Evaluation of a Novel Positron Emission Tomography (PET Radiotracer for TARP Gamma-8
- Conditions
- Healthy Volunteers
- Registration Number
- NCT02108015
- Lead Sponsor
- National Institute of Mental Health (NIMH)
- Brief Summary
Objective
Ionotropic glutamate receptors are ligand-gated ion channels responsible for most of the excitatory neurotransmission in the mammalian central nervous system (CNS). Based on pharmacology, they have been grouped into three subtypes-NMDA, AMPA and kainate. In recent years it has become apparent that the receptors do not function alone, but in the company of auxiliary proteins that regulate their activity \[1\]. Some of these have been shown to modulate AMPA receptor trafficking, gating and pharmacology and are classified as transmembrane AMPA receptor regulatory proteins, or TARPs ( \>=-2, \>=-3, \>=-4, \>=-5, \>=-7, and \>=-8). Genetic data indicate a possible role of TARPs in schizophrenia, depression, epilepsy, neuropathic pain, and bipolar disorder \[1\]. In a preclinical collaboration with Eli Lilly, we developed a promising radioligand, 18F-TARP252 to image TARP \>=-8 using positron emission tomography (PET).
This protocol covers three phases:
* Phase 1: kinetic brain imaging to quantify TARP \>=-8 in brain relative to concurrent measurement of the parent radioligand in arterial plasma;
* Phase 2: if 18F-TARP252 is successful in Phase 1, we will estimate the radiation-absorbed doses by performing whole body imaging;
* Phase 3: test-retest analysis of brain binding relative to concurrent measurement of the parent radioligand in arterial plasma.
Study Population
Healthy adult female and male volunteers (n=22, ages 18 - 55) will undergo brain imaging. An additional eight healthy volunteers will undergo whole body dosimetry analysis.
Design
For quantification of TARP \>=-8, 22 healthy controls will have brain PET imaging using 18F-TARP252 and an arterial line. Some of them will have a test-retest scan. Eight additional subjects will have a whole body PET scan for dosimetry. For dosimetry, no arterial line will be used.
Outcome Measures
To assess quantitation of TARP \>=-8 with 18F-TARP252, we will primarily use two outcome measures: the identifiability and time stability of distribution volume calculated with compartmental modeling. In test-retest study, we will calculate the retest variability. We will assess whole-body biodistribution and dosimetry of 18F-TARP252 by calculating doses to organs and effective dose to the body.
- Detailed Description
Objective
Ionotropic glutamate receptors are ligand-gated ion channels responsible for most of the excitatory neurotransmission in the mammalian central nervous system (CNS). Based on pharmacology, they have been grouped into three subtypes-NMDA, AMPA and kainate. In recent years it has become apparent that the receptors do not function alone, but in the company of auxiliary proteins that regulate their activity \[1\]. Some of these have been shown to modulate AMPA receptor trafficking, gating and pharmacology and are classified as transmembrane AMPA receptor regulatory proteins, or TARPs ( \>=-2, \>=-3, \>=-4, \>=-5, \>=-7, and \>=-8). Genetic data indicate a possible role of TARPs in schizophrenia, depression, epilepsy, neuropathic pain, and bipolar disorder \[1\]. In a preclinical collaboration with Eli Lilly, we developed a promising radioligand, 18F-TARP252 to image TARP \>=-8 using positron emission tomography (PET).
This protocol covers three phases:
* Phase 1: kinetic brain imaging to quantify TARP \>=-8 in brain relative to concurrent measurement of the parent radioligand in arterial plasma;
* Phase 2: if 18F-TARP252 is successful in Phase 1, we will estimate the radiation-absorbed doses by performing whole body imaging;
* Phase 3: test-retest analysis of brain binding relative to concurrent measurement of the parent radioligand in arterial plasma.
Study Population
Healthy adult female and male volunteers (n=22, ages 18 - 55) will undergo brain imaging. An additional eight healthy volunteers will undergo whole body dosimetry analysis.
Design
For quantification of TARP \>=-8, 22 healthy controls will have brain PET imaging using 18F-TARP252 and an arterial line. Some of them will have a test-retest scan. Eight additional subjects will have a whole body PET scan for dosimetry. For dosimetry, no arterial line will be used.
Outcome Measures
To assess quantitation of TARP \>=-8 with 18F-TARP252, we will primarily use two outcome measures: the identifiability and time stability of distribution volume calculated with compartmental modeling. In test-retest study, we will calculate the retest variability. We will assess whole-body biodistribution and dosimetry of 18F-TARP252 by calculating doses to organs and effective dose to the body.
Recruitment & Eligibility
- Status
- TERMINATED
- Sex
- All
- Target Recruitment
- 6
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Primary Outcome Measures
Name Time Method Binding of 18F-TARP252 in brain ongoing
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
National Institutes of Health Clinical Center, 9000 Rockville Pike
🇺🇸Bethesda, Maryland, United States