First-in-Human Evaluation of an Astrocytic Glutamate Transporter (EAAT2) PET Tracer in Dementia

NCT ID: NCT05374278

Last Updated: 2025-04-17

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

RECRUITING

Clinical Phase

PHASE1/PHASE2

Total Enrollment

102 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-11-02

Study Completion Date

2027-05-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

This is a first in human study that will assess the safety and diagnostic performance of \[18F\]RP-115 (fluorine-18 labeled RP115), a positron emission tomography (PET) agent. This agent has the potential to identify the early changes that occur in the brains of patients with Alzheimer's disease (AD) and frontotemporal dementia (FTD).

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

AD and FTD are the two leading causes of dementia with tremendous impact on patients and their families. Early diagnosis of both AD and FTD is essential to increase patients' quality of life, identify and treat reversible causes, and enhance the development and effectiveness of treatments. However, no single diagnostic agent is currently available for either AD or FTD; instead, clinicians must rely on the patient's history and cognitive testing which often leads to delayed or incorrect diagnosis. Importantly AD and FTD have distinct regional patterns of neuronal loss and dysfunction in the brain; an agent that could detect these regionally specific changes early in the course of the disease process could revolutionize diagnosis and treatment development for these conditions.

This study aims to develop a novel radiotracer to fill this unmet need. The excitatory amino acid transporter 2 (EAAT2) is the main transporter for glutamate in the brain and has been shown to be downregulated in the context of AD and other neurodegenerative conditions. EAAT2 is responsible for over 90% of glutamate uptake in the brain where it is primarily located on astrocytes and plays a key role in maintaining the homeostasis of the tripartite synapse. The goal of this study is to test the EAAT2 targeted positron emitting agent, \[18F\]RP-115, to evaluate early changes in astrocytes in healthy controls versus patients with AD and FTD by quantitative PET imaging of EAAT2. We have preclinical data that demonstrates that this agent is a good predictor of EAAT2 levels in animal models, hence, can potentially detect early signs of neurodegeneration. We now wish to test this agent in humans.

In summary, the primary objective of this study is to demonstrate human safety and measure the biodistribution of \[18F\]RP-115 in healthy controls as well as in age-matched patients with AD and FTD.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Alzheimer Disease Frontotemporal Dementia Dementia

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

DIAGNOSTIC

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Cohort 1 - dosimetry of [18F]RP-115 in healthy volunteers

Establish \[18F\]RP-115 safety in the clinic with male and female PET imaging.

Group Type EXPERIMENTAL

[18F]RP-115 PET/MRI or PET/CT and MRI

Intervention Type DRUG

An I.V. bolus injection of up to 10 millicurie (mCi) \[18F\]RP-115 will be administered, followed by a PET/MRI scan or by a combination of PET/CT and MRI

Cohort 2B - [18F]RP-115 in patients with AD

Comparison of \[18F\]RP-115 PET binding between AD patients and age-matched cognitively normal controls and between AD and FTD

Group Type EXPERIMENTAL

[18F]RP-115 PET/MRI or PET/CT and MRI

Intervention Type DRUG

An I.V. bolus injection of up to 10 millicurie (mCi) \[18F\]RP-115 will be administered, followed by a PET/MRI scan or by a combination of PET/CT and MRI

Cohort 2C - [18F]RP-115 in patients with FTD

Comparison of \[18F\]RP-115 PET binding between AD patients and age-matched cognitively normal controls and between AD and FTD

Group Type EXPERIMENTAL

[18F]RP-115 PET/MRI or PET/CT and MRI

Intervention Type DRUG

An I.V. bolus injection of up to 10 millicurie (mCi) \[18F\]RP-115 will be administered, followed by a PET/MRI scan or by a combination of PET/CT and MRI

Cohort 2A - [18F]RP-115 in age-matched controls

Comparison of \[18F\]RP-115 PET binding between AD patients and age-matched cognitively normal controls and between AD and FTD

Group Type EXPERIMENTAL

[18F]RP-115 PET/MRI or PET/CT and MRI

Intervention Type DRUG

An I.V. bolus injection of up to 10 millicurie (mCi) \[18F\]RP-115 will be administered, followed by a PET/MRI scan or by a combination of PET/CT and MRI

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

[18F]RP-115 PET/MRI or PET/CT and MRI

An I.V. bolus injection of up to 10 millicurie (mCi) \[18F\]RP-115 will be administered, followed by a PET/MRI scan or by a combination of PET/CT and MRI

Intervention Type DRUG

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

1. Age 40-75
2. Age-suitable BMI
3. Ability to provide written informed consent and willingly comply with protocol requirements or has a legal authorized representative/guardian who provides surrogate informed consent.
4. No apparent physical disorder.
5. Radial, ulnar, or brachial artery suitable for catheterization.
6. Non-smoker, and not taking OTC nicotine cessation - to limit peripheral metabolism events.
7. Devoid of CNS prescription drugs for three weeks - to limit peripheral metabolism events.

