Parkinson DiseaseFOX3NCT05516732
Serotonin Release in Premotor and Motor PD
An observational study of Parkinson Disease and Parkinson's, run by University of Exeter at 1 site in United Kingdom.
Trial summary
In this study, the investigators aim to provide a deeper understanding of Parkinson's disease and find a biomarker of Parkinson's disease. This is done using imaging scans called Positron Emission tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI). Read more about this study
- Who is it for?
- Ages 25 to 85 years
- Conditions the study is for
- Parkinson Disease, Parkinson's, Parkinson's Disease
- What is being tested?
- Positron Emission Tomography (PET) scan using CIMBI-36 tracer, Magnetic Resonance Imaging (MRI) Scan and Positron Emission Tomography (PET) scan using DASB tracer
- How many people
- 42 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Jul 2022to 30 Jun 2026
- Phase
- Observational
- 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 25 to 85 years
- All sexes
- Adult, Older adult
Study population: A cohort of carriers of genetic mutations for familial forms of Parkinson's Disease, Idiopathic Parkinson's Disease patients, and previously collected data from healthy controls
Who may be able to join
- Subjects must understand the nature of the study and must provide signed and dated written HRA-approved informed consent in accordance with local regulations before any protocol-specific screening procedures are performed;
- Males and females, age 25-85 years, inclusive;
- Women of child-bearing potential must use protocol-defined contraceptive measures and must have a negative β-hCG test at screening. For sexually active subjects (except females of non-childbearing potential-e.g., at least 2 years postmenopausal or surgically sterile), condoms should be used in addition to other birth control methods for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. These patients must be willing to remain on their current form of contraception for the duration of the study. All male subjects must agree to refrain from donating sperm for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. Sexually active male subjects must agree to use condoms to protect their partners from becoming pregnant for the duration of the study and for 3 months after the last administration of PET or SPECT ligands (i.e. for 15 consecutive months following baseline PET and SPECT scans); agree to ensure that they and their partners are routinely using a medically approved contraceptive method. It is important that male subjects not impregnate others for the duration of the study and for 3 months after the last administration of PET or SPECT ligands;
- Able and willing to participate in all scheduled evaluations, abide by all study restrictions, and complete all required tests and procedures;
- Adequate visual and auditory acuity to complete the psychological testing;
- In the opinion of the investigator, the subject must be considered likely to comply with the study protocol and to have a high probability of completing the study.
Who cannot join
- Subjects lacking capacity according to investigator judgement;
- Subjects taking serotonin acting drugs such as antidepressants (i.e. tricyclic or selective serotonin reuptake inhibitors etc.);
- Pregnancy or breastfeeding or intent to become pregnant in the next 18 months;
- Subjects with current or a recent history of drug or alcohol abuse/dependence;
- Subjects who have other neurological disorders and known intracranial co-morbidities such as stroke, hemorrhage, space-occupying lesions;
- Presence of any clinically significant medical condition (including cardiovascular, respiratory, cerebrovascular, hematological, hepatic, renal, gastrointestinal, or other disease) that, based on the judgment of the investigator, is clinically unstable, is likely to deteriorate during the course of the study, could put the patient at risk because of participation in the study, could affect the subject's ability to complete the study, or could influence the study results;
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- History of suicidal behaviour or active suicidal ideation;
- Within 1 year prior to screen or between screen and baseline (Day -1), any of the following: myocardial infarction; hospitalization for congestive heart failure; hospitalization for, or symptoms of, unstable angina; or syncope not related to PD;
- History or presence of renal disease or impaired renal function;
- Clinically important infection (e.g., chronic, persistent, or acute infection) within 30 days prior to screen or between screen and baseline (Day -1);
- History of cancer within the last 5 years, with the exception of nonmetastatic basal cell carcinoma of the skin;
- Clinically significant blood clotting or bleeding disorder, including clinically significant abnormal findings in laboratory assessments of coagulation or hematology;
- Use of antipsychotic medication within 3 months prior to screen or between screen and baseline (Day -1);
- Use of any anticoagulant within 30 days prior to baseline and follow-up PET scans;
- Use of any oral corticosteroid within 30 days prior to baseline and follow-up PET scans;
- Use of metoclopramide within 30 days prior to baseline and follow-up (Day -1);
- Use of any thyroid medication within 30 days prior to baseline and follow-up (Day -1);
- Regular use (e.g., taken > 3 days/week) of narcotic pain medications within 30 days prior to baseline and follow-up (Day -1);
- Presence of any of the following MRI contraindications: pacemaker; cardiac defibrillator; spinal cord or vagus nerve stimulator; aneurysm clip; artificial heart valve; recent coronary or carotid stent; ear implant; CSF shunt; other implanted medical device (e.g., Swan-Ganz catheter, insulin pump); or metal fragments or foreign objects in the eyes, skin, or body;
- Negative modified Allen test in both hands, unless the brachial artery is used for arterial cannulation;
- Claustrophobia or history of back pain that makes prolonged laying on the PET or MRI scanner intolerable;
- History of severe skin allergy;
- Patients who had previous surgery for PD (including but not limited to deep brain stimulation [DBS] or cell transplantation);
- Patients who are treated with duodopa or apomorphine;
- Initiation or change in pharmacologic therapy for symptoms of PD within 30 days prior to screen or between screen and baseline and follow-up (Day -1).
