger than 18 years)
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- Also excluded are subjects incapable of giving informed written consent:
- Subjects who cannot adhere to the experimental protocols for any reason, or have an inability to communicate with the researcher.
- Subjects who have limited mental ability to give informed consent, mentally retarded, altered mental status, mental disability, confusion, or psychiatric disorders.
- Prisoners
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Kaitlyn O'Rourke, MS contact
United States1 site, 1 recruiting
- Recruiting
Vanderbilt University Medical Center
Nashville, Tennessee, 37212
About this study
Alpha-synucleinopathies refer to age-related neurodegenerative and dementing disorders, characterized by the accumulation of alpha-synuclein in neurons and/or glia. The anatomical location of alpha-synuclein inclusions (Lewy Bodies) and the pattern of progressive neuronal death (e.g. caudal to rostral brainstem) give rise to distinct neurological phenotypes, including Parkinson's disease (PD), Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB). Common to these disorders are the involvement of the central and peripheral autonomic nervous system, where Pure Autonomic Failure (PAF) is thought (a) to be restricted to the peripheral autonomic system, and (b) a clinical risk factor for the development of a central synucleinopathy, and (c) an ideal model to assess biomarkers that predict phenoconversion to PD, MSA, or DLB. Such biomarkers would aid in clinical trial inclusion criteria to ensure assessments of disease- modifying strategies to, delay, or halt, the neurodegenerative process. One of these biomarkers may be related to the neurotransmitter dopamine (DA) and related changes in the substantia nigra (SN) and brainstem. [18F]F-DOPA is a radiolabeled substrate for aromatic amino acid decarboxylase (AAADC), an enzyme involved in the production of dopamine. Use of this radiolabeled substrate in positron emission tomography (PET) may provide insight to changes in monoamine production and how they relate to specific phenoconversions in PAF patients. Overall, this study aims to identify changes in dopamine production in key regions including the SN, locus coeruleus, and brainstem to distinguish between patients with PD, MSA, and DLB, which may provide vital information to predict conversion from peripheral to central nervous system disease.
- Conditions
- Autonomic Failure, Pure Autonomic Failure, Parkinson Disease, Multiple System Atrophy, Dementia With Lewy Bodies
- Being tested
- [18F]FDOPA, Carbidopa 200mg oral dose, Entacapone 400mg oral dose
- Keywords
- FDOPA, PET
- Medical subject headings
- Pure Autonomic Failure, Parkinson Disease, Multiple System Atrophy, Lewy Body Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[18F]FDOPADrug
Patients will receive a 3-D emission scan following a 6-8 mCi slow bolus injection of [18F]FDOPA over a 30 second period. Serial scans are started simultaneously with the bolus injection of radiotracer and are obtained for approximately 95 minutes.
Carbidopa 200mg oral doseDrug
Also called Lodosyn
30 minutes prior to the PET scan, patients will receive the 200mg oral dose of carbidopa to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging.
Entacapone 400mg oral doseDrug
Also called Comtan
30 minutes prior to the PET scan, patients will receive the 400mg oral dose of entacapone to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging.
| Study group | Role | What they receive |
|---|---|---|
| [18F]F-DOPA | Experimental | All patients will receive [18F]F-DOPA for PET imaging to measure pre-synaptic dopamine in the brain. Receives: Drug: [18F]FDOPA; Drug: Carbidopa 200mg oral dose; Drug: Entacapone 400mg oral dose |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differences in FDOPA uptake across patient populations
Specific FDOPA uptake, Ki, will be calculated via a reference Logan plot to provide voxelwise measurements of FDOPA uptake. Mean uptake will be assessed in brain regions-of-interest in 40 participants to assess potential differences across different autonomic failure-related diseases.
Measured: 95 minutes post-PET after start of PET imaging
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jan 2020
- Study start4 Feb 2020
- Primary completion1 Feb 2027 (estimated)
- Study completion1 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Autonomic FailureStudies 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 1
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Daniel Claassen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Daniel Claassen, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04246437
- Sponsor's protocol ID
- 192021
- Status last verified
- Mar 2026
- First submitted
- 25 Jan 2020
- Last updated
- 16 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- [18F]F-DOPA Imaging in Patients With Autonomic Failure
- ClinicalTrials.gov ID
- NCT04246437
- Acronym / sponsor ID
- 192021
- Conditions
- Autonomic Failure, Pure Autonomic Failure, Parkinson Disease, Multiple System Atrophy, Dementia With Lewy Bodies
- Keywords
- FDOPA, PET
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Daniel ClaassenUniversity, hospital or other
- Study start
- 4 Feb 2020 (actual)
- Primary completion
- 1 Feb 2027 (estimated)
- Study completion
- 1 Feb 2027 (estimated)
- First posted
- 29 Jan 2020 (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.