For Cohort 2B and 2C:
8. Must have a study partner (informant) who spends a minimum average of 5 hours per week with the participant (e.g. family member, significant other, friend, caregiver), is generally aware of the participant's daily activities, can provide information about the participant's cognitive and functional performance, and will accompany the participant in all study procedure.
9. Recent (within 6 mo.) MME clinical scores.

Exclusion Criteria

1. Unable to provide written informed consent and unwilling to comply with protocol requirements, or does not have a legal authorized representative/guardian who can provide surrogate informed consent.
2. Inadequate arterial access.
3. Receipt of radioisotope \< 5 half-lives within \[18F\]RP-115 imaging- as to not confound any scans with radiation background for previous scanning, and unsuitable organ dosimetry thresholds from previous (\> two weeks) PET scans.
4. The performed \[18F\]RP-115 scan(s) must not represent \> 3 PET studies total within one year.
5. Contra-indication to magnetic resonance, including permanent pacemaker, implantable metallic device, etc.; or severe claustrophobia.
6. Participants who are pregnant (female patients of childbearing age will be tested prior to injection of tracer- positive test excludes from the study)
7. Participants who are breast-feeding.
8. Have a medical condition or other circumstances that in the opinion of the project physicians would significantly decrease chances of obtaining reliable data, achieving the study objective or completing the study.
Minimum Eligible Age

40 Years

Maximum Eligible Age

75 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Rio pharmaceuticals Inc.

UNKNOWN

Sponsor Role collaborator

David Wilson

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

David Wilson

Professor, Radiology

Responsibility Role SPONSOR_INVESTIGATOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

David Wilson, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

University of California, San Francisco

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

China Basin, UCSF

San Francisco, California, United States

Site Status RECRUITING

Countries

Review the countries where the study has at least one active or historical site.

United States

Central Contacts

Reach out to these primary contacts for questions about participation or study logistics.

David Wilson, MD, PhD

Role: CONTACT

415-514-6229

Henry Vanbrocklin, PhD

Role: CONTACT

415-353-4569

Facility Contacts

Find local site contact details for specific facilities participating in the trial.

David Wilson, MD, PhD

Role: primary

References

Explore related publications, articles, or registry entries linked to this study.

Jack CR Jr, Bennett DA, Blennow K, Carrillo MC, Dunn B, Haeberlein SB, Holtzman DM, Jagust W, Jessen F, Karlawish J, Liu E, Molinuevo JL, Montine T, Phelps C, Rankin KP, Rowe CC, Scheltens P, Siemers E, Snyder HM, Sperling R; Contributors. NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimers Dement. 2018 Apr;14(4):535-562. doi: 10.1016/j.jalz.2018.02.018.

Reference Type BACKGROUND
PMID: 29653606 (View on PubMed)

Boche D, Gerhard A, Rodriguez-Vieitez E; MINC Faculty. Prospects and challenges of imaging neuroinflammation beyond TSPO in Alzheimer's disease. Eur J Nucl Med Mol Imaging. 2019 Dec;46(13):2831-2847. doi: 10.1007/s00259-019-04462-w. Epub 2019 Aug 8.

Reference Type BACKGROUND
PMID: 31396666 (View on PubMed)

Innis RB, Cunningham VJ, Delforge J, Fujita M, Gjedde A, Gunn RN, Holden J, Houle S, Huang SC, Ichise M, Iida H, Ito H, Kimura Y, Koeppe RA, Knudsen GM, Knuuti J, Lammertsma AA, Laruelle M, Logan J, Maguire RP, Mintun MA, Morris ED, Parsey R, Price JC, Slifstein M, Sossi V, Suhara T, Votaw JR, Wong DF, Carson RE. Consensus nomenclature for in vivo imaging of reversibly binding radioligands. J Cereb Blood Flow Metab. 2007 Sep;27(9):1533-9. doi: 10.1038/sj.jcbfm.9600493. Epub 2007 May 9.

Reference Type BACKGROUND
PMID: 17519979 (View on PubMed)

Rice L, Bisdas S. The diagnostic value of FDG and amyloid PET in Alzheimer's disease-A systematic review. Eur J Radiol. 2017 Sep;94:16-24. doi: 10.1016/j.ejrad.2017.07.014. Epub 2017 Jul 20.

Reference Type BACKGROUND
PMID: 28941755 (View on PubMed)

Rodriguez-Vieitez E, Carter SF, Chiotis K, Saint-Aubert L, Leuzy A, Scholl M, Almkvist O, Wall A, Langstrom B, Nordberg A. Comparison of Early-Phase 11C-Deuterium-l-Deprenyl and 11C-Pittsburgh Compound B PET for Assessing Brain Perfusion in Alzheimer Disease. J Nucl Med. 2016 Jul;57(7):1071-7. doi: 10.2967/jnumed.115.168732. Epub 2016 Feb 16.

Reference Type BACKGROUND
PMID: 26912447 (View on PubMed)

Arakawa R, Stenkrona P, Takano A, Nag S, Maior RS, Halldin C. Test-retest reproducibility of [11C]-L-deprenyl-D2 binding to MAO-B in the human brain. EJNMMI Res. 2017 Dec;7(1):54. doi: 10.1186/s13550-017-0301-4. Epub 2017 Jun 20.