- GDS score greater than or equal to 10 (GDS score of 5 - 9 requires Investigator discretion to enter study).
- STAI Form Y-1 greater than or equal to 54 requires Investigator discretion to enter study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
University Of Exeter
Exeter, Devon, EX1 2LU
Marios Politis, Professor, 07503 741242, m.politis@exeter.ac.uk
Edoardo de Natale, Dr, 07503 741242, e.de-natale@exeter.ac.uk
About this study
Official title: Evaluation of Serotonergic Neurotransmission in Premotor and Motor Parkinson's Disease.
In this study, the investigators aim to provide a deeper understanding of Parkinson's disease and find a biomarker of Parkinson's disease. This is done using imaging scans called Positron Emission tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI). The findings will provide a deeper understanding of the brain changes in Parkinson's disease. More importantly, this study will help with the discovery and development of new medications aiming to delay progression of Parkinson's disease symptoms
Read the detailed description
The purpose of this study is to find a biomarker for Parkinson's disease (PD). A biomarker is an indicator of the presence of a disease, that can be measured, and that is able to give information about the progression, or severity, of it.
The study visits will take place in London. There are three locations on Hammersmith hospital campus, that are located near to each other. The NIHR Imperial Clinical Research Facility and Invicro London for clinical and MRI and PET assessments, and Imperial Healthcare Nuclear Medicine Department for the SPECT scan.
Participants will attend 5 visits in a 3 month period. These visits include an initial consent and assessment visit where some blood samples will also be taken. The second visit involves a PET scan with the tracer DASB along with an MRI scan. The third visit involves two PET scans one in the morning, with CIMBI tracer, an injection of Dexamphetamine, and then a second with CIMBI tracer to make a comparison. The fourth visit involves a SPECT scan, and the fifth visit is optional and would be for a lumbar puncture visit. Each visit will last around 6 hours.
- Conditions
- Parkinson Disease, Parkinson's, Parkinson's Disease, Neurodegenerative Diseases, Neurodegeneration, Positron Emission Tomography
- Being tested
- Positron Emission Tomography (PET) scan using CIMBI-36 tracer, Magnetic Resonance Imaging (MRI) Scan, Positron Emission Tomography (PET) scan using DASB tracer, FP-CIT Single-photon Emission Computed Tomography (SPECT) scan, Lumbar puncture
- Medical subject headings
- Parkinson Disease, Neurodegenerative Diseases, Nerve Degeneration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Positron Emission Tomography (PET) scan using CIMBI-36 tracerOther
This scan creates images of regional serotonin release in by using a tracer compound called CIMBI to highlight the brains capacity to release serotonin.
Magnetic Resonance Imaging (MRI) ScanOther
MRI (magnetic resonance imaging) uses magnets alongside radio waves to create pictures of the brain
Positron Emission Tomography (PET) scan using DASB tracerOther
To create images of the brain using a tracer called DASB, which is a highly selective for serotonin transporters, this highlights serotonin terminals and neurons in the brain.
FP-CIT Single-photon Emission Computed Tomography (SPECT) scanOther
A single-photon emission computerized tomography (SPECT) scan allows analysis of brain function by creating 3D Pictures using compounds called tracers.
Lumbar punctureOther
A lumbar puncture invovles a thin needle is inserted between the bones in your lower spine using local anaesthetic. This allows the collection of Cerebrospinal fluid ( CSF)
| Study group | Role | What they receive |
|---|---|---|
| SNCA (Alpha-synuclein gene) | PET and SPECT molecular imaging and MRI; Clinical investigation and computerized neuropsychological testing; Collection of blood, urine and CSF biomarkers of PD pathology Receives: Other: Positron Emission Tomography (PET) scan using CIMBI-36 tracer; Other: Magnetic Resonance Imaging (MRI) Scan; Other: Positron Emission Tomography (PET) scan using DASB tracer; Other: FP-CIT Single-photon Emission Computed Tomography (SPECT) scan; Other: Lumbar puncture | |
| Idiopathic Parkinson's Disease | PET and SPECT molecular imaging and MRI; Clinical investigation and computerized neuropsychological testing; Collection of blood, urine and CSF biomarkers of PD pathology Receives: Other: Positron Emission Tomography (PET) scan using CIMBI-36 tracer; Other: Magnetic Resonance Imaging (MRI) Scan; Other: Positron Emission Tomography (PET) scan using DASB tracer; Other: FP-CIT Single-photon Emission Computed Tomography (SPECT) scan; Other: Lumbar puncture |
What is being measured
The primary outcome is the main question the study is designed to answer.
