Effects of Kuvan on Brain and Cognition in Individuals With Phenylketonuria

This study is enrolling participants by invitation only.
Sponsor:
Collaborators:
BioMarin Pharmaceutical
University of Missouri-Columbia
Information provided by:
Washington University School of Medicine
ClinicalTrials.gov Identifier:
NCT00730080
First received: August 1, 2008
Last updated: NA
Last verified: August 2008
History: No changes posted
  Purpose

Investigators at Washington University will examine the effects of sapropterin (Kuvan) on brain and cognition in individuals with phenylketonuria (PKU) using neuropsychological and neuroimaging procedures. Sapropterin is a medication developed by BioMarin Pharmaceutical, Inc. that is approved by the FDA for treatment of patients with PKU to reduce phenylalanine (Phe) levels. Patients beginning treatment with sapropterin as standard clinical care will be enrolled in the study. As a first step, patients with PKU will receive baseline neuropsychological and neuroimaging evaluations 1 day prior to beginning treatment with sapropterin. Screening for response to sapropterin will occur over 4 weeks. At the end of 4 weeks, response to sapropterin will be reviewed, and patients with a reduction of ≥ 20% in blood Phe will continue in the study. Follow-up neuropsychological and neuroimaging evaluations will occur at the end of 6 months of treatment with sapropterin.

The focus of neuropsychological testing will be executive abilities, as these abilities are particularly susceptible to disruption in individuals with PKU. We hypothesize that improvements in these abilities will occur following treatment with sapropterin. For neuroimaging assessments, structural magnetic resonance imaging (MRI) will permit evaluation of changes in the structure and volume of the gray and white matter of the brain, whereas diffusion tensor imaging (DTI)will permit evaluation of the functional integrity of the white matter of the brain.


Condition Intervention
Phenylketonuria
Drug: Sapropterin (Kuvan)

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Effects of Sapropterin on Brain and Cognition in Individuals With Phenylketonuria

Resource links provided by NLM:


Further study details as provided by Washington University School of Medicine:

Primary Outcome Measures:
  • Wechsler Abbreviated Scale of Intelligence [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • diffusion tensor imaging of the brain [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • working memory n-back task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • working memory recognition span task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • strategic processing list learning task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • strategic processing verbal fluency task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • inhibitory control go/no-go task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • inhibitory control stimulus-response compatibility task [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]
  • structural magnetic resonance imaging of the brain [ Time Frame: baseline & 6 month follow-up ] [ Designated as safety issue: No ]

Estimated Enrollment: 35
Study Start Date: July 2008
Estimated Study Completion Date: July 2009
Estimated Primary Completion Date: July 2009 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Phenylketonuria
Individuals with phenylketonuria (PKU) who are beginning treatment with sapropterin.
Drug: Sapropterin (Kuvan)
20mg/kg/day taken once daily or as otherwise prescribed by physician as standard care.
Other Name: Kuvan
Control
Healthy individuals without phenylketonuria (PKU).

Detailed Description:

Investigators at Washington University will examine the effects of sapropterin (Kuvan) on brain and cognition in individuals with phenylketonuria (PKU) using neuropsychological and neuroimaging procedures. Sapropterin is a medication developed by BioMarin Pharmaceutical, Inc. that was recently approved by the FDA for treatment of patients with PKU to reduce phenylalanine (Phe) levels. Patients beginning treatment with sapropterin as standard clinical care will be enrolled. As a first step, 25 patients with PKU who are ≥ 6 years of age will receive baseline neuropsychological and neuroimaging evaluations 1 day prior to beginning their treatment with sapropterin. Screening for response to sapropterin (20mg/kg/day) will then occur over 4 weeks as standard care for enrolled patients. At the end of 4 weeks, response to sapropterin will be reviewed. Fifteen patients with a reduction of ≥ 20% in blood phenylalanine (Phe) will continue in the study and receive follow-up neuropsychological and neuroimaging evaluations at the end of 6 months of treatment with sapropterin.

