protocolSection identificationModule nctId: NCT06337864, orgStudyIdInfo id: H-24017055, briefTitle: Evaluating the Efficacy and Safety of Large Neutral Amino Acids in the Treatment of Classical Phenylketonuria, statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-05, primaryCompletionDateStruct date: 2026-12, completionDateStruct date: 2027-12, studyFirstPostDateStruct date: 2024-03-29, lastUpdatePostDateStruct date: 2024-03-29, sponsorCollaboratorsModule leadSponsor name: Rigshospitalet, Denmark, class: OTHER, descriptionModule briefSummary: This research investigates the effectiveness and safety of large neutral amino acid (LNAA) supplementation in patients with classical phenylketonuria (PKU). Advanced brain imaging techniques alongside comprehensive neuropsychological and functional assessments will be employed. Short-term and long-term follow-up of participants will be conducted., conditionsModule conditions: Brain Diseases, conditions: Brain Diseases, Metabolic, conditions: Brain Diseases, Metabolic, Inborn, conditions: Genetic Diseases, Inborn, conditions: Metabolism, Inborn Errors, conditions: Amino Acid Metabolism, Inborn Errors, conditions: Metabolic Disease, conditions: Phenylketonurias, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: RANDOMIZED, interventionModel: CROSSOVER, interventionModelDescription: To fully assess the effectiveness of LNAA, the following trials will be conducted:1. A crossover study comparing LNAA supplementation to no treatment2. A crossover study comparing LNAA supplementation to the Phe-free PKU diet3. Open-label extension study to assess the long-term safety and efficacy of LNAA supplementation4. Healthy control group, primaryPurpose: TREATMENT, maskingInfo masking: NONE, enrollmentInfo count: 30, type: ESTIMATED, armsInterventionsModule interventions name: PreKUnil® LNAA Medical Food for PKU, outcomesModule primaryOutcomes measure: Dynamic positron emission tomography (PET) imaging with the fluorine-18-labeled tracer [18F]-(E)-N-(3-iodoprop-2-enyl)-2β-carbofluoroethoxy-3β-(4'-methyl phenyl)nortropane ([18F]FE-PE2I), primaryOutcomes measure: Computerized neuropsychological testing (responses over study iPad), secondaryOutcomes measure: Behaviour Rating Inventory of Executive Function - Adult version (BRIEF-A), secondaryOutcomes measure: Behaviour Rating Inventory of Executive Function - Second edition (BRIEF-2), secondaryOutcomes measure: Adult attention deficit hyperactivity disorder (ADHD) Self-Report Scale (ASRS v1.1), secondaryOutcomes measure: Adolescent ADHD Self-Report Scale, secondaryOutcomes measure: PKU-QOL Questionnaire Adolescent or Adult version, secondaryOutcomes measure: Symptom Checklist-90-Revised (SCL-90-R), secondaryOutcomes measure: Behavior Assessment System for Children, Third Edition (BASC-3), secondaryOutcomes measure: Neuropsychological testing of flexibility and verbal fluency, secondaryOutcomes measure: Urine peripheral biomarkers of neurotransmitters, secondaryOutcomes measure: Incidence and severity of treatment-emergent adverse events (TEAEs), otherOutcomes measure: Fasting plasma amino acids, dried blood spots (finger-prick method), otherOutcomes measure: Brain perfusion measures, otherOutcomes measure: Adherence to dietary treatment, otherOutcomes measure: Brain Magnetic Resonance Imaging (MRI), otherOutcomes measure: Wechsler Adult Intelligence Scale (WAIS) - IV, eligibilityModule sex: ALL, minimumAge: 16 Years, maximumAge: 50 Years, stdAges: CHILD, stdAges: ADULT, contactsLocationsModule locations facility: Copenhagen University Hospital, Rigshospitalet, city: Copenhagen, country: Denmark, contacts name: Olivia Welle Fjellbirkeland, MD, role: CONTACT, email: olivia.welle.fjellbirkeland@regionh.dk, geoPoint lat: 55.67594, lon: 12.56553, hasResults: False