Clinical trial NCT06941532: GMP Powdered Substitutes in PKU and TYR
Official title: Evaluating the Adherence, Tolerance, Acceptability and Safety of New GMP-based Powdered Protein Substitutes in PKU and TYR: a Case Study Series
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Phenylketonuria
Tyrosinemia
Lead sponsor: Nutricia UK Ltd
Sponsor class: INDUSTRY
First posted: 2025-04-23
Enrollment: 40
Sex: ALL
Minimum age (years): 3
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: Four new GMP-based protein substitutes have been developed to support the dietary management of PKU and TYR. These products are powdered protein substitutes, low in phenylalanine and low in phenylalanine and tyrosine respectively, with a mix of glycomacropeptide (GMP), essential and non-essential amino acids, carbohydrates, fibres, fats (including DHA) and micronutrients. The proteins in these new protein substitutes are based on GMP, a peptide isolated from milk during cheese manufacturing and the only known naturally derived protein source low in phenylalanine and tyrosine. The GMP is supplemented with other amino acids which are naturally low or not present in GMP, as well as carbohydrates, fats, fibre and micronutrients. Studies to date have illustrated that PKU patients who replace their regular phenylalanine-free amino acid-based formula with GMP-based foods may have better diet compliance and prefer the taste whilst maintaining metabolic control.

This series of case-studies aims to evaluate the gastrointestinal tolerance, acceptability, compliance, and safety of these four GMP based protein substitutes in both adults and children over 3 years. These case studies will last 29 days in total, including a 1-day baseline period followed by a 28-day intervention period. The case studies will be conducted across multiple specialist metabolic centres in the UK. A series of case studies is undertaken due to the rarity of these conditions, the diversity of patient types and the difficulty in recruiting these patients to trials.


Eligibility criteria: Inclusion Criteria:

* Male or female
* Over 3 years of age
* Patients diagnosed with any phenotype of PKU characterised by hyperphenylalaninaemia or patients diagnosed with tyrosinaemia
* Have been compliant in taking at least one protein substitute, providing at least 15g protein equivalents, for at least 1 month prior to trial commencement
* Have a prescribed daily phenylalanine or phenylalanine and tyrosine allowance for PKU or TYR respectively
* Written or electronic informed consent from patient, and/or from parent/caregiver if applicable
* Participants who are anticipated to be able to take at least one sachet of GMP Product per day

Exclusion Criteria:

* Pregnant or lactating
* Requiring parenteral nutrition
* Major hepatic or renal dysfunction
* Participation in other studies within 1 month prior to entry of this study
* Allergy to any of the study product ingredients
* Investigator concern around willingness/ability of patient or parent/caregiver to comply with protocol requirement

Primary outcomes:
measure: Gastro-intetsinal tolerance
timeFrame: Measured at baseline (day 1) and end of intervention (day 29)
Secondary outcomes:
measure: Acceptability
timeFrame: Measured at baseline (day 1) and end of intervention (day 29)
measure: Compliance
timeFrame: Measured at baseline (day 1) and end of intervention (day 29)
measure: Blood phenylalanine, blood tyrosine and other amino acid levels
timeFrame: Day 1 (baseline) and day 29 (end of intervention)
measure: Anthropometry
timeFrame: Day 1 (baseline) and day 29 (end of intervention)
measure: Patient history
timeFrame: Day 1 (baseline) and day 29 (end of intervention)
measure: Safety/ Adverse Events
timeFrame: Throughout the case study series (day 1 to day 29).
Other outcomes:
Locations:
Study officials:
affiliation: Nutricia UK Ltd
name: Gary Hubbard, Dr
role: STUDY_DIRECTOR
References: