Alzheimer DiseaseNCT05582200
Selective PET Imaging of Astrocytes and Microglia in Alzheimer's Disease
An observational study of Alzheimer Disease and Healthy, run by The Methodist Hospital Research Institute at 1 site in United States.
Trial summary
Inflammation occurs in many brain diseases including Alzheimer's disease. In Alzheimer's disease, an abnormal protein called amyloid starts accumulating decades before the start of forgetfulness. Read more about this study
- Who is it for?
- Ages 18 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- Alzheimer Disease, Healthy
- What is being tested?
- Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-B
- How many people
- 71 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Jan 2023to 31 Oct 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Healthy volunteers and patients with Alzheimer's disease
Who may be able to join
- Individuals of either sex, 50-90 years of age.
- Meeting research criteria for AD (McKhann, Knopman et al. 2011).
- With a CDR (Morris 1993) score of 1-3.
- Fluent in English or Spanish.
- Have sufficient communication and comprehension ability to consent to the performance of the study or have a legally authorized representative.
- Individuals of 18-90 years of age.
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- Negative amyloid accumulation determined by PET (only for the comparison with AD).
- Fluent in English.
- Have enough communication and comprehension ability to consent to the performance of the study.
Who cannot join
- Inability to undergo MRI or PET for any reason, including severe claustrophobia.
- History of large stroke or brain trauma, multiple sclerosis or other brain disorder that, in the judgment of the PI may confound the study.
- Pregnancy. In women in whom the possibility of pregnancy cannot be excluded, a pregnancy test must be performed on site the morning of any PET visit and a negative result together with a physician interview are required prior to the administration or any radiopharmaceutical.
- Research radiation exposure greater than 50 mSv effective dose within 12 months including radiation exposure from this study.
- Healthy volunteers:
- Inability to undergo MRI or PET for any reason, including severe claustrophobia.
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- Brain disorder, other than idiopathic headache.
- Current primary Axis I or II psychiatric disorder.
- Current use of psychotropic or anti-epileptic medication.
- Substance abuse during the past two years.
- Active cancer, metabolic encephalopathy, infection, cardiovascular disease.
- Active hematological, renal, pulmonary, endocrine or hepatic disorders, except for treated thyroid disease.
- Pregnancy. In women in whom the possibility of pregnancy cannot be excluded, a pregnancy test must be performed on site the morning of any PET visit and a negative result together with a physician interview are required prior to the administration or any radiopharmaceutical
- Research radiation exposure greater than 50 mSv effective dose within 12 months including radiation exposure from this study.
- Only for the subjects undergoing the blocked scan with selegiline: known contraindications to selegiline, including hypersensitivity to the drug and use of opioids, such as meperidine and some antidepressants such as bupropion.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Houston Methodist Research Institute
Houston, Texas, 77030
Joseph C. Masdeu, MD, PhD, 713-441-1150, jcmasdeu@houstonmethodist.org
Belen Pascual, PhD, 7134411150, bpascual@houstonmethodist.org
About this study
Inflammation occurs in many brain diseases including Alzheimer's disease. In Alzheimer's disease, an abnormal protein called amyloid starts accumulating decades before the start of forgetfulness. However, scientists have reported that inflammation but not amyloid is linked to forgetfulness and the topography of brain inflammation and tau buildup are closely correlated in patients with mild cognitive impairment due to Alzheimer's disease. New medications are under development to help healing and prevent permanent damage in the brain. To see if inflammation is improving or getting worse with these medications, investigators can watch inside of the brain using a special camera called positron emission tomography (PET). It is currently possible to watch inflammation in the brain by taking pictures of a molecule called translocator protein (TSPO). But the problem is that by imaging TSPO, investigators can catch changes in more than one kind of cells. The information is not specific to each cell type. Such vague information is not completely useful to monitor the effect of new medications for inflammation. This proposal attempts to develop a novel method to capture changes in each of two major players in inflammation, microglia and astrocytes. To do so, investigators will take selective pictures of one cell type by using a novel imaging agent for PET. Investigators will also take PET pictures of TSPO. Investigators will process these two kinds of PET pictures using advanced mathematical methods and extract specific information on microglia and astrocytes. Our novel method will be useful to monitor new therapies to treat inflammation in the brain.
