Evaluation of PKU Sphere in Maternal PKU (Maternal PKU)

An Observational Study to Evaluate Metabolic Control and Dietary Management in Women With PKU Taking PKU Sphere During Pre-conception and/or Pregnancy

This observational study aims to recruit females, aged 16 years and over, with phenylketonuria (PKU) or hyperphenylalaninemia (hyperphe) following dietary management advice pre-conception and/or during pregnancy, who are willing to take PKU sphere as part of their dietarty management.

Study Overview

• Status: Completed
• Conditions: Maternal Phenylketonuria
• Intervention / Treatment: Dietary supplement: PKU sphere

Detailed Description

The aim of this study is to observe dietary management and metabolic control in women taking PKU sphere pre-conceptually and/or during pregnancy. To do this the following data points will be captured:

• Blood spot phenylalanine and tyrosine levels to measure metabolic control
• Changes to dietary management and any adaptations arising from incorporating PKU Sphere
• Compliance/adherence of patients to their recommended amount of protein substitute prescription.
• Tolerance of PKU sphere with respect to gastrointestinal (GI) symptoms and pregnancy associated nausea and vomiting.
• Acceptability of concurrent protein substitute(s) (if applicable).
• Nutritional status and weight management.
• Routine standard of care data on the final pregnancy outcome and postpartum.

• Study Type: Observational
• Enrollment (Actual): 12

Contacts and Locations

Study Locations

• United Kingdom
  • Belfast, United Kingdom
    • Royal Victoria Hospital
  • Cardiff, United Kingdom
    • University Hospital of Wales
  • London, United Kingdom
    • University College London Hospitals NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Maternal and preconception females, aged 16 years onwards with phenylketonuria (PKU) requiring dietary management with protein substitutes.

Description

Inclusion Criteria:

• Diagnosis of phenylketonuria (PKU) or hyperphenylalaninemia (hyperphe) which requires dietary management during pre-conception and/or pregnancy.
• Aged 16 years and above.
• Following dietary management advice pre-conceptually and/or during pregnancy, aiming for phenylalanine levels of 120-250µmol/L.
• Prior positive PKU sphere taste test completed as part of routine care.
• Chosen to take part or full requirement of protein substitute as PKU sphere pre-conceptually and/or during pregnancy.
• Willingly given, written, informed consent from patient.
• Participant is, in the opinion of the investigator, able to participate and can comply with the study protocol.

Exclusion Criteria:

• Conception of pregnancy without commencement of phe-restricted diet and blood phenylalanine not maintained within target range by 10 weeks' gestation.
• Patients with known soya, milk or fish allergies / intolerance.
• Intake of pegvaliase or large neutral amino acids within 30 days prior to screening visit.
• Patients who are currently participating in, plan to participate in, or have participated in an interventional investigational drug, food or medical device trial within 30 days prior to screening visit.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

PKU sphere; PKU sphere (an FSMP) as per individual requirements determined by a dietitian.

Dietary supplement: PKU sphere; PKU sphere is a Food for Special Medical Purposes (FSMP). This product is for use in the dietary management of phenylketonuria (PKU). It is a powdered, low phenylalanine medical food containing a balanced mix of GMP, essential and non-essential amino acids, carbohydrate, fat, vitamins, minerals, and DHA. It is available in 27g sachets providing 15g PE and contains 28mg Phe and 35g sachets providing 20g PE and contains 36mg Phe.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in blood spot phenylalanine levels	Measurement of fasting phenylalanine concentrations completed once (1) to twice (2) weekly preconception (which may last for an indeterminate amount of time), twice (2) to three (3) times weekly during pregnancy and one month postpartum. Collected as dried bloodspots on Guthrie cards in the patient's own home and posted to the hospital laboratory for analysis.	Baseline, 1-2 times weekly during preconception (max. 2 years), 2-3 times weekly during pregnancy, one month postpartum.
Change in blood spot tyrosine levels	Measurement of fasting tyrosine concentrations completed once (1) to twice (2) weekly preconception (which may last for an indeterminate amount of time), twice (2) to three (3) times weekly during pregnancy and one month postpartum. Collected as dried bloodspots on Guthrie cards in the patient's own home and posted to the hospital laboratory for analysis.	Baseline, 1-2 times weekly during preconception (max. 2 years), 2-3 times weekly during pregnancy, one month postpartum.
Change in adherence to study product intake	3-day diary recording compliance/adherence of patients to their prescribed amount of protein substitute.	Every 12 weeks from baseline during preconception (max. 2 years) and pregnancy until the end of the pregnancy
Participants' gastrointestinal adverse events	Participant to report any gastrointestinal (GI) symptoms and pregnancy-associated nausea and vomiting while consuming PKU Sphere.	Throughout the study until one month postpartum
Change in weight	Weight (kg)	Baseline, every 24 weeks during preconception (max. 2 years) and pregnancy, one month postpartum
Change in plasma amino acid profile	Plasma amino acid profile	Baseline, all routine results during preconception (max. 2 years) and pregnancy, one month postpartum
Change in plasma micronutrient profile	Plasma micronutrient profile	Baseline, all routine results during preconception (max. 2 years) and pregnancy, one month postpartum
Pregnancy outcome	Standard of care data on the outcome of the pregnancy	End of pregnancy

Collaborators and Investigators

• Sponsor: Vitaflo International, Ltd
• Collaborators: University College London Hospitals
• Investigators: Principal Investigator: Charlotte Ellerton, University College London Hospitals

Study record dates

Study Major Dates

• Study Start (Actual): July 29, 2019
• Primary Completion (Actual): October 7, 2025
• Study Completion (Actual): October 7, 2025

Study Registration Dates

• First Submitted: October 7, 2019
• First Submitted That Met QC Criteria: January 7, 2020
• First Posted (Actual): January 13, 2020

Study Record Updates

• Last Update Posted (Actual): November 28, 2025
• Last Update Submitted That Met QC Criteria: November 26, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Maternal; Phenylketonuria; PKU; GMP; Glycomacropeptide
• Additional Relevant MeSH Terms: Urogenital Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Metabolic Diseases; Pregnancy Complications; Brain Diseases, Metabolic, Inborn; Brain Diseases, Metabolic; Amino Acid Metabolism, Inborn Errors; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Nutritional and Metabolic Diseases; Phenylketonurias; Phenylketonuria, Maternal
• Other Study ID Numbers: MCT-GMP-2018-08-14; 256857 (Other Identifier: IRAS); 19/NW/0167 (Other Identifier: HRA)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No