Assessment of 11C-JMJ-129 for Imaging PDE4D in Brain and Whole Body of Healthy Volunteers

Background: PDE4D is a protein in the body that plays a role in thinking and depression. This protein may play a major role in disorders such as Alzheimer disease or major depressive disorder. To learn more about these disorders, researchers want to be able to detect levels of PDE4D in the brain. 11C-JMJ-129 is a new radiotracer (a radioactive substance that highlights parts of the body during imaging scans) that was developed to attach only to PDE4D. However, early human studies showed that the tracer may break down in the body and create byproducts that interfere with the brain signal, making the results harder to interpret. This study will test whether a medication called disulfiram can improve PET imaging with 11C-JMJ-129. Disulfiram blocks an enzyme in the body that may be responsible for breaking down the tracer. By reducing this breakdown, the study aims to improve the quality and accuracy of brain images. The results may help researchers better measure PDE4D in the brain and support future studies of brain disorders. Objective: To test the new radiotracer 11C-JMJ-129, with and/or without disulfiram pretreatment during imaging scans in healthy volunteers. Eligibility: Healthy people aged 18 years and older who had a screening assessment under protocol 01-M-0254. Design: Participants will have 1 to 4 clinic visits. Participants will be screened. They will have a physical exam. They will have blood tests and a test of their heart function. Participants will undergo 1 or more of these scans: A positron emission tomography (PET) scan of the whole body. The radiotracer will be injected through a tube placed in a vein in the arm. Participants will lie on a table while a donut-shaped machine passes over them. Blood will be drawn from the arm during this scan. In Phase 5, disulfiram (500 mg orally) will be administered approximately 20 hours before the post-disulfiram PET scan A magnetic resonance imaging (MRI) scan of the brain. Participants will lie on a table that slides into a tube. A PET scan of the brain. These participants will be injected with the radiotracer. They will lie on a table with their head in the scanner. Participants will be called within 3 days after each PET scan for a check on their health.

NCT Number	NCT06874205
Lead Sponsor	National Institute of Mental Health (NIMH)
Conditions	Healthy
Enrollment	40 participants
Start Date	2025-04-11
Primary Completion	2028-02-22 (estimated)
Study Completion	2029-02-05 (estimated)
Updated on ClinicalTrials.gov	2026-07-07