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A 16 Week Study Evaluating the Introduction of a GMP Based Protein Substitute in Participants With PKU

Not Applicable
Completed
Conditions
Phenylketonurias
Interventions
Dietary Supplement: PKU Sphere
Registration Number
NCT03771391
Lead Sponsor
Vitaflo International, Ltd
Brief Summary

This study aims to measure changes in participants' blood phenylalanine (Phe) levels in participants with PKU when switching from a conventional amino acid based protein substitute to a GMP based protein substitute (PKU Sphere) over a 16 week period.

Detailed Description

This is a stepped wedge, open-label study of PKU Sphere for the dietary management of participants with Phenylketonuria. It will be carried out with 33 participants who will be randomised into one of three clusters. The total study length per patient is 16 weeks. Each cluster transitions from taking their standard amino acid product alone to incorporating PKU Sphere (at least 50% of their protein substitue requirement) at different timepoints: week 5, 9 or 13.

Participants will have a face-to-face clinical review at the time of recruitment (week 0) and at 16 weeks (completion of the study). They will also have an additional telephone review when they switch onto PKU Sphere.

Blood samples will be taken at baseline, and then every two weeks for the duration of the study.

In addition to these study visits and procedures, routine clinical care will continue in line with local guidelines.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
15
Inclusion Criteria
  • Diagnosis of PKU made in neonatal period
  • Treated by a low-phenylalanine diet and necessity of intake of at least one protein substitute per day
  • Aged 10 years and above
  • Three blood Phe measurements taken within the preceding six months
  • Willing to replace current amino acid based protein substitute with PKU Sphere
  • Ability to take at least 50% of protein requirements as PKU Sphere
  • Ability to comply with the study protocol, in the opinion of the investigator
  • Willingly given, written, informed consent from patient or parent/guardian
  • Willingly given, written assent (if appropriate)
Exclusion Criteria
  • Women who are pregnant or planning to become pregnant during the study period
  • Participants with atypical PKU (e.g. BH4 deficient)
  • Intake of sapropterin dihydrochloride (Kuvan) in the six weeks prior to recruitment in the study
  • Patients with soya, milk or fish allergies
  • Any other severe disease

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
8 WeeksPKU SphereAll patients randomised to this arm will start on an amino acid based protein substitute and they will all swtich over to incorprating PKU Sphere after 8 weeks.
12 WeeksPKU SphereAll patients randomised to this arm will start on an amino acid based protein substitute and they will all swtich over to incorprating PKU Sphere after 12 weeks.
4 WeeksPKU SphereAll patients randomised to this arm will start on an amino acid based protein substitute and they will all swtich over to incorprating PKU Sphere after 4 weeks.
Primary Outcome Measures
NameTimeMethod
Change in blood PheBaseline (week 0) and weeks 2, 4, 6, 8, 10, 12, 14 and 16.

Change in blood Phe concentrations when switching from an amino acid based protein substitute to a GMP based one (PKU Sphere). A minimum of five (5) blood samples (including a baseline measurement and one from each treatment arm) will be required for a patient to be included in the final analysis.

Secondary Outcome Measures
NameTimeMethod
Acceptance questionnaireWeeks 1, 4, 8, 12 and 16

Questionnaire to collect information about taste, odour and practicability of the protein substitutes. The questions are answered on a scale of 1 (bad) to 5 or 6 (good). Questionnaire validated as part of a bachelor thesis.

Gastrointestinal symptoms questionnaireWeeks 1, 4, 8, 12 and 16

Short questionnaire asking participants to consider their general gastrointestinal health over the previous 7 days. The occurrence of various GI symptoms are given as never, rare, often or always. Questionnaire validated as part of a bachelor thesis.

Change in blood tyrosineBaseline (week 0) and weeks 2, 4, 6, 8, 10, 12, 14 and 16.

Impact of a GMP based protein substitute on blood tyrosine levels. A minimum of five (5) blood samples (including a baseline measurement and one from each treatment arm) will be required for a patient to be included in the final analysis.

Protein substitute intakeWeeks 1, 4, 8, 12 and 16

Compliance with the recommended volume of protein substitute - 3-day protein substitute diary.

Dietary intakeWeeks 1 and 16.

Compliance with a low protein diet - 3-day food diary.

Stool patternsWeeks 1, 4, 8, 12 and 16

3-day diary noting stool type (Bristol stool chart).

Satiety questionnaireWeeks 1, 4, 8, 12 and 16

Short questionnaire asking participants to consider their satiety levels over the last 7 days, asking them if it has increased, stayed the same or decreased. Questionnaire validated as part of a bachelor thesis.

Trial Locations

Locations (1)

Kreiskliniken Reutlingen

🇩🇪

Reutlingen, Baden-Württemberg, Germany

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