GMP Powdered Substitutes in PKU and TYR

NCT06941532 | Recruiting

• 1 other identifier: GMP2024
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

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.

Conditions

Phenylketonuria; Tyrosinemia

Outcome Measures

Primary Outcomes (1)

• Gastro-intetsinal tolerance

  GI tolerance will be recorded by the Dietitian at baseline on Day 1 and at the end of the case study period (Day 29). GI tolerance will be recorded using a standardised questionnaire to capture perceived severity (none, mild, moderate or severe) of common gastrointestinal symptoms (diarrhoea, constipation, bloating, abdominal discomfort, vomiting and nausea). Information about appearance of stools will also be collected using the Bristol Stool Chart© at the same time points.

  Measured at baseline (day 1) and end of intervention (day 29)

Secondary Outcomes (6)

• Acceptability

  Measured at baseline (day 1) and end of intervention (day 29)

• Compliance

  Measured at baseline (day 1) and end of intervention (day 29)

• Blood phenylalanine, blood tyrosine and other amino acid levels

  Day 1 (baseline) and day 29 (end of intervention)

• Anthropometry

  Day 1 (baseline) and day 29 (end of intervention)

• Patient history

  Day 1 (baseline) and day 29 (end of intervention)

Study Arms (1)

GMP intervention product

EXPERIMENTAL

Dietary Supplement: GMP Intervention Product

Interventions

GMP Intervention Product DIETARY_SUPPLEMENT

Condition specific GMP based intervention product

GMP intervention product

Eligibility Criteria

• Age: 3 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Nutricia UK Ltd: lead

Study Sites (1)

Birmingham Women and Children's Hospital

Birmingham, United Kingdom

RECRUITING

MeSH Terms

Conditions

Phenylketonurias; Tyrosinemias

Condition Hierarchy (Ancestors)

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; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Gary Hubbard, Dr

  Nutricia UK Ltd

  STUDY DIRECTOR

Central Study Contacts

Ellen Taylor

CONTACT

07900724091; ellen.taylor@nutricia.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 4, 2025
• First Posted: April 23, 2025
• Study Start: May 20, 2025
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: December 19, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)