A Pilot Study on Diurnal Variation

March 21, 2016 updated by: Dr. Linda Randolph

A Pilot Study on the Diurnal Variation in PKU Patients With Kuvan

This self-controlled, prospective, pilot study is designed to gather information regarding the diurnal variation (changes that occur each day) in the levels of plasma phenylalanine (Phe) and tyrosine in patients with phenylketonuria (PKU) and in the non-PKU population.

Study Overview

Status

Terminated

Intervention / Treatment

Detailed Description

Phenylketonuria (PKU) is a rare genetic metabolic disease caused by a mutation that codes for an enzyme that converts the essential amino acid phenylalanine (Phe) into tyrosine. An absence or deficiency of this enzyme activity results in a Phe elevation, where higher Phe levels result in neurological damage. Diurnal variations of Phe levels have been observed in PKU patients in a 24-hour period.

As Kuvan has shown to stabilize Phe levels in PKU patients over time, our hypothesis is that this can be demonstrated within a 24-hour period of observation and indicate therefore that Kuvan may correlate with a lower plasma Phe variability. This study on PKU patients' diurnal variation will also provide important information as to the current method of blood Phe monitoring in a clinical setting to learn more about the optimal way to measure Phe concentration.

The study will last about 4 weeks (6 study visits) for the PKU participants and about 1 week (2 study visits) for the control group.

Participants will be required to follow a recommended diet, complete a dietary log, and undergo several blood draws, including a 24-Hour Blood Assessment in which blood will be obtained 8 times throughout the day.

Study Type

Interventional

Enrollment (Actual)

6

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • California
      • Los Angeles, California, United States, 90027
        • Children's Hospital Los Angeles

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

4 years and older (ADULT, OLDER_ADULT, CHILD)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

PKU PARTICIPANTS (ARM 1):

  • Subject has a confirmed diagnosis of PKU with hyperphenylalaninemia documented by a fasting Phenylalanine level of at least 360 umol/L (6 mg/dL)
  • Patient is at least 4 years old (there is no upper age limit for this study)
  • Willing and able to provide written authorization or, if under the age of 18 years, provide written assent (if required) and written patient authorization by a parent or legal guardian
  • Willing to undergo study related procedures including commencing Kuvan treatment for patient not currently on treatment; temporary discontinuation of Kuvan for patient on treatment; and completing the 24-Hour Blood Assessment
  • Authorized to provide personal health information
  • Subjects should not be pregnant and willing to use appropriate birth control during the study

CONTROL GROUP (ARM 2):

  • Healthy, non-PKU individuals. They will be age-sex matched to the PKU group. They may be a relative (ex: sibling) of a PKU participant, but they don't have to be a blood relation.
  • Individual is at least 4 years old (there is no upper age limit)
  • Willing and able to provide written consent or, if under the age of 18 years, provide written assent and written participant authorization by a parent or legal guardian
  • Authorized to provide personal health information

Exclusion Criteria (BOTH ARMS):

  • Subjects who do not meet all the inclusion criteria
  • Age < 4 years
  • Concomitant medical problems or medications which at the discretion of the principal investigator would put participant at health risk or prevent them from completing study.
  • If female, unwillingness to use birth control during the period of the study drug administration (this doesn't apply to Arm 2)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Allocation: NON_RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: PKU Participants (Arm 1)
  • Subjects will be administered Kuvan once daily.
  • They will undergo several blood draws, including a 24-Hour Blood Assessment (at Study Visit #2 before the commencement of Kuvan), plasma Phe/Tyr draws (at Study Visits #3, 4, and 5), and another 24-Hour Blood Assessment (at Study Visit #6).
Only PKU participants (Arm 1) will be administered Kuvan once daily either at a dose of 20 mg/kg/day (if the PKU participant is not currently taking Kuvan) or at the subject's regular dose (if the PKU participant is currently taking Kuvan). They will remain on Kuvan for 4 weeks.
NO_INTERVENTION: Control Group (Arm 2)
  • Subjects allocated into this group will be healthy, non-PKU individuals that may be a relative (ex: sibling) of a PKU participant, but they don't have to be a blood relation.
  • These subjects will undergo a 24-Hour Blood Assessment (at Study Visit #2).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Plasma Phe and Tyrosine Levels
Time Frame: Baseline and 4 weeks
To evaluate the patterns of change in plasma Phe and tyrosine levels between the Baseline visit and 4 week visit for each arm.
Baseline and 4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Linda M. Randolph, MD, Children's Hospital Los Angeles

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2013

Primary Completion (ACTUAL)

May 1, 2014

Study Completion (ACTUAL)

May 1, 2014

Study Registration Dates

First Submitted

March 4, 2013

First Submitted That Met QC Criteria

March 5, 2013

First Posted (ESTIMATE)

March 7, 2013

Study Record Updates

Last Update Posted (ESTIMATE)

April 20, 2016

Last Update Submitted That Met QC Criteria

March 21, 2016

Last Verified

March 1, 2016

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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