Reference Type BACKGROUND
PMID: 28634836 (View on PubMed)

Cowburn R, Hardy J, Roberts P, Briggs R. Presynaptic and postsynaptic glutamatergic function in Alzheimer's disease. Neurosci Lett. 1988 Mar 21;86(1):109-13. doi: 10.1016/0304-3940(88)90192-9.

Reference Type BACKGROUND
PMID: 2896322 (View on PubMed)

Scott HL, Tannenberg AE, Dodd PR. Variant forms of neuronal glutamate transporter sites in Alzheimer's disease cerebral cortex. J Neurochem. 1995 May;64(5):2193-202. doi: 10.1046/j.1471-4159.1995.64052193.x.

Reference Type BACKGROUND
PMID: 7722505 (View on PubMed)

Hoshi A, Tsunoda A, Yamamoto T, Tada M, Kakita A, Ugawa Y. Altered expression of glutamate transporter-1 and water channel protein aquaporin-4 in human temporal cortex with Alzheimer's disease. Neuropathol Appl Neurobiol. 2018 Oct;44(6):628-638. doi: 10.1111/nan.12475. Epub 2018 Mar 4.

Reference Type BACKGROUND
PMID: 29405337 (View on PubMed)

Li S, Mallory M, Alford M, Tanaka S, Masliah E. Glutamate transporter alterations in Alzheimer disease are possibly associated with abnormal APP expression. J Neuropathol Exp Neurol. 1997 Aug;56(8):901-11. doi: 10.1097/00005072-199708000-00008.

Reference Type BACKGROUND
PMID: 9258260 (View on PubMed)

Pasqualetti G, Brooks DJ, Edison P. The role of neuroinflammation in dementias. Curr Neurol Neurosci Rep. 2015 Apr;15(4):17. doi: 10.1007/s11910-015-0531-7.

Reference Type BACKGROUND
PMID: 25716012 (View on PubMed)

Miller ZA, Sturm VE, Camsari GB, Karydas A, Yokoyama JS, Grinberg LT, Boxer AL, Rosen HJ, Rankin KP, Gorno-Tempini ML, Coppola G, Geschwind DH, Rademakers R, Seeley WW, Graff-Radford NR, Miller BL. Increased prevalence of autoimmune disease within C9 and FTD/MND cohorts: Completing the picture. Neurol Neuroimmunol Neuroinflamm. 2016 Oct 28;3(6):e301. doi: 10.1212/NXI.0000000000000301. eCollection 2016 Dec.

Reference Type BACKGROUND
PMID: 27844039 (View on PubMed)

Arnold SE, Han LY, Clark CM, Grossman M, Trojanowski JQ. Quantitative neurohistological features of frontotemporal degeneration. Neurobiol Aging. 2000 Nov-Dec;21(6):913-9. doi: 10.1016/s0197-4580(00)00173-1.

Reference Type BACKGROUND
PMID: 11124442 (View on PubMed)

Lui H, Zhang J, Makinson SR, Cahill MK, Kelley KW, Huang HY, Shang Y, Oldham MC, Martens LH, Gao F, Coppola G, Sloan SA, Hsieh CL, Kim CC, Bigio EH, Weintraub S, Mesulam MM, Rademakers R, Mackenzie IR, Seeley WW, Karydas A, Miller BL, Borroni B, Ghidoni R, Farese RV Jr, Paz JT, Barres BA, Huang EJ. Progranulin Deficiency Promotes Circuit-Specific Synaptic Pruning by Microglia via Complement Activation. Cell. 2016 May 5;165(4):921-35. doi: 10.1016/j.cell.2016.04.001. Epub 2016 Apr 21.

Reference Type BACKGROUND
PMID: 27114033 (View on PubMed)

Yin F, Banerjee R, Thomas B, Zhou P, Qian L, Jia T, Ma X, Ma Y, Iadecola C, Beal MF, Nathan C, Ding A. Exaggerated inflammation, impaired host defense, and neuropathology in progranulin-deficient mice. J Exp Med. 2010 Jan 18;207(1):117-28. doi: 10.1084/jem.20091568. Epub 2009 Dec 21.

Reference Type BACKGROUND
PMID: 20026663 (View on PubMed)

Provided Documents

Download supplemental materials such as informed consent forms, study protocols, or participant manuals.

Document Type: Informed Consent Form

View Document

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

13180640

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

Tau PET Imaging in Atypical Dementias
NCT03283449 COMPLETED PHASE1
Assess Fibrin in Brains With AD/ADRD
NCT05336695 RECRUITING PHASE1/PHASE2
Neuroinflammation Imaging in AD
NCT04274998 RECRUITING EARLY_PHASE1
Florbetaben PET Imaging in PPA
NCT04720001 COMPLETED
PET Tau - Neurodegenerative Disease Imaging
NCT03143374 RECRUITING PHASE2/PHASE3