An Early Phase 1 interventional study of 11C-M503 PET and Brain MRI in Tauopathies, sponsored by University of Pennsylvania. Recruiting at 3 sites in United States. Open to participants aged 40 Years to 85 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-24.
Sponsored by University of Pennsylvania · Early Phase 1, Interventional, and Diagnostic
The current protocol is to determine the biodistribution, metabolism, excretion and brain uptake of 11C-M503. The goal of this radiotracer is to quantify alpha-synuclein that is abnormally deposited in the brain of people with Parkinson's disease (PD). Investigators will compare uptake in participants with PD versus participants with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP), as well as non-Parkinsonism volunteers. This multicenter project funded by an NIH U19 grant, is centered at U Pennsylvania (Penn, Grant PI: Robert Mach) in collaboration with U Pittsburgh (Pitt) (non-clinical site) Yale U, U of California at San Francisco (UCSF) and Washington University in St. Louis (WU). The University of Pennsylvania will act as the sIRB for this multi-center human subjects project and participants will be recruited from all sites.
The current protocol is to determine the biodistribution, metabolism, excretion and brain uptake of 11C-M503. The goal of this radiotracer is to quantify alpha-synuclein that is abnormally deposited in the brain of people with Parkinson's disease (PD). Investigators will compare uptake in participants with PD versus participants with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP), as well as non-Parkinsonism volunteers. This multicenter project funded by an NIH U19 grant, is centered at U Pennsylvania (Penn, Grant PI: Robert Mach) in collaboration with U Pittsburgh (Pitt) (non-clinical site) Yale U, U of California at San Francisco (UCSF) and Washington University in St. Louis (WU). The University of Pennsylvania will act as the sIRB for this multi-center human subjects project and participants will be recruited from all sites.
Participating clinical sites will recruit up to 20 people with PD, 20 with MSA, 10 with PSP and 20 healthy controls across sites with all participants ranging from 40-85 years old. Investigators will encourage equal participation of males and females.
This protocol will include up to 70 participants across all clinical sites (note that some of these participant scans performed at Penn may be used to calculate whole body biodistribution (BioD) and dosimetry. Investigators anticipate enrollment of up to 15-20 participants at each clinical site, who will undergo up to 120 minutes of dynamic brain PET scanning (with or without torso imaging, depending on the clinical site). A second IV or an arterial line may be placed, preferably in the arm contralateral to the side of injection, for blood metabolite analysis and/or radioactive counts at various times during the scanning session. These blood draw collections can be omitted at the discretion of the investigator. For participants at Penn that may be part of BioD analysis, urine may be collected at the end of the scan session. Participants will also undergo a research brain MRI that may be on a separate day from the PET.
PET imaging sessions will include an injection of ≤ 15 mCi (approximate range for most studies is anticipated to be 8 - 15 mCi at sites with a standard PET scanner or 3 - 15 at sites with a high sensitivity scanner) of 11C-M503. Biodistribution, metabolism, excretion and pilot brain uptake data will be collected and human dosimetry will be calculated from participants scanned at Penn who have whole body scans. PET scans will be collected to evaluate image quality and collect preliminary information on brain uptake of 11C-M503 in the disease cohorts and healthy controls. The safety of 11C-M503 will also be evaluated in all participants. Some participants (usually those with positive 11C-M503 PET scan) may also be asked to have an amyloid-beta (Aβ) PET scan to investigate specificity of 11C-M503.
75 studies on the registry are indexed under Tauopathies; 18 are open to participants now.
This study's planned enrollment of 70 is close to the median of 72 across 54 interventional studies indexed under Tauopathies.
Browse Tauopathies studies →University of Pennsylvania is the lead sponsor of 1,668 studies on the registry; 235 are open to participants now.
Of its 158 completed or terminated interventional studies of FDA-regulated products, 109 (69%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will undergo 11C-M503 PET scan, they may also have a brain MRI and Amyloid PET scan as well as neurological assessments.
Drug: 11C-M503 PET · Diagnostic Test: Brain MRI · Diagnostic Test: Amyloid PET · Behavioral: Neurological assessments
2 hour Positron Emission Tomography (PET) scan using new radiotracer 11C-M503
MRI scan of brain.
PET scan with Florbetaben F18 or 11C-PiB
Neurological assessments, including a video interview.
Organ Biodistribution or Dosimetry
Determine biodistribution of the radioactive investigational drug, 11C-M503 and calculate human dosimetry. A second IV or an arterial line may be placed in the arm contralateral to the side of injection for blood metabolite analysis and/or radioactive counts at various times during the scanning session. Biodistribution, metabolism, excretion and pilot brain uptake data will be collected and human dosimetry will be calculated.
Time frame: 4 weeks
PET Uptake of Tracer
Determine whether there is selective uptake of 11C-M503 in people with MSA compared to healthy volunteers, PD and PSP participants.
Time frame: 4 weeks
Adverse Events
Adverse events will be collected.
Time frame: 4 weeks
Plan to share: Yes — Early safety assessments including whole body dosimetry studies at Penn; coordinate patient selection criteria, centrally collect and serve all imaging and demographic data, coordinate tracer kinetic methods development and validation for human imaging, and coordinate all data to efficiently enable GO-NOGO decisions for candidate radiotracers. As a final check on diagnosis and specificity of candidate radiotracers, Investigators will request all patient participants to permit postmortem brain donation for autoradiography of relevant radiotracers on fresh frozen brain tissues. Additionally, this Core will interact with multiple ongoing studies with cohorts studying PD, MSA, PSP and FTD. Finally, a robust data sharing plan facilitates collaboration and use of support documents and imaging data.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: Data shared as participants are enrolled and then final clinical report after study is completed.
Access criteria: Dosimetry data. Dosimetry data for all compounds advanced to first-in-human trials will be provided on the website link for the Clinical Core. Since it is the intent of this U19 Center to provide information to the PET community on probes that have been validated in clinical research studies, these data will be provided once the CCOC has confirmed that a probe has met the validation criteria. This will include the results of dosimetry studies (organ, whole body, and EDE data) and, as requested, the organ radioactivity uptake, clearance curves and the dosimetry images in DICOM format. Imaging and Clinical Data. Links from the CCOC website will connect to XNAT and MARS to provide all de-identified clinical data, imaging data and related files including arterial blood sampling measurements. These data will be distributed upon request, as noted in the above policies for Data Sharing.
No publications or documents are linked to this record.
Started Feb 2024 (actual). Primary completion is estimated for Feb 2029, 60 months after the start.
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