Read the detailed description
Inflammation in brain plays critical roles in disease progress and symptom development in a number of brain disorders such as Alzheimer's disease (AD), traumatic brain injury, major depressive disorder, epilepsy, and schizophrenia. Neuroinflammation has been imaged using positron emission tomography (PET) by using translocator protein (TSPO) as the marker. Although TSPO PET studies have provided insight to understand the pathology, some results are difficult to interpret. TSPO imaging has a major limitation of not being selective to one type of glia; it is expressed by both microglia and astrocyte. The current study attempts to overcome this limitation. Monoamine oxidase type-B (MAO-B) is highly expressed by astrocyte and serotonin (5-HT)-releasing neurons but not by microglia. PET studies using a prototype tracer 11C-L-deprenyl detects astrogliosis in mild cognitive impairment (MCI) but this tracer has low levels of specific binding. Preliminary results show that a novel tracer 18F-SMBT-1 developed by Dr. Okamura and his colleagues has several times greater levels of specific binding. The Aims of the current study are to 1) estimate radiation-absorbed doses in 8 healthy people, 2) measure ratios of specific-to-nondisplaceable binding by performing brain scans with and without binding blockade in 5 patients with Alzheimer's disease, 3) measure reproducibility of measuring 18F-SMBT-1 in 8 healthy people, 4) compare MAO-B levels between healthy controls (n = 25) and patients with AD (n = 25), and 5) from 11C-ER176 for TSPO and 18F-SMBT-1, extract cell type specific information for microglia and astrocytes and investigate changes in each cell type In AD.
- Conditions
- Alzheimer Disease, Healthy
- Being tested
- Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-B
- Medical subject headings
- Alzheimer Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-BDrug
Participants will receive PET with 11C-ER176 to measure microglia AND astrocytes and PET with 18F-SMBT1 to measure astrocytes.
| Study group | Role | What they receive |
|---|---|---|
| Healthy subjects | Healthy subjects Receives: Drug: Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-B | |
| Patients with Alzheimer's disease | Patients with Alzheimer's disease Receives: Drug: Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-B |
What is being measured
The primary outcome is the main question the study is designed to answer.
The level of monoamine oxidase-B
Binding of PET tracer [F-18]SMBT-1 to monoamine oxidase-B
Measured: At the time of the PET scan
The level of translocator protein
Binding of PET tracer [C-11]ER176 to translocator protein
Measured: At the time of the PET scan
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Oct 2022
- Study start20 Jan 2023
- Primary completion31 Oct 2027 (estimated)
- Study completion31 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Alzheimer DiseaseStudies of the same condition, open and under way.
- More trials run by The Methodist Hospital Research InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Other
- Time perspective
- Other
- Enrolment
- 71 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Methodist Hospital Research Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05582200
- Sponsor's protocol ID
- PRO00030631
- Status last verified
- Mar 2026
- First submitted
- 7 Oct 2022
- Last updated
- 6 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: It is complex to share IPD in our regulatory environment.
Study at a glance
From the registry record, last updated by the sponsor on 6 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Selective PET Imaging of Astrocytes and Microglia in Alzheimer's Disease
- ClinicalTrials.gov ID
- NCT05582200
- Acronym / sponsor ID
- PRO00030631
- Conditions
- Alzheimer Disease, Healthy
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 71 participants (estimated)
- Lead sponsor
- The Methodist Hospital Research InstituteUniversity, hospital or other
- Study start
- 20 Jan 2023 (actual)
- Primary completion
- 31 Oct 2027 (estimated)
- Study completion
- 31 Oct 2028 (estimated)
- First posted
- 17 Oct 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Inflammation occurs in many brain diseases including Alzheimer's disease. In Alzheimer's disease, an abnormal protein called amyloid starts accumulating decades before the start of forgetfulness. However, scientists have reported that inflammation but not amyloid is linked to forgetfulness and the topography of brain inflammation and tau buildup are closely correlated in patients with mild cognitive impairment due to Alzheimer's disease. New medications are under development to help healing and prevent permanent damage in the brain. To see if inflammation is improving or getting worse with these medications, investigators can watch inside of the brain using a special camera called positron emission tomography (PET). It is currently possible to watch inflammation in the brain by taking pictures of a molecule called translocator protein (TSPO). But the problem is that by imaging TSPO, investigators can catch changes in more than one kind of cells. The information is not specific to each cell type. Such vague information is not completely useful to monitor the effect of new medications for inflammation. This proposal attempts to develop a novel method to capture changes in each of two major players in inflammation, microglia and astrocytes. To do so, investigators will take selective pictures of one cell type by using a novel imaging agent for PET. Investigators will also take PET pictures of TSPO. Investigators will process these two kinds of PET pictures using advanced mathematical methods and extract specific information on microglia and astrocytes. Our novel method will be useful to monitor new therapies to treat inflammation in the brain.
