Phenylketonuria (PKU) and HyperphenylalaninemiaXPhePiccosMRNCT07802366
Market Research of a Slow Release Protein Substitute for the Dietary Management of PKU
A study testing Slow release, phenylalanine-free protein substitute tablets in people with Phenylketonuria (PKU) and Hyperphenylalaninemia and Brain Diseases, Metabolic, Inborn, run by metaX Institut fuer Diatetik GmbH at 1 site in United Kingdom.
Trial summary
XPhePiccosMR is a prospective, single-arm, open label, observational study that aims to evaluate the acceptability and tolerability of XPhe Piccos, a slow-release, phenylalanine-free protein substitute in the form of tiny tablets, for use in the dietary management of phenylketonuria (PKU) in children aged three years… Read more about this study
- Who is it for?
- Ages 3 to 18 years
- Conditions the study is for
- Phenylketonuria (PKU) and Hyperphenylalaninemia, Brain Diseases, Metabolic, Inborn, Brain Disorder, Metabolic
- What is being tested?
- Slow release, phenylalanine-free protein substitute tablets
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 15 Oct 2026to 1 Aug 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 3 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Diagnosis of PKU or HPA requiring a phenylalanine-free protein substitute.
- Subjects who are already taking a phenylalanine-free protein substitute and are willing to try the study product for 7 days.
- Subjects aged 3 years and above.
- Written informed assent/consent obtained from subject and/or parental caregiver, depending on subject age.
Who cannot join
- Presence of serious concurrent illness.
- Lead Dietitian's uncertainty about the willingness or ability of the patient to comply with the protocol requirements
- Participation in any other studies involving investigational or marketed products concomitantly or within two weeks prior to entry into the study.
- Any subject having taken antibiotics over the previous 2 weeks leading up to the study.
- Subjects less than 3 years of age
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
Birmingham Children´s Hospital
Birmingham, England, B4 6NH
Anita MacDonald, Professor, +44 1213338024, anita.macdonald@nhs.net
About this study
Official title: XPhe Piccos - Acceptability and Tolerance Market Research
XPhePiccosMR is a prospective, single-arm, open label, observational study that aims to evaluate the acceptability and tolerability of XPhe Piccos, a slow-release, phenylalanine-free protein substitute in the form of tiny tablets, for use in the dietary management of phenylketonuria (PKU) in children aged three years and older.
Read the detailed description
The principle treatment for children with Phenylketonuria (PKU) or Hyperphenylalaninemia (HPA) is a low protein diet. Part of this treatment requires the administration of a protein substitute in order to meet basic protein requirements for normal growth and development. Several brands of protein substitutes for PKU/HPA are already available in various presentations. However, compliance with taking protein substitutes continues to be a challenge. As a low protein diet is usually recommended for life, long term compliance is always a major concern. As a result, improving the choice in terms of product type may aid compliance.
XPhe Piccos is a slow release, phenylalanine-free protein substitute in a tiny tablet form, enriched with vitamins, minerals and trace elements and designed for children and adults with PKU/HPA. XPhe Piccos is a food for special medical purposes (FSMP), as defined by the Delegated Regulation (EU) 2016/128 of 25 September 2015 supplementing Regulation (EU) No 609/2013 of 12 June 2013, used for the dietary management of PKU/HPA.
It is anticipated that XPhe Piccos will be a suitable alternative option for patients with PKU/HPA broadening the variety of protein substitutes they can choose from in order to suit their lifestyle and preferences.
This is a prospective, single-arm, open-label, observational tolerance study with 10 children with PKU. Subjects who are currently taking a second stage protein substitute will be recruited for a 7-day trial, taking the new ready-to-use slow release, phenylalanine-free protein substitute tablets to evaluate the tolerability and acceptability of the study product. Therefore, subjects will replace some or all of their usual protein substitute with the new product.
During the 7-day trial subjects or caregivers will be asked to complete a daily questionnaire recording information on:
- Usage and compliance
- Ease of use and any issues with administration
- Any gastro-intestinal side-effects.
A questionnaire will also be completed at the beginning and end of the study that will consider perceptions about taste, appearance, smell, ease of administration of the usually used product and the study product; how it is taken; and any other problems or symptoms.
The amount of tablets prescribed will be calculated to provide the same amount of protein as their usual protein substitute.
Subjects will continue to have weekly finger-prick blood spot tests as is routine in PKU. The results whilst on the study product will be compared with results whilst on their usual protein substitute.