A matched control group of 10 healthy individuals without PKU will receive baseline neuropsychological and neuroimaging evaluations. The 10 control participants will receive follow-up neuropsychological (but not neuroimaging) evaluations for comparison purposes and to control for possible practice effects in repeated neuropsychological testing.

The focus of neuropsychological testing will be executive abilities, as these abilities are particularly susceptible to disruption in individuals with PKU. Specifically, the focus of neuropsychological assessment will be working memory, strategic processing, and inhibitory control, as our research group has shown that each of these executive abilities is impaired in individuals with PKU. (White, D. 2001 Neuropsychol.)(White, D. 2002 J. Int. Neuropsychol. Soc.)(Christ, S. 2006 Dev. Neuropsychol.) We hypothesize that improvements in these abilities will occur following treatment with sapropterin.

For neuroimaging assessments, both structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI; mean diffusivity and anisotropy) will be used. Structural MRI will permit evaluation of changes in the structure and volume of the gray and white matter of the brain. DTI will permit evaluation of the functional integrity of the white matter of the brain. Brain abnormalities have been noted in individuals with PKU, and using DTI our research group recently identified abnormalities in the integrity of white matter in early and continuously treated individuals with PKU.

The primary objectives of the proposed study are two-fold. First, we will determine if cognition (particularly executive abilities) improves in patients with PKU who have been treated with sapropterin for a period of 6 months. Second, we will determine if the structure and functional integrity of the brain improves in patients with PKU who have been treated with sapropterin for a period of 6 months. In addition, the interrelationships between changes in cognition and brain will be examined.

  Eligibility

Ages Eligible for Study:   6 Years to 50 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Primary care clinic for phenylketonuria. St. Louis community for control.

Criteria

Inclusion Criteria:

  • Willing and able to provide informed consent or assent.
  • Willing and able to comply with study procedures.
  • Greater than or equal to 6 years of age.
  • For phenylketonuria,intention of physician to prescribe sapropoterin.
  • For phenylketonuria,phenylalanine level greater than or equal to 450μmol/L.
  • For phenylketonuria, negative pregnancy test if of childbearing potential.
  • For phenylketonuria, willing to use contraception if sexually active.

Exclusion Criteria:

  • Pregnant, breastfeeding, or planning to become pregnant during study.
  • Use of investigational product less than 30 days prior to or during study.
  • Concurrent condition that could interfere with participation or safety.
  • Any condition creating high risk of poor compliance with study.
  • Perceived to be unreliable or unavailable for study.
  • Use of L-Dopa, methotrexate, or other drugs that inhibit folate metabolism.
  • For phenylketonuria, known hypersensitivity to sapropterin or excipients.
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00730080

Locations
United States, Missouri
Washington University
St. Louis, Missouri, United States, 63130
Sponsors and Collaborators
Washington University School of Medicine
BioMarin Pharmaceutical
University of Missouri-Columbia
Investigators
Principal Investigator: Desiree White, Ph.D. Washington University School of Medicine
Principal Investigator: Dorothy K. Grange, M.D. Washington University School of Medicine
  More Information

Publications:
Responsible Party: Desiree A. White, Ph.D., Associate Professor of Psychology, Washington University
ClinicalTrials.gov Identifier: NCT00730080     History of Changes
Other Study ID Numbers: PKU/Kuvan/White
Study First Received: August 1, 2008
Last Updated: August 1, 2008
Health Authority: United States: Institutional Review Board

Keywords provided by Washington University School of Medicine:
phenylketonuria
sapropterin
Kuvan
cognition
executive abilities
brain

Additional relevant MeSH terms:
Phenylketonurias
Brain Diseases, Metabolic, Inborn
Brain Diseases, Metabolic
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Amino Acid Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Metabolic Diseases

ClinicalTrials.gov processed this record on June 18, 2013