Phe for Me? The Effects of L-Phe on PKU Carriers and Non-... | NCT06119048

Studies
Phe for Me? The Effects of L-Phe on PKU Carriers and Non-carriers

NCT06119048

Sponsor

University of Guelph

Status

Completed

Last Update Posted

May 4, 2026Actual

Enrollment

56Actual

Phase

Not Applicable

Conditions

Autosomal Recessive Disorder (Genetic Carriers of PKU)

Interventions

L-Phenylalanine

Countries

Canada

Protocol Section

Identification Module Status Module Sponsor/Collaborators Module Oversight Module Description Module Conditions Module Design Module Arms/Interventions Module Outcomes Module Eligibility Module Contacts/Locations Module References Module IPD Sharing Statement Module

Results Section

Participant Flow Module Baseline Characteristics Module Outcome Measures Module Adverse Events Module More Info Module

Annotation Section

Annotation Module

Document Section

Large Document Module

Derived Section

Miscellaneous Info Module Condition Browse Module Intervention Browse Module

Protocol Section

Identification Module

NCT ID

Results Section

No data available

No data is available for this block.

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Version Holder

Status Module

Record Verification Date

Apr 2026

Overall Recruitment Status or Expanded Access Status

Completed

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

Not provided

Expanded Access Info

Start Date

Jun 18, 2024Actual

Primary Completion Date

Oct 3, 2025Actual

Completion Date

Oct 3, 2025Actual

First Submitted Date

Oct 31, 2023

First Submission Date that Met QC Criteria

Oct 31, 2023

First Posted Date

Nov 7, 2023Actual

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

Apr 28, 2026

Last Update Posted Date

May 4, 2026Actual

Sponsor/Collaborators Module

Responsible Party, by Official Title

Justine Keathley, Assistant Professor, University of GuelphPrincipal Investigator

Lead Sponsor

University of GuelphOTHER

Collaborators

Name	Class
McMaster University	OTHER
Laval University	OTHER

Oversight Module

Has Data Monitoring Committee (DMC)

Not provided

Is FDA Regulated Drug

Is FDA Regulated Device

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

Brief Summary

This is a clinical intervention study of PKU carriers (cases) and non-carriers (controls). Upon completing the informed consent process, participants will complete baseline measures of chronic mental health prior to the intervention (PHQ-9, GAD-7, BIS-11). Participants will attend the Human Nutraceutical Research Unit (HNRU) at the University of Guelph, fasted, and first undergo baseline measures of cognition and acute mental health (mood) and provide samples or saliva, urine and dried blood spots to evaluate phenylalanine (Phe), tyrosine (Tyr) and their metabolites (PAH pathway functioning) as well as for genetic testing of the PAH gene. Participants will also complete a brief questionnaire which will include age, sex, ethnicity, income, weight and height (measured using a stadiometer and calibrated weigh scale), and confirmation that participants arrived to the lab fasted (i.e. have only had water to drink and no other foods/ beverages prior to analyses). Blood pressure and heart rate will also be measured at baseline.

Following baseline tests, participants will consume a pure L-Phe supplement dosed at 100 mg/kg mixed with 125 mL of water and 125mL of orange juice. Blood pressure and heart rate will be repeated at 1-hour post-L-Phe consumption. Two-hours postprandial, participants will repeat the cognitive tests and acute mental health (mood) assessment, blood pressure and heart rate measurement and provide follow-up saliva, urine and dried blood spot samples. Participants will also be asked to report any side effects they experienced with the L-Phe consumption.

Detailed Description

Not provided

Design Module

Study Type

Interventional

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Not provided

Target Follow-Up Duration

Not provided

Phases

Not Applicable

Interventional Study Design

Allocation

Biospecimen

No data available

No data is available for this block.

Enrollment

56Actual

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
Genetic Carriers and Non-Carriers of PKU	Experimental		Dietary Supplement: L-Phenylalanine

Interventions

Name	Type	Description	Arm Group Labels	Other Names
L-Phenylalanine	Dietary Supplement	100 mg/kg	Genetic Carriers and Non-Carriers of PKU

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Stop Signal Reaction Time	Response Inhibition	Change from baseline to 2-hours post L-Phe supplementation

Secondary Outcomes

Measure	Description	Time Frame
Working Memory	N-Back Test Outcome	Change from baseline to 2-hours post L-Phe supplementation
Individual Coefficient of Variance (Variability in Reaction Time)	Stop Signal Task Outcome

Other Outcomes

Measure	Description	Time Frame
Chronic Anxiety	GAD-7 Outcome (higher scores indicate worse anxiety: range of 0 to >15)	Baseline
Chronic Depression	PHQ-9 Outcome (higher scores indicate worse depression: range of 0 to 27)

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

Carrier or non-carrier of PKU
At least 18 Years of age
Comfortable fasting the morning of the study (no food or drink other than water)

Exclusion Criteria:

Diagnosed with: PKU, severe neurodegenerative conditions affecting cognition (e.g. Alzheimer's, Parkinson's, dementia), melanoma, hypertension, liver disease and/or kidney disease
Diagnosed with hypertension or hypotension
Taking a monoamine oxidase inhibitor anti-depressant
Pregnant or breastfeeding
Orange/citrus allergy or intolerance
Body weight 150 kg or greater
History of fainting during blood sampling

Accepts Healthy Volunteers

Yes

Sex

All

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

18 Years

Maximum Age

Not provided

Standard Ages

AdultOlder Adult

Study Population

Not provided

Sampling Method

Not provided

Contacts/Locations Module

Central Contacts

Not provided

Overall Officials

Not provided

Locations

Facility	Status	City	State	ZIP	Country	Contacts
University of Guelph		Guelph	Ontario	N1G 2W1	Canada

References Module

Citations

PubMed Identifier	Type	Citation	Retractions
41555437	Derived	Khan SM, Fennell ML, Fallah M, Jordan H, Kroezen Z, Britz-McKibbin P, Millar PJ, Heister RR, Vohl MC, Keathley JR. Study protocol and pilot study results for a clinical intervention trial of PKU carriers and non-carriers: the Phe for Me trial. Orphanet J Rare Dis. 2026 Jan 19;21(1):18. doi: 10.1186/s13023-025-04131-2.

ID	Term
D024322	Amino Acids, Aromatic
D000598	Amino Acids, Cyclic
D000596	Amino Acids
D000602	Amino Acids, Peptides, and Proteins