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Completed

NCT Number: NCT04224142

Evaluation of PKU Sphere in Maternal PKU

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.

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Key information

Conditions

Maternal Phenylketonuria Amino Acid Metabolism, Inborn Errors Brain Diseases Brain Diseases, Metabolic Brain Diseases, Metabolic, Inborn Central Nervous System Diseases Congenital, Hereditary, and Neonatal Diseases and Abnormalities Female Urogenital Diseases and Pregnancy Complications Genetic Diseases, Inborn Metabolic Diseases Metabolism, Inborn Errors Nervous System Diseases Nutritional and Metabolic Diseases Phenylketonuria, Maternal Phenylketonurias Pregnancy Complications Urogenital Diseases

Age range

16 year and older

Sex eligibility

Female

Study type

Observational

Primary location

Royal Victoria Hospital, Belfast, United Kingdom

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

PKU sphere

Dietary Supplement

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.

Primary outcomes

  1. Change in blood spot phenylalanine levels

    Time frame: Baseline, 1-2 times weekly during preconception (max. 2 years), 2-3 times weekly during pregnancy, one month postpartum.

    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.

  2. Change in blood spot tyrosine levels

    Time frame: Baseline, 1-2 times weekly during preconception (max. 2 years), 2-3 times weekly during pregnancy, one month postpartum.

    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.

  3. Change in adherence to study product intake

    Time frame: Every 12 weeks from baseline during preconception (max. 2 years) and pregnancy until the end of the pregnancy

    3-day diary recording compliance/adherence of patients to their prescribed amount of protein substitute.

  4. Participants' gastrointestinal adverse events

    Time frame: Throughout the study until one month postpartum

    Participant to report any gastrointestinal (GI) symptoms and pregnancy-associated nausea and vomiting while consuming PKU Sphere.

  5. Change in weight

    Time frame: Baseline, every 24 weeks during preconception (max. 2 years) and pregnancy, one month postpartum

    Weight (kg)

  6. Change in plasma amino acid profile

    Time frame: Baseline, all routine results during preconception (max. 2 years) and pregnancy, one month postpartum

    Plasma amino acid profile

  7. Change in plasma micronutrient profile

    Time frame: Baseline, all routine results during preconception (max. 2 years) and pregnancy, one month postpartum

    Plasma micronutrient profile

  8. Pregnancy outcome

    Time frame: End of pregnancy

    Standard of care data on the outcome of the pregnancy

Sponsors and collaborators

Lead sponsor

Vitaflo International, Ltd

Industry

Collaborators

  • University College London Hospitals

Registry information

Official study title

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

Acronym: Maternal PKU

Important dates

Study start
2019
Primary completion
2025
Study completion
2025
First posted
Jan 13, 2020
Registry last updated
Nov 28, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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