DASB (a marker of Serotonin transporter) used to quantify in vivo pathology of serotonin
To quantify serotonergic pathology with [11C]3-amino-4-(2- imethylaminomethylphenylsulfanyl)-benzonitrile (DASB) Positron Emission Tomography (PET)
Measured: 3 Weeks
SPECT to measure brain molecular pathology
To quantify serotonergic pathology with [11C]DASB PET and dopaminergic pathology with Single-photon Emission Computed Tomography (SPECT)
Measured: 3 Weeks
Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) to view structural and microstructural changes and structural connectivity.
Measured: 3 Weeks
CIMBI to measure serotonin release
CIMBI-36 can be interpreted to show serotonin release capacity both quantifiably and locational.
Measured: 3 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Aug 2022
- Study start1 Jul 2022
- Primary completion30 Jun 2026 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 42 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Exeter
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marios M Politis, Professor, Principal investigator, University of Exeter
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05516732
- Sponsor's protocol ID
- 2020-21-16
- Acronym
- FOX3
- Status last verified
- Oct 2025
- First submitted
- 24 Aug 2022
- Last updated
- 7 Oct 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: to be decided
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Serotonergic Neurotransmission in Premotor and Motor Parkinson's Disease.
- ClinicalTrials.gov ID
- NCT05516732
- Acronym / sponsor ID
- FOX3 / 2020-21-16
- Conditions
- Parkinson Disease, Parkinson's, Parkinson's Disease, Neurodegenerative Diseases, Neurodegeneration, Positron Emission Tomography
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 42 participants (estimated)
- Lead sponsor
- University of ExeterUniversity, hospital or other
- Study start
- 1 Jul 2022 (actual)
- Primary completion
- 30 Jun 2026 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 26 Aug 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.
In this study, the investigators aim to provide a deeper understanding of Parkinson's disease and find a biomarker of Parkinson's disease. This is done using imaging scans called Positron Emission tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI). The findings will provide a deeper understanding of the brain changes in Parkinson's disease. More importantly, this study will help with the discovery and development of new medications aiming to delay progression of Parkinson's disease symptoms
Detailed description
The purpose of this study is to find a biomarker for Parkinson's disease (PD). A biomarker is an indicator of the presence of a disease, that can be measured, and that is able to give information about the progression, or severity, of it.
The study visits will take place in London. There are three locations on Hammersmith hospital campus, that are located near to each other. The NIHR Imperial Clinical Research Facility and Invicro London for clinical and MRI and PET assessments, and Imperial Healthcare Nuclear Medicine Department for the SPECT scan.
Participants will attend 5 visits in a 3 month period. These visits include an initial consent and assessment visit where some blood samples will also be taken. The second visit involves a PET scan with the tracer DASB along with an MRI scan. The third visit involves two PET scans one in the morning, with CIMBI tracer, an injection of Dexamphetamine, and then a second with CIMBI tracer to make a comparison. The fourth visit involves a SPECT scan, and the fifth visit is optional and would be for a lumbar puncture visit. Each visit will last around 6 hours.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SNCA (Alpha-synuclein gene) | – | Other: Positron Emission Tomography (PET) scan using CIMBI-36 tracer, Other: Magnetic Resonance Imaging (MRI) Scan, Other: Positron Emission Tomography (PET) scan using DASB tracer, Other: FP-CIT Single-photon Emission Computed Tomography (SPECT) scan, Other: Lumbar puncturePET and SPECT molecular imaging and MRI; Clinical investigation and computerized neuropsychological testing; Collection of blood, urine and CSF biomarkers of PD pathology |
| Idiopathic Parkinson's Disease | – | Other: Positron Emission Tomography (PET) scan using CIMBI-36 tracer, Other: Magnetic Resonance Imaging (MRI) Scan, Other: Positron Emission Tomography (PET) scan using DASB tracer, Other: FP-CIT Single-photon Emission Computed Tomography (SPECT) scan, Other: Lumbar puncturePET and SPECT molecular imaging and MRI; Clinical investigation and computerized neuropsychological testing; Collection of blood, urine and CSF biomarkers of PD pathology |
Who may qualify
- Ages
- 25 to 85 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- A cohort of carriers of genetic mutations for familial forms of Parkinson's Disease, Idiopathic Parkinson's Disease patients, and previously collected data from healthy controls
Key inclusion criteria (6 listed)
- Subjects must understand the nature of the study and must provide signed and dated written HRA-approved informed consent in accordance with local regulations before any protocol-specific screening procedures are performed;
- Males and females, age 25-85 years, inclusive;
