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Normal PhysiologyNCT03324646

Evaluation of a Novel PET Radioligand to Image Cyclooxygenase-1 (COX-1)

An observational study of Normal Physiology, run by National Institute of Mental Health (NIMH) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Background: A radioligand is a radioactive substance that is used to diagnose diseases. A new ligand is called [11C]PS13. This has a small amount of radioactivity that can be detected by a positron emission tomography (PET) scan. Read more about this study

Who is it for?
Ages 18 to 99 years
Conditions the study is for
Normal Physiology
What is being tested?
[11C]PS13
How many people
52 participants
Where
1 siteUnited States
Study dates
3 Oct 2017to 30 Jan 2024
Phase
Observational
Are there results?
None posted in the registry

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 to 99 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Community sample

Who may be able to join

  • Aged 18 years or older.
  • Able to provide informed consent.
  • Medically and psychiatrically healthy.
  • Enrolled in 01-M-0254 The Evaluation of Participants with Mood and Anxiety Disorders and Healthy Volunteers or 17-M-0181, Recruitment and Characterization of Healthy Research Volunteers for NIMH Intramural Studies".

Who cannot join

  • Because non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX-1 and/or COX-2, subjects should not have taken NSAIDs for two weeks prior to the PET scan. In addition, aspirin must not have been taken in the prior month, as aspirin irreversibly inhibits COX.
  • Clinically significant laboratory abnormalities based on tests performed under screening protocol 01-M-0254 or 17-M-0181 and specified in Section 4.c Screening.
  • Any current Axis I diagnosis, based on interview and self-reporting performed under screening protocol 01-M-0254 or 17-M-0181.
  • HIV infection.
  • History of medical or neurologic illness or injury with the potential to affect study data interpretation.
  • Recent exposure to radiation related to research (i.e. PET from other research) that, when combined with this study, would be above the allowable limits.
Show all 25Show fewer
  • Inability to lie flat on camera bed for at least two hours.
  • Pregnancy or breastfeeding.
  • Participants must not have substance use disorder or alcohol use disorder. However, alcohol or cannabis use by themselves are not
  • exclusion criteria, unless that use impairs function of daily life..
  • Current use of psychiatric medications.
  • NIMH employees and staff or an NIH employee who is a subordinate/relative/co-worker of the investigators.
  • Because aspirin and celecoxib require an acidic environment to be absorbed in the stomach, we will exclude those who have taken proton pump inhibitor (PPI) drugs, H-2 receptor antagonist drugs, and antacid drugs in the last two weeks.
  • additional contraindications to taking COX-1 or COX-2 inhibitors include:
  • history of hypersensitivity reaction to COX inhibitors history of aspirin- or NSAID-induced asthma.
  • history of upper or lower gastrointestinal bleeding, gastritis, peptic ulcer disease, or gastroesophageal reflux disease (GERD).
  • coagulation disorder.
  • thrombocytopenia.
  • G6PD deficiency.
  • history of gout.
  • history of hepatic or renal impairment.
  • history of cardiovascular disease or presence of cardiovascular risk factors such as hypertension.
  • Artery check for art line
  • Unable to have an MRI scan
  • NIH employees are eligible to participate. NIMH employee participation is guided by intramural institute policy.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • National Institutes of Health Clinical Center

    Bethesda, Maryland, 20892

Other trials in United States

About this study

Background:

A radioligand is a radioactive substance that is used to diagnose diseases. A new ligand is called [11C]PS13. This has a small amount of radioactivity that can be detected by a positron emission tomography (PET) scan. If this ligand works well in this study, researchers may be able to use it to better understand and diagnose brain disorders.

Read more

Objectives:

To evaluate if [11C]PS13 can measure its receptor, which is involved in inflammation. To see if researchers get the same results when scanning a person twice.

Eligibility:

Healthy people ages 18 and older who are in Protocol 01-M-0254.

Design:

This study requires three visits of 2-5 hours each.

Participants will have 2 PET scans with [11C]PS13.

A needle will guide a small plastic tube (catheter) into an arm vein. The needle will be removed, leaving only the catheter in the vein. The ligand will be injected through the catheter.

The PET scanner is shaped like a doughnut. Participants will lie on a bed that slides in and out of the scanner.

Participants will wear a molded a plastic mask that fits the head.

Another catheter will be put into an artery at the wrist or elbow area.

Vital signs will be monitored during the PET scan. Participants will have a test during the PET scan to monitor heart function.

Participants will have blood and urine tests.

Participants will have 1 magnetic resonance imaging (MRI) scan. The MRI scanner is a metal cylinder surrounded by a strong magnetic field. Participants will lie on a table that slides in and out of the cylinder.

Read the detailed description

Objective

The cyclooxygenase (COX) system is implicated in the pathophysiology of brain diseases, including Alzheimer s disease and depression, and is a potential biomarker for neuroinflammation. COX is the rate-limiting enzyme in the synthesis of prostaglandins from arachidonic acid and exists as two primary isoforms COX-1 and COX-2. Our laboratory recently developed [(11)C]PS13, a novel PET ligand to selectively image COX-1, and initial PET scans in monkey demonstrated that [11C]PS13 is a promising ligand.

