Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT06087757

Clemastine Treatment in Individuals With Williams Syndrome

This study explores the neurobiological etiology of Williams syndrome and potential therapeutic targets for associated social, motor, and cognitive abnormalities. The main translational objective will be to test the effectiveness of Clemasntine on neurocognitive and other associated abnormalities in individuals with Williams syndrome.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Williams Syndrome Aortic Stenosis, Supravalvular Aortic Valve Disease Aortic Valve Stenosis Cardiovascular Diseases Chromosome Disorders Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Heart Diseases Heart Valve Diseases Intellectual Disability Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations

Age range

6 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Child and Adolescent Psychiatry Unit, Sheba Medical Center, Ramat Gan, Israel

Loading trial locations.

About this study

The overarching aim of the research proposed is to examine the safty of Clemastine use for individuals with Williams syndrome. Further, we wish to examine the relationship between Clemastine treatment and cognitive, motor and behavioral deficits in individuals with Williams syndrome. This study is an open-label study with a blinded randomize withdrawal. Each participant will go through a baseline evaluation (see study outcomes) and will be treated with the FDA approved drug Clemastine, in an age dependent dose (dosage table below). After a substantial improvement will be noticed, the participants will be divided into 2 groups, in a randomized, double-blind, placebo-control study design.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Individuals with Williams syndrome, which has been confirmed by genetic testing.
  • Ages 6-30.
  • Normal values in safety variables (e.g. Normal ECG 120-129/80-84).
  • No change in psychotropic medications and dosage during the last 4 weeks.
  • During the study, no pharmacological change that may impact the study (e.g. ADHD
  • medications).

Exclusion criteria

  • Individuals with another genetic disorder besides Williams syndrome.
  • Individuals with Williams syndrome, younger than 6 or older than 30 years old.
  • Significant change in normal values in safety variables (e.g. high or low ECG).
  • Change in medications and dosage during the last 4 weeks prior the beginning and
  • during the study.
  • Pregnancy.
  • Using addictive substances such as alcohol.

Treatment and study plan

Open Label Clemastine with a blinded randomize withdrawal

Drug

Clemastine will be given in doses as the maximum dose recommended for allergy condition. Age 6-12 years 4.02 mg/day, age 12-30 years 8.04 mg/day.

Primary outcomes

  1. Neurocognitive measures

    Time frame: December 2024

    Wechsler Intelligence Scale: The standard age-appropriate Wechsler scale. Wechsler Intelligence Scale for Children, 4th edition(Wechsler 1991, Wechsler 2003) for subjects 17 years and younger and the Wechsler Adult Intelligence Scale, 3rd edition (WAIS III)(Wechsler 1997) for subjects older than 17 years.

    NIH ToolBox (NIHTB): the NIHTB is a computerized neurocognitive battery developed by NIH that was designed to include measures of cognitive flexibility and inhibitory control, as well as a measure of working memory. http://www.healthmeasures.net/explore-measurement-systems/nih-toolbox/

Secondary outcomes

  1. Motor and Neurological assessment. Motor and Neurological assessment. Motor and Neurological assessment. Motor and neurolocgial measures

    Time frame: December 2024

    The Beery-Buktenica Developmental Test of Visual-Motor Integration

    GAITRite walkway: GAITRite is a sensitive walkway measuring temporal and spatial parameters.

    Psychiatric evaluation: a semi-structured interview for neuropsychiatric diagnoses with the Schedule for Affective Disorders and Schizophrenia for School-Aged Children.

    The Child Behavior Checklist: measures behavioral/emotional problems and competencies.

    Attention Deficit Hyperactivity Disorder Rating Scale.

    The Screen for Child Anxiety-Related Emotional Disorders.

    The Social Responsiveness Scale-Second Edition.

    Adaptive Behavior Assessment System-2nd Edition.

Sponsors and collaborators

Lead sponsor

Sheba Medical Center

Other Gov

Collaborators

  • Tel Aviv University

Registry information

Official study title

Clemastine Treatment in Individuals With Williams Syndrome- a Double-blind Placebo Control to Assess the Safety and Efficacy

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Oct 18, 2023
Registry last updated
Mar 6, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.