Phenylketonuria (PKU)NCT07671859
PKU Microtablets Case Studies
A study testing PKU Microtablet protein substitute in people with Phenylketonuria (PKU), run by Nutricia UK Ltd at 1 site in United Kingdom.
Trial summary
Phenylalanine (Phe) free protein substitutes are typically presented in ready to drink liquid or powder format and are made up with water to a set volume. Despite recent advancements related to the taste, scent and texture of commercially available protein substitutes, a proportion of PKU patients choose to consume… Read more about this study
- Who is it for?
- Ages 4 years and older
- Conditions the study is for
- Phenylketonuria (PKU)
- What is being tested?
- PKU Microtablet protein substitute
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Oct 2026to 1 Jul 2027
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Male or female
- Over 4 years of age
- Patients diagnosed with any phenotype of PKU characterised by hyperphenylalaninaemia
- Have been compliant in taking at least one protein substitute, providing at least 20g protein equivalent, for at least 1 month prior to trial commencement
- Have a prescribed daily phenylalanine allowance for PKU
- 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 20g protein equivalent of the case study product per day
Who cannot join
- 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
- Treatment with Sapropterin dihydrochloride for less than 6 months
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site
University Hospitals Bristol and Weston NHS Foundation Trust
Bristol
About this study
Official title: Evaluating the Adherence, Tolerance, Acceptability and Safety of a New Amino Acid Based, Microtablet Protein Substitute in PKU: a Case Study Series
Phenylalanine (Phe) free protein substitutes are typically presented in ready to drink liquid or powder format and are made up with water to a set volume. Despite recent advancements related to the taste, scent and texture of commercially available protein substitutes, a proportion of PKU patients choose to consume tablet-based protein substitutes. Protein substitutes in tablet format may help overcome taste, scent and texture concerns associated with powdered and liquid preparations. Indeed, previous research has shown that protein substitute tablets are an effective strategy to manage PKU in children, teenagers and adults. Nonetheless, the daily burden and discipline required often impedes compliance, especially alongside the restrictive low-protein diet. Achieving compliance with multivitamin supplements when given alongside protein substitutes therefore becomes especially challenging. This is particularly true for adolescent, adult and maternal populations.
PKU Microtablets have recently been developed. PKU Microtablets are a new phenylalanine-free tablet protein substitute combined with vitamins, minerals and trace elements. As patient acceptability is fundamental to the successful use of any protein substitute, investigation is needed to assess the compliance, tolerance and acceptability of PKU Microtablets as part of a low phenylalanine dietary regimen in PKU patients.
This series of case-studies aims to evaluate the gastrointestinal tolerance, acceptability, compliance, and safety of this protein substitute in both adults and children from 4 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.
- Conditions
- Phenylketonuria (PKU)
- Being tested
- PKU Microtablet protein substitute
- Medical subject headings
- Phenylketonurias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PKU Microtablet protein substituteDietary supplement
PKU Microtablet intervention product
| Study group | Role | What they receive |
|---|---|---|
| PKU Microtabet intervention product | Experimental | Dietary Supplement: PKU Microtablet intervention product Receives: Dietary Supplement: PKU Microtablet protein substitute |
What is being measured
The primary outcome is the main question the study is designed to answer.
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).
Measured: Measured at baseline (day 1) and end of intervention (day 29)
Secondary outcomes (7)
Acceptability
Acceptability (ease of use and liking) of the patients' usual protein substitute and the study product will be assessed by the Dietitian at baseline (Day 1) and the end of the case study period (Day 29) by a series of questions posed to the patient and/or parent/caregiver. Acceptability questions will assess the patient's sensory experience, ease of use, tolerance, and overall self-rated acceptability on a 5-point Likert scale from Terrible (worst) to Great (best).
Measured: Measured at baseline (day 1) and end of intervention (day 29)
Compliance
Compliance with the recommended intake of the patients' usual protein substitute (during baseline) and with the study product (during the case study period) will be assessed by the Dietitian at baseline (Day 1) and at the end of the case study (Day 29). Patients and/or parents/caregivers will be asked to recall the amount of their protein substitute taken in the past 24 hours and on average. This will be compared to the amount recommended to be consumed by their Dietitian. The daily amount prescribed by the Dietitian managing the patient's care will be recorded at the start of the case study and any changes to this prescription during the case study will also be noted.
Measured: Measured at baseline (day 1) and end of intervention (day 29)
Blood Phe and Tyrosine
Participants will be required to provide a total of two fasting fingerprick blood samples as dried blood spots; one on the first day of the intervention period (Day 2) before consuming any of the case study product, and one at the end of the intervention period (Day 29). These tests will be conducted in addition to any usual blood tests the participants conduct as part of their usual disease management, which vary in frequency with the age of the participant and the local policy. Dietitians will also be asked to describe the patient's metabolic control during the case study period.
Measured: Day 2 (baseline) and day 29 (end of intervention)
Anthropometry - Height
Height will be measured, using standard methods, recorded to the nearest 0.1cm (at baseline only) and used to calculate body mass index (BMI, kg/m2).
Measured: Day 1 (baseline) and day 29 (end of intervention)
Anthropometry - Weight
For safety purposes, at baseline (Day 1) and at the end of the case study (Day 29), body weight (kg) will be measured where possible using standard methods, recorded to the nearest 0.1kg using a weighing scale without heavy clothing.
Measured: Day 1 (baseline) and day 29 (end of intervention)
Patient History
A detailed patient history will be recorded at baseline to assess previous compliance to protein substitutes, relevant medical and clinical issues, medication(s) prescribed, and any other relevant information related to the patient's condition or dietary management.
Measured: Day 1 (baseline) and day 29 (end of intervention)
Safety/ Adverse events
All adverse events will be recorded, throughout the case study.
Measured: Throughout the case study series (day 1 to day 29).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jun 2026
- Study start1 Oct 2026 (estimated)
- Primary completion1 Jun 2027 (estimated)
- Study completion1 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Phenylketonuria (PKU)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nutricia UK Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Gary Hubbard, Dr, Study director, Nutricia, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07671859
- Sponsor's protocol ID
- PKUM2025
- Status last verified
- Sep 2026
- First submitted
- 17 Jun 2026
- Last updated
- 23 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No