This study has two primary objectives. First, we will determine whether the uptake of [(11)C]PS13 in brain and periphery reflects the distribution of COX-1, as demonstrated by blocking with a COX-1 preferential drug (aspirin or ketoprofen) and/or no effect with a COX-2 selective drug (celecoxib). Second, we will measure the test/retest reproducibility of brain uptake quantified by compartmental modeling and using arterial and/or venous blood samples.

Study Population

Healthy adult volunteers (aged 18 years or older) will have either whole body imaging (n = 41) or brain imaging (n = 20).

Design

Phase 1: We will begin with whole body scanning in a single human subject using up to 10 mCi. The aim of this first scan will be to detect a tracer that disproportionately accumulates in a single radiosensitive organ, such as the gonads. If we confirm that radioactivity is fairly widely distributed in the body, higher activities may be injected.

Phase 2:Thirty healthy subjects will have three whole body imaging PET scans using 20 mCi of [11C]PS13. Scan 1 will serve as the baseline scan for comparison to enzyme occupancy studies and will provide dosimetry information. Scan 2 will be an enzyme occupancy study using the COX-2 selective antagonist celecoxib. Scan 3 will be an enzyme occupancy study using the COX-1 preferential antagonist aspirin. Ten healthy subjects will have two whole body imaging PET scans using 20 mCi of [11C]PS13. Scan

1 will serve as the baseline scan, and scan 2 will be an enzyme occupancy study using another potent COX-1 antagonist ketoprofen.

Phase 3: We will perform 15 test retest kinetic brain imaging PET studies with arterial and/or venous blood sampling and 5 test retest brain PET studies with both arterial and venous blood sampling, using a 20 mCi dose of [(11)C]PS13.

Outcome Measures

For whole body imaging, organ uptake will be quantified as a Standardized Uptake Value (SUV), which normalizes for injected activity and body weight. Blockade by aspirin, ketoprofen, and celecoxib will be expressed as a percentage of the baseline scan in each subject and plotted relative to the plasma concentration of the drug at time of the PET scan. For dedicated brain imaging, uptake will be quantified as distribution volume (VT) calculated with compartmental modeling and serial concentrations of parent radioligand in arterial and/or

venous plasma.

Being tested
[11C]PS13
Keywords
Research, Brain, Inflammation, Natural History
Medical subject headings
Inflammation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • [11C]PS13Drug

    A novel PET ligand to selectively image COX-1

Study groups in NCT03324646
Study groupRoleWhat they receive
controlshealthy subjects
Receives: Drug: [11C]PS13

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. PET tracer update

    For whole body imaging, organ uptake will be quantified as a Standardized Uptake Value (SUV), which normalizes for injected activity and body weight. Blockade by aspirin, ketoprofen, and celecoxib will be expressed as a percentage of the baseline scan in each subject and plotted relative to the plasma concentration of the drug at time of the PET scan. For dedicated brain imaging, uptake will be quantified as distribution volume (VT) calculated with compartmental modeling and serial concentrations of parent radioligand in arterial and/or venous plasma.

    Measured: during PET scan

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Oct 2017
  2. Study start3 Oct 2017
  3. Primary completion11 Sep 2020
  4. Study completion30 Jan 2024

Resources

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
Other
Enrolment
52 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03324646
Sponsor's protocol ID
170179
Other IDs
17-M-0179
Status last verified
Aug 2025
First submitted
27 Oct 2017
Last updated
15 Aug 2025
Results posted
No
FDA-regulated drug
Yes
FDA-regulated device
No

Publications

  • Parcon P, Scrabis M, Norgaard M, Galassi A, Zanotti-Fregonara P, Liow JS, Innis RB, Kim MJ. [11C]PS13 PET shows that age is positively correlated with constitutively expressed cyclooxygenase-1 in the brain. J Cereb Blood Flow Metab. 2026 May 5:271678X261444895. doi: 10.1177/0271678X261444895. Online ahead of print.

    PubMed 42083927
  • Kim MJ, Lee JH, Juarez Anaya F, Hong J, Miller W, Telu S, Singh P, Cortes MY, Henry K, Tye GL, Frankland MP, Montero Santamaria JA, Liow JS, Zoghbi SS, Fujita M, Pike VW, Innis RB. First-in-human evaluation of [11C]PS13, a novel PET radioligand, to quantify cyclooxygenase-1 in the brain. Eur J Nucl Med Mol Imaging. 2020 Dec;47(13):3143-3151. doi: 10.1007/s00259-020-04855-2. Epub 2020 May 12.

    PubMed 32399622

Questions about this trial

What is this clinical trial studying?

An observational study of Normal Physiology, run by National Institute of Mental Health (NIMH) 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 25 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: finished, as of the sponsor's last update on 15 Aug 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 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.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

PET tracer update (time frame: during PET scan). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03324646, which also lists 2 linked publications.

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 15 Aug 2025.

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