Detailed description
Inflammation in brain plays critical roles in disease progress and symptom development in a number of brain disorders such as Alzheimer's disease (AD), traumatic brain injury, major depressive disorder, epilepsy, and schizophrenia. Neuroinflammation has been imaged using positron emission tomography (PET) by using translocator protein (TSPO) as the marker. Although TSPO PET studies have provided insight to understand the pathology, some results are difficult to interpret. TSPO imaging has a major limitation of not being selective to one type of glia; it is expressed by both microglia and astrocyte. The current study attempts to overcome this limitation. Monoamine oxidase type-B (MAO-B) is highly expressed by astrocyte and serotonin (5-HT)-releasing neurons but not by microglia. PET studies using a prototype tracer 11C-L-deprenyl detects astrogliosis in mild cognitive impairment (MCI) but this tracer has low levels of specific binding. Preliminary results show that a novel tracer 18F-SMBT-1 developed by Dr. Okamura and his colleagues has several times greater levels of specific binding. The Aims of the current study are to 1) estimate radiation-absorbed doses in 8 healthy people, 2) measure ratios of specific-to-nondisplaceable binding by performing brain scans with and without binding blockade in 5 patients with Alzheimer's disease, 3) measure reproducibility of measuring 18F-SMBT-1 in 8 healthy people, 4) compare MAO-B levels between healthy controls (n = 25) and patients with AD (n = 25), and 5) from 11C-ER176 for TSPO and 18F-SMBT-1, extract cell type specific information for microglia and astrocytes and investigate changes in each cell type In AD.
Study design
- Observational model
- Other
- Time perspective
- Other
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Healthy subjects | – | Drug: Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-BHealthy subjects |
| Patients with Alzheimer's disease | – | Drug: Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-BPatients with Alzheimer's disease |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Healthy volunteers and patients with Alzheimer's disease
Key inclusion criteria (9 listed)
- Individuals of either sex, 50-90 years of age.
- Meeting research criteria for AD (McKhann, Knopman et al. 2011).
- With a CDR (Morris 1993) score of 1-3.
- Fluent in English or Spanish.
- Have sufficient communication and comprehension ability to consent to the performance of the study or have a legally authorized representative.
Key exclusion criteria (15 listed)
- Inability to undergo MRI or PET for any reason, including severe claustrophobia.
- History of large stroke or brain trauma, multiple sclerosis or other brain disorder that, in the judgment of the PI may confound the study.
- Pregnancy. In women in whom the possibility of pregnancy cannot be excluded, a pregnancy test must be performed on site the morning of any PET visit and a negative result together with a physician interview are required prior to the administration or any radiopharmaceutical.
- Research radiation exposure greater than 50 mSv effective dose within 12 months including radiation exposure from this study.
- Inability to undergo MRI or PET for any reason, including severe claustrophobia.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Positron Emission Tomography (PET) using 11C-ER176 for TSPO and 18F-SMBT1 for MAO-BParticipants will receive PET with 11C-ER176 to measure microglia AND astrocytes and PET with 18F-SMBT1 to measure astrocytes. | Drug | Healthy subjects, Patients with Alzheimer's disease |
Primary outcome
The level of monoamine oxidase-B
Time frame: At the time of the PET scan
Binding of PET tracer [F-18]SMBT-1 to monoamine oxidase-B
The level of translocator protein
Time frame: At the time of the PET scan
Binding of PET tracer [C-11]ER176 to translocator protein
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Apr 2026.
- Individual participant dataSharing planned: No. It is complex to share IPD in our regulatory environment.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Alzheimer Disease and Healthy, run by The Methodist Hospital Research Institute 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 9 inclusion and 15 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: looking for participants now, as of the sponsor's last update on 6 Apr 2026. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Joseph C. Masdeu, MD, PhD (7134411150, jcmasdeu@houstonmethodist.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The level of monoamine oxidase-B (time frame: At the time of the PET scan). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 6 Apr 2026.