ClinicalTrials.gov record NCT07825883
The Impact of Frequency of Home Phenylalanine Measurements on Metabolic Control in a Population of Patients With Classic Phenylketonuria
The Impact of Frequency of Home Phenylalanine Measurements on Metabolic Control in a Population of Patients With Classic Phenylketonuria (FreqPHEncy) - a Single-center Randomized Cross-over Clinical Trial
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴
AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.
This randomized crossover trial compares measuring phenylalanine (Phe) at home once a week versus once a month in adults with classic phenylketonuria (PKU). Each participant follows one schedule for 24 weeks, has a 2-week washout, then follows the other schedule for 24 weeks. The study measures Phe concentration in dried blood spot (DBS) samples to assess metabolic control.
What it is studying. The study tests whether the frequency of home Phe measurements (weekly versus monthly) affects metabolic control, as measured by phenylalanine concentration in dried blood spot (DBS) samples in adults with classic PKU.
What the researchers hope to learn. The scientific goal is to obtain high-quality data on how the frequency of home Phe monitoring (once weekly versus once monthly) influences Phe control in adults with classic PKU.
What this study is about
The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.
Recommendations regarding the frequency of phenylalanine level monitoring lack solid support from evidence derived from prospective randomized trials, including in the adult population with classic PKU. Current recommendations indicate that in adults (excluding the period of pregnancy planning and pregnancy itself), Phe levels should be assessed at least once a month or more frequently if additional indications exist. As part of this study, we plan to obtain, for the first time, high-quality data on the impact of Phe monitoring frequency on Phe control in adults. The primary objective of the study will be to assess the effect of the frequency (once a week versus once a month) of Phe level measurements on the metabolic control of phenylketonuria, as expressed by Phe concentration in DBS, in adult patients with the classic form of phenylketonuria.
Interventions being studied
Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.
- Other
- DBS Phe monitoring once weekly
- DBS Phe monitoring once monthly
Eligibility
The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.
Inclusion criteria
- Informed consent to participate in the study
- Male or female participants aged ≥18 and ≤65 years
- Clinical diagnosis of classic phenylketonuria (PKU) documented in the medical history by at least 2 measurements of blood phenylalanine concentration
- ≥600 μmol/l and a predicted PAH enzyme activity <1% (GPV), requiring treatment with a low-protein diet supplemented with special low-phenylalanine amino acid mixtures
- Blood phenylalanine concentration in the range of 360-900 μmol/l during current therapy at the time of screening, and blood phenylalanine concentration in the range of 360-900 μmol/L during current treatment, based on the arithmetic mean of the last 3 Phe measurements from the participant's medical history (including the value from the screening)
- Ability and willingness, in the investigator's opinion, to comply with all requirements of the study.
Exclusion criteria
- Patients who have not followed a phenylalanine (Phe)-restricted diet for 6 months prior to the start of the study or who are not willing to continue this diet 2. Phe concentration > 900 μmol/L in any measurement taken within 6 months prior to the start of the study 3. Drug or alcohol abuse 4. A person who, in the investigator's opinion, is unable or unwilling to comply with the study requirements. Persons who are legally incapacitated will not be eligible to participate in the study 5. Current participation in another clinical trial or use of any experimental drug within 30 days prior to screening 6. Planning a pregnancy or being pregnant 7. Confirmed diagnosis of primary BH4 deficiency, documented by the presence of pathogenic mutations in both alleles of the following genes: 6-pyroyl-tetrahydrobiopterin synthase, recessive guanosine triphosphate (GTP) cyclohydrolase, sepiapterin reductase, dihydropteridine quinonoid reductase, or pterin 4 alpha-carbinolamine dehydratase 8. Use of sapropterin, sepiapterin, or pegvaliaza concurrently or within 365 days prior to screening
Study description and what participation involves
The registry record has no detailed description beyond the summary above.
AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴
AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.
You will be randomly assigned to one of two crossover sequences: weekly dried blood spot (DBS) phenylalanine (Phe) monitoring for 24 weeks, then a 2-week washout, then monthly DBS Phe monitoring for 24 weeks; or the reverse (monthly first, then weekly). During each intervention period you will collect DBS samples at the assigned frequency (once a week or once a month) so your Phe concentration in DBS can be followed over time; the study compares changes from each period's baseline to the average of months 5 and 6. The registry record does not list other study procedures or visits beyond these monitoring periods and the 2-week washout.
How the study is structured. Participants are randomly assigned to one of two sequences in an open-label (unmasked) crossover design. Sequence 1: weekly DBS Phe measurements for 24 weeks, then a 2-week washout, then monthly DBS Phe measurements for 24 weeks. Sequence 2: the same two measurement schedules in the opposite order. The primary outcome is the change in DBS Phe concentration from the start of an intervention period to the average of months 5 and 6 of that period.
Questions you could ask
These questions are suggestions for a conversation with the study team or your own clinician, not advice.
- The listed sites are in Poland. Is any of them reachable for me, and does the study help with travel?
- Which of the eligibility criteria would need to be checked with tests before I could join?
More on phenylketonuria
Important dates
- Study start
- Sep 11, 2026
- Primary completion
- Mar 31, 2028 (estimated)
- Study completion
- Dec 31, 2028 (estimated)
- Target enrollment
- 36 participants (estimated)
- Last updated on registry
- Sep 17, 2026
- Data verified
- Oct 10, 2026
Sponsor and research team
The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.
- Lead sponsor
- Michał Kania
- Collaborators
- Jagiellonian University Medical College - Department and Clinic of Metabolic Diseases (Katedra i Klinika Chorób Metabolicznych UJ)
- Polskie Towarzystwo Wrodzonych Was Metabolizmu
Central study contact
If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.
- Michal Kania, MD, PhD 📞 +48124002950 ✉ mich.kania@uj.edu.pl
Participating sites (1)
- Department of Diabetology, Internal Medicine, and Metabolic Diseases, Metabolic Diseases Clinic, University Hospital in KrakówRecruiting
Krakow, 30-688 · Poland
- Michal Kania, MD, PhD · +48124002950 · mich.kania@uj.edu.pl
Terms used on this page · explanations by MedicalUpdates.ai
- randomized
- Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
- primary objective
- The main result the study is designed to measure and report on. Other results, called secondary outcomes, are also collected.
- Informed consent
- The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
- prior to screening
- The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
- Inclusion Criteria
- The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
- Exclusion Criteria
- The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.
← Back to clinical trials