Alpha-synucleinopathies refer to age-related neurodegenerative and dementing disorders, characterized by the accumulation of alpha-synuclein in neurons and/or glia. The anatomical location of alpha-synuclein inclusions (Lewy Bodies) and the pattern of progressive neuronal death (e.g. caudal to rostral brainstem) give rise to distinct neurological phenotypes, including Parkinson's disease (PD), Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB). Common to these disorders are the involvement of the central and peripheral autonomic nervous system, where Pure Autonomic Failure (PAF) is thought (a) to be restricted to the peripheral autonomic system, and (b) a clinical risk factor for the development of a central synucleinopathy, and (c) an ideal model to assess biomarkers that predict phenoconversion to PD, MSA, or DLB. Such biomarkers would aid in clinical trial inclusion criteria to ensure assessments of disease- modifying strategies to, delay, or halt, the neurodegenerative process. One of these biomarkers may be related to the neurotransmitter dopamine (DA) and related changes in the substantia nigra (SN) and brainstem. [18F]F-DOPA is a radiolabeled substrate for aromatic amino acid decarboxylase (AAADC), an enzyme involved in the production of dopamine. Use of this radiolabeled substrate in positron emission tomography (PET) may provide insight to changes in monoamine production and how they relate to specific phenoconversions in PAF patients. Overall, this study aims to identify changes in dopamine production in key regions including the SN, locus coeruleus, and brainstem to distinguish between patients with PD, MSA, and DLB, which may provide vital information to predict conversion from peripheral to central nervous system disease.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| [18F]F-DOPA | Experimental | Drug: [18F]FDOPA, Drug: Carbidopa 200mg oral dose, Drug: Entacapone 400mg oral doseAll patients will receive [18F]F-DOPA for PET imaging to measure pre-synaptic dopamine in the brain. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients with a diagnosis if pure autonomic failure
- Patients with autonomic failure and possible PD, MSA, or DLB
- Healthy adults aged 18 and above
- Clinical exam confirming clinical designation
Key exclusion criteria (10 listed)
- Subjects who have any type of bioimplant activated by mechanical, electronic, or magnetic means (e.g., cochlear implants, pacemakers, neurostimulators, biostimulators, electronic infusion pumps, etc.), because such devices may be displaced or malfunction.
- Subjects who have any type of ferromagnetic bioimplant that could potentially be displaced.
- Subjects who have cerebral aneurysm clips.
- Subjects who may have shrapnel imbedded in their bodies (such as from war wounds), metal workers and machinists (potential for metallic fragments in or near the eyes).
- Subjects who are pregnant, because the effects of high field MRI on fetuses are not yet known.
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 |
|---|---|---|
| [18F]FDOPAPatients will receive a 3-D emission scan following a 6-8 mCi slow bolus injection of [18F]FDOPA over a 30 second period. Serial scans are started simultaneously with the bolus injection of radiotracer and are obtained for approximately 95 minutes. | Drug | [18F]F-DOPA |
| Carbidopa 200mg oral doseAlso: Lodosyn30 minutes prior to the PET scan, patients will receive the 200mg oral dose of carbidopa to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging. | Drug | [18F]F-DOPA |
| Entacapone 400mg oral doseAlso: Comtan30 minutes prior to the PET scan, patients will receive the 400mg oral dose of entacapone to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging. | Drug | [18F]F-DOPA |
Primary outcome
Differences in FDOPA uptake across patient populations
Time frame: 95 minutes post-PET after start of PET imaging
Specific FDOPA uptake, Ki, will be calculated via a reference Logan plot to provide voxelwise measurements of FDOPA uptake. Mean uptake will be assessed in brain regions-of-interest in 40 participants to assess potential differences across different autonomic failure-related diseases.
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 16 Mar 2026.
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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.
Kaitlyn O'Rourke, MS contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing [18F]FDOPA, Carbidopa 200mg oral dose and Entacapone 400mg oral dose in people with Autonomic Failure and Pure Autonomic Failure, run by Daniel Claassen 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 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: looking for participants now, as of the sponsor's last update on 16 Mar 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Daniel O Claassen, MD, MS (615-936-1007, daniel.claassen@vumc.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Differences in FDOPA uptake across patient populations (time frame: 95 minutes post-PET after start of PET imaging). 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 16 Mar 2026.