Investigating PDE4B in Major Depressive Disorder with [18F]PF-06445974 PET
This study is looking into Major Depressive Disorder (MDD) and how it might be linked to an enzyme called PDE4B in the brain. Researchers want to see if people experiencing a major depressive episode (MDE) have lower levels of PDE4B. You might be eligible if you are 18-70 years old and have MDD. The study involves receiving an injection of [18F]PF-06445974, followed by a PET scan (a type of imaging test), and a lung scan. Some participants will also take apremilast, a drug, to see if it affects PDE4B. The main goal is to measure the amount of PDE4B in the brain and see if it's lower in people with MDD. The study plans to enroll 108 participants, but its current status is unclear.
- Study design
- This is an interventional study with a planned enrollment of 108 participants. The study aims to compare PDE4B levels in individuals with MDD to healthy volunteers.
- What's involved
- Participants will receive an intravenous (IV) injection of [18F]PF-06445974, undergo a PET scan, and have a lung scan. Some participants will also take apremilast orally.
- Compensation
- Not stated in the trial record.
- Follow-up
- The primary endpoint, distribution volume, will be measured at 36 months.
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NCT05703685
[18F]PF-06445974 to Image PDE4B in Major Depressive Disorder Using PET
Recruiting
PHASE1Ages 18–70InterventionalDiagnosticNational Institute of Mental Health (NIMH)Government-funded
~108 participants
Updated 2026-08-17 on ClinicalTrials.gov
What's tested:Lung scanApremilast18F-PF-06445974
At a glance
Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
To measure distribution volume
Measured over 36 months
Conditions
Where it's being run
1 sites across 1 statesMaryland1
Study leadership
- Robert B Innis, M.D. · PRINCIPAL_INVESTIGATOR · National Institute of Mental Health (NIMH)
Who to contact
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Do you actually qualify for this trial?
Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.
Eligibility criteria
Inclusion
18 to 70 years of age.
Female participants of childbearing potential must be using a medically acceptable means of contraception.
Be in good general health as evidenced by medical history and physical examination. Stable medical conditions as assessed by their primary care provider (PCP) and/or in-house clinician are permitted to join the study.
Each participant must have a level of understanding sufficient to agree to all required tests and examinations and sign an informed consent document.
All participants must have undergone a screening assessment under protocol 01-M-0254, The Evaluation of Patients with Mood and Anxiety Disorders and Healthy Participants .
Participants must fulfill DSM-5 criteria for major depression (MDD) without psychotic features, as based on clinical assessment and structured diagnostic interview (SCID-P).
Participants must have an initial score on the MADRS \>= 18 or HAM-D \>= 15 within one week of study entry.
Participants must be experiencing an MDE lasting at least four weeks.
All MDD participants must have a PCP or psychiatrist in the community.
Participants must have their radial artery pulse checked for the presence of adequate ulnar collateral flow and the absence of any metal or foreign objects in both wrists.
Participants must agree to adhere to the lifestyle considerations.
Aged 18 to 70 years old.
Female participants of childbearing potential must be using a medically acceptable means of contraception.
Able to provide informed consent.
Be in good general health, as evidenced by medical history and physical examination, and have no cognitive impairment.
Be enrolled in 01M0254, The Evaluation of Participants with Mood and Anxiety Disorders and Healthy Volunteers or 17M0181, Recruitment and Characterization of Healthy Research Volunteers for NIMH Intramural Studies .
Have their radial artery pulse checked for the presence of adequate ulnar collateral flow and the absence of any metal or foreign objects in both wrists.
Agree to adhere to the lifestyle considerations.
Exclusion
Clinically significant abnormalities on EKG or laboratory testing. This includes CBC and acute care panel (Na, K, Cl, CO2, creatinine, glucose, urea nitrogen). Any lab value that is two-times the upper limit or even lower values in the investigator s judgment. Creatinine level \>1.3 mg/dL.
Participants must be free of all prohibited medications for at least two weeks (5 weeks for aripiprazole, brexpiprazole, fluoxetine) prior to screen visit. These medications include antidepressants, antipsychotics, anxiolytics, psychotropic drugs not otherwise specified
Current psychotic features, a diagnosis of schizophrenia or any other psychotic disorder as defined in the DSM-5.
Participants with a history of psychiatric inpatient hospitalization within the past year.
Participants who, in the investigator s judgment, pose a current serious suicidal or homicidal risk.
Participants with suicidal ideation within the past 6 months.
Participants with suicidal behavior within the past 12 months.
Participants who have a history of aggressive behavior towards others.
Participants who have an unstable medical condition that, in the opinion of the investigators, makes participation unsafe (e.g., an active infection or untreated malignancy).
HIV infection.
Pregnancy.
Are unable to travel to the NIH.
Have recent exposure to radiation related to research (e.g., PET from other research) that, when combined with this study, would be above the allowable limits.
Have an inability to lie flat and/or lie still on the camera bed for at least two hours, including claustrophobia, overweight greater than the maximum for the scanner, and uncontrollable behavioral symptoms, which will be screened by an interview with the participant during the screening visit.
Are unable to have an MRI scan (e.g., because of pacemakers or other implanted electrical devices, brain stimulators, dental implants, aneurysm clips (metal clips on the wall of a large artery), metallic prostheses (including metal pins and rods, heart valves, and cochlear implants), permanent eyeliner, implanted delivery pumps, shrapnel fragments, or metal fragments in the eye.
Be NIMH staff or an NIH employee who is a subordinate/relative/co-worker of the investigators.
Clinically significant abnormalities on EKG or laboratory testing. This includes CBC and acute care panel (Na, K, Cl, CO2, creatinine, glucose, urea nitrogen).
Participants must be free of all prohibited medications or at least two weeks (5 weeks for aripiprazole, brexpiprazole, fluoxetine) prior to screen visit. These medications include antidepressants, antipsychotics, anxiolytics, psychotropic drugs not otherwise specified (including herbal products), and sedatives/hypnotics.
Participants who have a history of major depressive disorder.
Participants who have an unstable medical condition that, in the opinion of the investigators, makes participation unsafe (e.g., an active infection or untreated malignancy).
HIV infection.
Pregnancy.
Are unable to travel to the NIH.
Have recent exposure to radiation related to research (e.g., PET from other research) that, when combined with this study, would be above the allowable limits.
Have an inability to lie flat and/or lie still on the camera bed for at least two hours, including claustrophobia, overweight greater than the maximum for the scanner, and uncontrollable behavioral symptoms, which will be screened by an interview with the participant during the screening visit.
Are unable to have an MRI scan (e.g., because of pacemakers or other implanted electrical devices, brain stimulators, dental implants, aneurysm clips (metal clips on the wall of a large artery), metallic prostheses (including metal pins and rods, heart valves, and cochlear implants), permanent eyeliner, implanted delivery pumps, shrapnel fragments, or metal fragments in the eye.
Use of cytochrome P450 enzyme inducers (e.g. rifampin, phenobarbital, carbamazepine, phenytoin).
Be NIMH staff or an NIH employee who is a subordinate/relative/co-worker of the investigator.
What this trial measures
- To measure distribution volume36 months
Target quantification