An Open-Label Trial of Donepezil in Fragile X Syndrome

Fragile X Syndrome Clinical Trial

Official title:

An Open-Label Trial of Donepezil in Fragile X Syndrome

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00220584
• Other study ID #: 96239
• Status: Completed
• Phase: Phase 1
• First received: September 15, 2005
• Last updated: December 11, 2012
• Start date: July 2005
• Est. completion date: July 2009

Study information

• Verified date: December 2012
• Source: Stanford University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Fragile X syndrome is the most common known inherited cause of neurodevelopmental disability. Functional magnetic resonance imaging (fMRI) studies from our laboratory indicate that specific brain regions using the neurochemical, acetylcholine, show significantly reduced activation during learning. Since donepezil is a medication that enhances acetylcholine function in the brain, the purpose of this study is to determine if donepezil has any beneficial effect on behavior or cognition in subjects with fragile X syndrome.

Description:

Fragile X syndrome is the most common genetically inherited cause of neurodevelopmental disability in humans, affecting approximately 1:2000 to 4000 live births. Affected individuals have significant, long-term problems with learning, and often with behavior as well. The disorder is caused by the presence of a greatly expanded CGG repeat within the FMR1 gene on the long arm of the X chromosome. Abnormal methylation of this repeat, and adjacent areas within the FMR1 gene impedes transcription, ultimately resulting in reduced production of the FMR1 protein (FMRP). This protein is expressed in neurons, with particularly high levels of gene transcription occurring in the nucleus basalis (basal forebrain) and hippocampus. A recent functional imaging study from our group showed girls with fragile X to have greatly reduced levels of brain activation in the basal forebrain and hippocampal activation during a memory task. The nucleus basalis, is a cholinergic nucleus with widespread connections to the neocortex. It is critical to visuospatial attention in rodents and primates and is presumed to play a similar role in humans. The finding of decreased basal forebrain activation in girls with fragile X, considered in light of histological evidence showing high transcription levels of FMR1 in healthy nucleus basalis, suggests the possibility of a functional cholinergic deficit in fragile X syndrome.

Donepezil is an acetylcholinesterase inhibitor which slows the degradation of synaptic acetylcholine thereby increasing its availability. It is approved for the treatment of mild-moderate Alzheimer's disease. It has been studied in several other neurologic disorders--including vascular dementia, Lewy Body dementia, and Down's syndrome (with and without dementia)--where it has shown varying degrees of efficacy but consistently high degrees of safety and tolerability. The goal of the proposed study is to determine if enhancing cholinergic activity with donepezil has beneficial effects on behavior or cognition in subjects with fragile X syndrome.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: July 2009
• Est. primary completion date: July 2009
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 14 Years and older

Eligibility

Inclusion Criteria:1. Confirmed genetic diagnosis of fragile X syndrome

2. Age e 14

3. Verbal IQ e 60

Exclusion Criteria:1. Currently taking any anticholinergic medications, tricyclic antidepressant medications, or diphenhydramine.

2. Presence of cardiac disease or bradycardia (< 60 beats/minute) at initial evaluation.

Study Design

Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Fragile X Syndrome
• Syndrome

Intervention

Drug:
• donepezil
donepezil 5 mg daily for 3 weeks (days 1-21); 10 mg daily for 3 weeks (days 22-42)

Locations

Country	Name	City	State
United States	Stanford University School of Medicine	Stanford	California

Sponsors (1)

Lead Sponsor	Collaborator
Stanford University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Scores on learning tests at baseline		baseline, day 21, day 42	No
Primary	score on test of attention		baseline, day 21, day 42	No
Primary	score on measures of behavior		baseline, day 21, day 42	No
Primary	scores on learning tests		baseline, day 21, day 42	No
Primary	scores on working memory tests		baseline, day 21, day 42	No