Phenylketonuria (PKU)FreqPHEncyNCT07825883
The Impact of Frequency of Home Phenylalanine Measurements on Metabolic Control in a Population of Patients With Classic Phenylketonuria
A study testing DBS Phe monitoring once weekly and DBS Phe monitoring once monthly in people with Phenylketonuria (PKU), run by Michał Kania at 1 site in Poland.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Phenylketonuria (PKU)
- What is being tested?
- DBS Phe monitoring once weekly and DBS Phe monitoring once monthly
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 sitePoland
- Study dates
- 11 Sep 2026to 31 Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 1. 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Poland1 site, 1 recruiting
- Recruiting
Department of Diabetology, Internal Medicine, and Metabolic Diseases, Metabolic Diseases Clinic, University Hospital in Kraków
Krakow, 30-688
Michal Kania, MD, PhD, +48124002950, mich.kania@uj.edu.pl
About this study
Official title: 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
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.
- Conditions
- Phenylketonuria (PKU)
- Being tested
- DBS Phe monitoring once weekly, DBS Phe monitoring once monthly
- Keywords
- phenylketonuria, PKU, hyperphenylalaninemia, dried blood spot, DBS, phenylalanine, Phe, monitoring
- Medical subject headings
- Phenylketonurias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DBS Phe monitoring once weeklyOther
In the intervention period participants will measure their Phe levels via DBS once a week as compared to once weekly.
DBS Phe monitoring once monthlyOther
In the control period participants will measure their Phe levels via DBS once monthly.
| Study group | Role | What they receive |
|---|---|---|
| Sequence 1 | Experimental | Sequence 1 starts with intervention period 1 with DBS Phe measurements once a week for 24 weeks, followed by a 2-week wash-out period and intervention period 2 with DBS Phe measurements once a month for 24 weeks. Receives: Other: DBS Phe monitoring once weekly; Other: DBS Phe monitoring once monthly |
| Sequence 2 | Experimental | Sequence 2 starts with intervention period 1 with DBS Phe measurements once a month for 24 weeks, followed by a 2-week wash-out period and intervention period 2 with DBS Phe measurements once a week for 24 weeks. Receives: Other: DBS Phe monitoring once weekly; Other: DBS Phe monitoring once monthly |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Phe concentration in the DBS measurement
Change in Phe concentration in the DBS measurement from the baseline (O1) to the 5th and 6th months in each intervention period (average of measurements O140 and O168 [measurements once a month] OR O119 O168 [measurements taken once a week]).
Measured: from the baseline (O1) to the 5th and 6th months in each intervention period (average of measurements O140 and O168 [measurements once a month] OR O119 O168 [measurements taken once a week]).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2026
- Study start11 Sep 2026
- Primary completion31 Mar 2028 (estimated)
- Study completion31 Dec 2028 (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
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Michał Kania
- Sponsor type
- University, hospital or other
- Collaborators
- Jagiellonian University Medical College - Department and Clinic of Metabolic Diseases (Katedra i Klinika Chorób Metabolicznych UJ), Polskie Towarzystwo Wrodzonych Was Metabolizmu
- Responsible party
- Sponsor-investigator, Michał Kania, Jagiellonian University
- Investigators
- Michal Kania, Principal investigator, Michał Kania
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07825883
- Sponsor's protocol ID
- 1072.6120.1.16.2026
- Acronym
- FreqPHEncy
- Status last verified
- Sep 2026
- First submitted
- 12 Sep 2026
- Last updated
- 17 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Sponsor requirement.
Study at a glance
From the registry record, last updated by the sponsor on 17 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07825883
- Acronym / sponsor ID
- FreqPHEncy / 1072.6120.1.16.2026
- Conditions
- Phenylketonuria (PKU)
- Keywords
- phenylketonuria, PKU, hyperphenylalaninemia, dried blood spot, DBS, phenylalanine, Phe, monitoring
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Michał KaniaUniversity, hospital or other
- Collaborators
- Jagiellonian University Medical College - Department and Clinic of Metabolic Diseases (Katedra i Klinika Chorób Metabolicznych UJ), Polskie Towarzystwo Wrodzonych Was Metabolizmu
- Study start
- 11 Sep 2026 (actual)
- Primary completion
- 31 Mar 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 17 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sequence 1 | Experimental | Other: DBS Phe monitoring once weekly, Other: DBS Phe monitoring once monthlySequence 1 starts with intervention period 1 with DBS Phe measurements once a week for 24 weeks, followed by a 2-week wash-out period and intervention period 2 with DBS Phe measurements once a month for 24 weeks. |
| Sequence 2 | Experimental | Other: DBS Phe monitoring once weekly, Other: DBS Phe monitoring once monthlySequence 2 starts with intervention period 1 with DBS Phe measurements once a month for 24 weeks, followed by a 2-week wash-out period and intervention period 2 with DBS Phe measurements once a week for 24 weeks. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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)
Key exclusion criteria (1 listed)
- 1. 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DBS Phe monitoring once weeklyIn the intervention period participants will measure their Phe levels via DBS once a week as compared to once weekly. | Other | Sequence 1, Sequence 2 |
| DBS Phe monitoring once monthlyIn the control period participants will measure their Phe levels via DBS once monthly. | Other | Sequence 1, Sequence 2 |
Primary outcome
Change in Phe concentration in the DBS measurement
Time frame: from the baseline (O1) to the 5th and 6th months in each intervention period (average of measurements O140 and O168 [measurements once a month] OR O119 O168 [measurements taken once a week]).
Change in Phe concentration in the DBS measurement from the baseline (O1) to the 5th and 6th months in each intervention period (average of measurements O140 and O168 [measurements once a month] OR O119 O168 [measurements taken once a week]).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Sep 2026.
- Individual participant dataSharing planned: No. Sponsor requirement.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Michal Kania principal investigator
Michał Kania
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing DBS Phe monitoring once weekly and DBS Phe monitoring once monthly in people with Phenylketonuria (PKU), run by Michał Kania at 1 site in Poland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 17 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Michal Kania, MD, PhD (+48124002950, mich.kania@uj.edu.pl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Phe concentration in the DBS measurement (time frame: from the baseline (O1) to the 5th and 6th months in each intervention period (average of measurements O140 and O168 [measurements once a month] OR O119 O168 [measurements taken once a week]).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Sep 2026.