- Women of child-bearing potential must use protocol-defined contraceptive measures and must have a negative β-hCG test at screening. For sexually active subjects (except females of non-childbearing potential-e.g., at least 2 years postmenopausal or surgically sterile), condoms should be used in addition to other birth control methods for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. These patients must be willing to remain on their current form of contraception for the duration of the study. All male subjects must agree to refrain from donating sperm for the duration of the study and for 3 months after the last administration of PET or SPECT ligands. Sexually active male subjects must agree to use condoms to protect their partners from becoming pregnant for the duration of the study and for 3 months after the last administration of PET or SPECT ligands (i.e. for 15 consecutive months following baseline PET and SPECT scans); agree to ensure that they and their partners are routinely using a medically approved contraceptive method. It is important that male subjects not impregnate others for the duration of the study and for 3 months after the last administration of PET or SPECT ligands;
- Able and willing to participate in all scheduled evaluations, abide by all study restrictions, and complete all required tests and procedures;
- Adequate visual and auditory acuity to complete the psychological testing;
Key exclusion criteria (27 listed)
- Subjects lacking capacity according to investigator judgement;
- Subjects taking serotonin acting drugs such as antidepressants (i.e. tricyclic or selective serotonin reuptake inhibitors etc.);
- Pregnancy or breastfeeding or intent to become pregnant in the next 18 months;
- Subjects with current or a recent history of drug or alcohol abuse/dependence;
- Subjects who have other neurological disorders and known intracranial co-morbidities such as stroke, hemorrhage, space-occupying lesions;
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 |
|---|---|---|
| Positron Emission Tomography (PET) scan using CIMBI-36 tracerThis scan creates images of regional serotonin release in by using a tracer compound called CIMBI to highlight the brains capacity to release serotonin. | Other | Idiopathic Parkinson's Disease, SNCA (Alpha-synuclein gene) |
| Magnetic Resonance Imaging (MRI) ScanMRI (magnetic resonance imaging) uses magnets alongside radio waves to create pictures of the brain | Other | Idiopathic Parkinson's Disease, SNCA (Alpha-synuclein gene) |
| Positron Emission Tomography (PET) scan using DASB tracerTo create images of the brain using a tracer called DASB, which is a highly selective for serotonin transporters, this highlights serotonin terminals and neurons in the brain. | Other | Idiopathic Parkinson's Disease, SNCA (Alpha-synuclein gene) |
| FP-CIT Single-photon Emission Computed Tomography (SPECT) scanA single-photon emission computerized tomography (SPECT) scan allows analysis of brain function by creating 3D Pictures using compounds called tracers. | Other | Idiopathic Parkinson's Disease, SNCA (Alpha-synuclein gene) |
| Lumbar punctureA lumbar puncture invovles a thin needle is inserted between the bones in your lower spine using local anaesthetic. This allows the collection of Cerebrospinal fluid ( CSF) | Other | Idiopathic Parkinson's Disease, SNCA (Alpha-synuclein gene) |
Primary outcome
DASB (a marker of Serotonin transporter) used to quantify in vivo pathology of serotonin
Time frame: 3 Weeks
To quantify serotonergic pathology with [11C]3-amino-4-(2- imethylaminomethylphenylsulfanyl)-benzonitrile (DASB) Positron Emission Tomography (PET)
SPECT to measure brain molecular pathology
Time frame: 3 Weeks
To quantify serotonergic pathology with [11C]DASB PET and dopaminergic pathology with Single-photon Emission Computed Tomography (SPECT)
Magnetic Resonance Imaging (MRI)
Time frame: 3 Weeks
Magnetic Resonance Imaging (MRI) to view structural and microstructural changes and structural connectivity.
CIMBI to measure serotonin release
Time frame: 3 weeks
CIMBI-36 can be interpreted to show serotonin release capacity both quantifiably and locational.
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 Oct 2025.
- University of Exeter brief project information webpageLink provided by the sponsor.
- Individual participant dataSharing planned: Undecided. to be decided
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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.
Marios M Politis, Professor principal investigator
University of Exeter
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Parkinson Disease and Parkinson's, run by University of Exeter at 1 site in United Kingdom.
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 6 inclusion and 27 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 Oct 2025. 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 Kingdom. 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.
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 Marios Politis, Professor (07503741242, M.Politis@exeter.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
DASB (a marker of Serotonin transporter) used to quantify in vivo pathology of serotonin (time frame: 3 Weeks). The study lists 4 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 Oct 2025; AzTrials last refreshed its copy on 6 Nov 2026.