GMP-based powdered protein substitutes for phenylketonuria and tyrosinemia

Evaluating the Adherence, Tolerance, Acceptability and Safety of New GMP-based Powdered Protein Substitutes in PKU and TYR: a Case Study Series

Not applicable Interventional Nutricia UK Ltd · NCT06941532

This will test whether GMP-based powdered protein substitutes can replace regular amino-acid formulas for people with phenylketonuria or tyrosinemia to improve taste and diet adherence while keeping blood amino acids stable.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment40 (estimated)
Ages3 Years and up
SexAll
SponsorNutricia UK Ltd Industry-sponsored
Locations1 site (Birmingham)
Trial IDNCT06941532 on ClinicalTrials.gov

What this trial studies

This case-series gives participants GMP-based powdered protein substitutes that are naturally low in phenylalanine (or in both phenylalanine and tyrosine) and are supplemented with missing amino acids, carbohydrates, fats including DHA, fiber and micronutrients. Eligible participants over age 3 who have been taking at least one protein substitute (providing ≥15 g protein equivalents) for at least one month will replace at least one sachet per day with a GMP product. Investigators will monitor metabolic markers (blood phenylalanine and tyrosine), product tolerability, dietary adherence and acceptability, and safety outcomes. The work is sponsored by Nutricia UK Ltd and conducted at Birmingham Women and Children's Hospital as a non-randomized case-series format.

Who should consider this trial

Good fit: People aged over 3 with any phenotype of PKU (hyperphenylalaninaemia) or diagnosed tyrosinemia who have been taking at least one protein substitute providing ≥15 g protein equivalents for at least one month and can take at least one sachet of the GMP product per day are ideal candidates.

Not a fit: Pregnant or lactating individuals, those requiring parenteral nutrition, people with major hepatic or renal dysfunction, known allergy to product ingredients, or those unable/unwilling to comply with powdered supplement intake are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, these GMP-based powders could make it easier for people with PKU or TYR to stick to their low-phenylalanine/tyrosine diets by offering better-tasting, nutritionally complete alternatives while maintaining metabolic control.

How similar studies have performed: Previous small studies and case reports have suggested that GMP-based foods can improve taste and adherence while maintaining metabolic control in PKU patients, though larger controlled trials are limited.

Eligibility criteria

Show full inclusion / exclusion 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

Where this trial is running

Birmingham

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions PhenylketonuriaTyrosinemia
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.