10 children with PKU will be recruited. When an appropriate subject has been identified, a study information sheet will be sent to the subject or parents/ caregivers. They will be invited to request further information about the study if they wish by contacting the Lead Dietitian.
Recruitment of each patient will be by written informed consent, which will be completed by the parents/ primary caregivers and taken by the Lead Dietitian. Children will also complete an assent/consent form and will receive an information sheet, if considered appropriate for their level of understanding.
- Conditions
- Phenylketonuria (PKU) and Hyperphenylalaninemia, Brain Diseases, Metabolic, Inborn, Brain Disorder, Metabolic, Brain Diseases, Central Nervous System Diseases, Nervous System Diseases
- Being tested
- Slow release, phenylalanine-free protein substitute tablets
- Keywords
- PKU, HPA, protein substitute, 7-day trial, slow release
- Medical subject headings
- Phenylketonurias, Brain Diseases, Metabolic, Inborn, Brain Diseases, Metabolic, Brain Diseases, Central Nervous System Diseases, Nervous System Diseases, Amino Acid Metabolism, Inborn Errors, Metabolism, Inborn Errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Slow release, phenylalanine-free protein substitute tabletsDietary supplement
The slow release, phenylalanine-free protein substitute in tablet form (XPhe Piccos) is a food for special medical purposes (FSMP) for use in the dietary management of Phenylketonuria or Hyperphenylalaninemia. The product is suitable from 3 years of age and over.
XPhe Piccos are a highly concentrated phenylalanine-free protein supplement in the form of very small tablets/pellets enriched with vitamins, minerals and trace elements. XPhe Piccos are characterized by a prolonged release of the amino acids.
| Study group | Role | What they receive |
|---|---|---|
| Participant group | Experimental | Subjects who are currently taking a second stage phenylalanine-free/low-Phe protein substitute will be recruited. Subjects will take the study product for 7 days. Subjects will replace some or their entire protein substitute with the study product. The appropriate amount of protein substitute will be calculated to provide the same amount of protein as their usual protein substitute. Intervention: Dietary Supplement: Slow release, phenylalanine-free protein substitute tablets. Receives: Dietary Supplement: Slow release, phenylalanine-free protein substitute tablets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of patient compliance with consumption of the prescribed volume of study product
Compliance with the recommended intake of the usually prescribed protein substitute is assessed by the dietitian at baseline. Usage and compliance with the study product are recorded daily from day 1 to day 7 using a standardised form. Using the form, patients have to record the amount of the study product consumed in comparison to the prescribed doses. The reason for not consuming the full dose will be recorded by the patient/parent/caregiver as free text. Patients are asked to state whether the study product is easy to prepare with yes or no.
Measured: daily; from day 1 to day 7
Secondary outcomes (4)
Gastro-intestinal tolerance
Gastro-intestinal side effects (including diarrhoea, constipation, bloating or abdominal distension, nausea, vomiting, burping, flatulence or regurgitation and abdominal discomfort or pain) will be assessed at baseline and daily (from day 1 to day 7) via a standardised questionnaire using the following scale: none today, mild, moderate, or severe / really troublsome.
Measured: daily; from day 1 to day 7
Patient Acceptability
Accepatbility (ease of use, taste, texture, palatability) will be assessed daily during the study period and at the end of the study via a standardised questionnaire with a rating scale of 5 (great) to 1 (terrible).
Measured: daily; from day 1 to day 7
Metabolic Control
Weekly routine finger prick blood spots will be collected and analysed for phenylalanine and tyrosine as is usual clinical practice.
Measured: baseline (day 1) and day 7
Incidence of study product emergent events
All adverse events will be recorded throughout the study (as and when they occur). There is no specific time frame as the frequency of adverse events can not be predicted. But as the study product is already commercially available occurance of any adverse event is unlikely.
Measured: throughout the study; from day 1 to day 7
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Sep 2026
- Study start15 Oct 2026 (estimated)
- Primary completion1 May 2027 (estimated)
- Study completion1 Aug 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) and HyperphenylalaninemiaStudies 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
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- open-label, observational
- Masking
- None (open label)
- Enrolment
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- metaX Institut fuer Diatetik GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Birmingham Women's and Children's NHS Foundation Trust
- Responsible party
- Sponsor
- Investigators
- Anita MacDonald, Professor, Principal investigator, Birmingham Women's and Children's NHS Foundation Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07802366
- Sponsor's protocol ID
- XPhePiccosCT01
- Acronym
- XPhePiccosMR
- Status last verified
- Oct 2026
- First submitted
- 31 Aug 2026
- Last updated
- 15 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No IPD will be shared with other researchers.