NCT04308954 is a Phase 1 clinical trial of [18F]flumazenil in Fragile X Syndrome (FXS), sponsored by Stanford University.

Who is sponsoring NCT04308954?

NCT04308954 is sponsored by Stanford University.

What drugs are being tested in NCT04308954?

Interventions in NCT04308954: [18F]flumazenil.

What condition does NCT04308954 study?

NCT04308954 studies Fragile X Syndrome (FXS), Idiopathic Intellectual Developmental Disorder (IDD).

Is NCT04308954 still recruiting?

NCT04308954 is currently terminated. Last updated 28 January 2021.

Last reviewed 2021-01-28 · How we verify

NCT04308954

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

Neuroimaging GABA Physiology in Fragile X Syndrome

Terminated Phase 1 Last updated 28 January 2021

What this trial tests

Phase 1 trial testing [18F]flumazenil in Fragile X Syndrome (FXS) in 17 participants. Terminated before completion.

Timeline

1 November 2016

Primary endpoint
6 December 2018

6 December 2018

Quick facts

Lead sponsor	Stanford University
Phase	Phase 1
Status	Terminated
Study type	INTERVENTIONAL
Allocation	non randomized
Design	parallel
Masking	none
Primary purpose	basic science
Enrollment	17
Start date	1 November 2016
Primary completion	6 December 2018
Estimated completion	6 December 2018
Sites	1 location across United States

Drugs / interventions tested

[18F]flumazenil — full drug profile →

Conditions studied

Fragile X Syndrome (FXS) — all drugs for Fragile X Syndrome (FXS) →
Idiopathic Intellectual Developmental Disorder (IDD) — all drugs for Idiopathic Intellectual Developmental Disorder (IDD) →

Sponsor

Stanford University

Who can join

Adults 18 to 30, male only, with Fragile X Syndrome (FXS) or Idiopathic Intellectual Developmental Disorder (IDD). Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The investigators wish to compare the brain distribution of GABA(A) receptors and GABA levels in young adult males with Fragile X Syndrome compared to idiopathic intellectual developmental disorder. The radiopharmaceutical \[18F\]flumazenil has been used to study GABA(A) receptor distribution in other genetic syndromes with autistic features; however, despite overwhelming evidence supporting the importance of the GABAergic system in FXS, no clinical investigation of this system in human FXS has been reported in the literature. Therefore, this study will provide the first in vivo comprehensive examination of the GABAergic system in FXS using hybrid positron emission tomography/ magnetic resonance imaging (PET/MRI).

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

Understanding the function of the GABAergic system and its potential role in rheumatoid arthritis.
Shan Y, Zhao J, Zheng Y, Guo S, et al · · 2023 · cited 18× · PMID 36825000 · DOI 10.3389/fimmu.2023.1114350

Verify or expand the search:

Other recruiting trials for Fragile X Syndrome (FXS)

Currently open trials in the same condition.

NCT07493096 — Intensive Multimodal Neurorehabilitation Targeting Neuroplasticity in Pediatric Neurodevelopmental and Chromosomal Disor · recruiting
NCT06677866 — Group CBT in Adolescents With Fragile X Syndrome and in Adolescents With Autism Spectrum Disorder · NA · recruiting

Other Stanford University trials

Trials by the same sponsor.

NCT05945147 — Ketamine and Midazolam Infusions for CRPS: Feasibility Study · Phase 2 · withdrawn
NCT04225949 — Patients Understanding of PROM Graphs · NA · withdrawn
NCT06273098 — School-Based Bladder Health Intervention · NA · withdrawn
NCT04652635 — Management of Nailbed Injuries · NA · withdrawn
NCT05443503 — Stanford Spine Keeper - Managing Your Low Back Pain · NA · suspended

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT04308954 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Stanford University
Last refreshed: 28 January 2021

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT04308954.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing