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ClinicalTrials.gov public records Last synced Oct 4, 2026, 6:53 AM EDT

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Showing 1–22 of 22 matching trials from the live ClinicalTrials.gov search.
Filters: Intervention: Tetrahydrobiopterin 20 mg/kg Clear all
Completed Phase 1 Interventional

6R-BH4 Pulmonary Arterial Hypertension Study

NCT00435331
View directory record Official record
Conditions
Pulmonary Arterial Hypertension
Interventions
sapropterin dihydrochloride (6R-BH4)
Drug
Lead sponsor
Vanderbilt University
Other
Eligibility
18 Years and older
Enrollment
14 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2008
U.S. locations
1
States / cities
Nashville, Tennessee
Source: ClinicalTrials.gov public record
Updated Jun 19, 2013 · Synced Oct 4, 2026, 6:53 AM EDT
Withdrawn Not applicable Interventional

Neuroimaging and Neurocognitive Assessment and Response to Sapropterin Dihydrochloride Treatment in Phenylketonuria

NCT01412437
View directory record Official record
Conditions
PKU
Interventions
diet, sapropterin dihydrochloride
Dietary Supplement · Drug
Lead sponsor
Children's National Research Institute
Other
Eligibility
18 Years to 40 Years
Healthy volunteers
Healthy volunteers not accepted
Timeline
2011 – 2012
U.S. locations
1
States / cities
Washington D.C., District of Columbia
Source: ClinicalTrials.gov public record
Updated Dec 17, 2014 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Results available

Endothelial Facilitation in Alzheimer's Disease

NCT01439555
View directory record Official record
Conditions
Alzheimer's Disease
Interventions
Simvastatin, L-Arginine, Tetrahydrobiopterin
Drug
Lead sponsor
University of Massachusetts, Worcester
Other
Eligibility
55 Years to 85 Years
Enrollment
11 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2011 – 2017
U.S. locations
1
States / cities
Worcester, Massachusetts
Source: ClinicalTrials.gov public record
Updated Jul 30, 2019 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 4 Interventional Results available

Effects of Kuvan on Melatonin Secretion

NCT01617070
View directory record Official record
Conditions
Phenylketonuria (PKU)
Interventions
Kuvan, Large Neutral Amino Acid Therapy
Drug · Dietary Supplement
Lead sponsor
University of Southern California
Other
Eligibility
18 Years and older
Enrollment
10 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2012 – 2014
U.S. locations
1
States / cities
Los Angeles, California
Source: ClinicalTrials.gov public record
Updated Nov 18, 2016 · Synced Oct 4, 2026, 6:53 AM EDT
Terminated No phase listed Observational

Behavioral Effects of Kuvan in Children With Mild Phenylketonuria

NCT00827762
View directory record Official record
Conditions
Phenylketonuria
Interventions
Kuvan
Drug
Lead sponsor
Washington University School of Medicine
Other
Eligibility
6 Years to 18 Years
Enrollment
2 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2009 – 2010
U.S. locations
4
States / cities
Chicago, Illinois • Columbia, Missouri • St Louis, Missouri + 1 more
Source: ClinicalTrials.gov public record
Updated Dec 5, 2013 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Accepts healthy volunteers Results available

Cystic Fibrosis and Endothelial Function: At Rest and During Exercise

NCT01772758
View directory record Official record
Conditions
Cystic Fibrosis
Interventions
BH4 5mg, BH4 20mg, Antioxidant Cocktail
Drug · Dietary Supplement
Lead sponsor
Augusta University
Other
Eligibility
7 Years and older
Enrollment
64 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2011 – 2016
U.S. locations
1
States / cities
Augusta, Georgia
Source: ClinicalTrials.gov public record
Updated Jun 20, 2019 · Synced Oct 4, 2026, 6:53 AM EDT
Terminated Not applicable Interventional Accepts healthy volunteers Results available

Bone Mineral Density in Adults With Hyperphenylalaninemia on Kuvan Therapy

NCT01541397
View directory record Official record
Conditions
Hyperphenylalaninemia, Phenylketonuria
Interventions
Sapropterin
Drug
Lead sponsor
The University of Texas Health Science Center, Houston
Other
Eligibility
18 Years to 50 Years
Enrollment
6 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2011 – 2012
U.S. locations
1
States / cities
Houston, Texas
Source: ClinicalTrials.gov public record
Updated Jul 7, 2015 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Not applicable Interventional Results available

Fluorodeoxyglucose Positron Emission Tomography (FDG PET) Findings in Patients With Phenylketonuria Before and After KUVAN Therapy

NCT00986973
View directory record Official record
Conditions
Phenylketonuria
Interventions
Sapropterin
Drug
Lead sponsor
Children's Hospital of Philadelphia
Other
Eligibility
18 Years to 50 Years
Enrollment
6 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2010 – 2011
U.S. locations
1
States / cities
Philadelphia, Pennsylvania
Source: ClinicalTrials.gov public record
Updated Jun 8, 2015 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Results available

A Phase 2 Study of the Effects of 6R-BH4 in Subjects With Sickle Cell Disease

NCT00445978
View directory record Official record
Conditions
Sickle Cell Disease
Interventions
Sapropterin Dihydrochloride
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
15 Years and older
Enrollment
32 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2007 – 2009
U.S. locations
12
States / cities
Washington D.C., District of Columbia • Augusta, Georgia • Savannah, Georgia + 9 more
Source: ClinicalTrials.gov public record
Updated Feb 25, 2021 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 3 Interventional Results available

Safety and Therapeutic Effects of Sapropterin Dihydrochloride on Neuropsychiatric Symptoms in Phenylketonuria (PKU) Patients

NCT01114737
View directory record Official record
Conditions
Phenylketonuria
Interventions
Sapropterin dihydrochloride, Placebo
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
8 Years to 65 Years
Enrollment
206 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2010 – 2013
U.S. locations
26
States / cities
La Jolla, California • Los Angeles, California • Palo Alto, California + 23 more
Source: ClinicalTrials.gov public record
Updated Feb 1, 2016 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 1 Interventional Accepts healthy volunteers

A Phase 1 Study to Evaluate Effects of Sapropterin Dihydrochloride on QTc Intervals in Healthy Adult Subjects

NCT00789568
View directory record Official record
Conditions
Phenylketonuria
Interventions
sapropterin dihydrochloride, Moxifloxacin, Moxifloxacin placebo
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
18 Years to 50 Years
Enrollment
56 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2008 – 2009
U.S. locations
1
States / cities
Fargo, North Dakota
Source: ClinicalTrials.gov public record
Updated Jul 23, 2021 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2Phase 3 Interventional Results available

Open-Label Extension Study of Kuvan for Autism

NCT00943579
View directory record Official record
Conditions
Autistic Disorder
Interventions
Kuvan®
Drug
Lead sponsor
The Children's Health Council
Other
Eligibility
3 Years to 6 Years
Enrollment
41 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2009 – 2012
U.S. locations
1
States / cities
Palo Alto, California
Source: ClinicalTrials.gov public record
Updated May 2, 2018 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Results available

Sapropterin as a Treatment for Autistic Disorder

NCT00850070
View directory record Official record
Conditions
Autistic Disorder
Interventions
sapropterin, Placebo
Drug
Lead sponsor
The Children's Health Council
Other
Eligibility
3 Years to 6 Years
Enrollment
46 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2009 – 2011
U.S. locations
1
States / cities
Palo Alto, California
Source: ClinicalTrials.gov public record
Updated May 1, 2018 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Results available

Kuvan Therapy in Phenylketonuria (PKU): The Effect of Blood Phenylalanine Concentration on Kuvan Response

NCT00841100
View directory record Official record
Conditions
Phenylketonuria
Interventions
Kuvan, Diet
Drug · Other
Lead sponsor
University of Miami
Other
Eligibility
4 Years and older
Enrollment
21 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2008 – 2011
U.S. locations
1
States / cities
Miami, Florida
Source: ClinicalTrials.gov public record
Updated Dec 3, 2019 · Synced Oct 4, 2026, 6:53 AM EDT
Recruiting Phase 1 Interventional

Novel Approaches for Improving Vascular Function in Veterans With HFpEF

NCT06312748
View directory record Official record
Conditions
Heart Failure With Preserved Ejection Fraction, Inflammation
Interventions
L-Citrulline, Placebo for L-Citrulline, BH4, Placebo for BH4, Atorvastatin, Placebo for Atorvastatin
Drug
Lead sponsor
VA Office of Research and Development
Federal
Eligibility
18 Years and older
Enrollment
90 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2021 – 2030
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Apr 23, 2026 · Synced Oct 4, 2026, 6:53 AM EDT
Terminated Not applicable Interventional Accepts healthy volunteers Results available

A Pilot Study on Diurnal Variation

NCT01806051
View directory record Official record
Conditions
Phenylketonuria (PKU)
Interventions
Kuvan
Drug
Lead sponsor
Dr. Linda Randolph
Other
Eligibility
4 Years and older
Enrollment
6 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2013 – 2014
U.S. locations
1
States / cities
Los Angeles, California
Source: ClinicalTrials.gov public record
Updated Apr 20, 2016 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 2 Interventional Results available

Safety and Efficacy Study of Phenoptin in Subjects With Hyperphenylalaninemia Due to BH4 Deficiency

NCT00355264
View directory record Official record
Conditions
Tetrahydrobiopterin Deficiencies, Hyperphenylalaninemia, Non-Phenylketonuric
Interventions
Phenoptin
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
Not listed
Enrollment
12 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2006 – 2009
U.S. locations
9
States / cities
Los Angeles, California • Chicago, Illinois • Minneapolis, Minnesota + 6 more
Source: ClinicalTrials.gov public record
Updated Sep 25, 2020 · Synced Oct 4, 2026, 6:53 AM EDT
Active, not recruiting Phase 1 Interventional

The Effects of ATLAS Therapy on Nitric Oxide Bioavailability in Patients With Intermittent Claudication

NCT04800692
View directory record Official record
Conditions
Claudication, Intermittent, Peripheral Artery Disease, Peripheral Vascular Diseases
Interventions
Tetrahydrobiopterin 10 mg/kg, Tetrahydrobiopterin 20 mg/kg, L-Ascorbate, L-Arginine
Drug
Lead sponsor
Louis Messina
Other
Eligibility
18 Years and older
Enrollment
10 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2021 – 2027
U.S. locations
1
States / cities
Worcester, Massachusetts
Source: ClinicalTrials.gov public record
Updated Apr 15, 2026 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Not applicable Interventional Results available

Tetrahydrobiopterin Treatment in Children With Idiopathic Cognitive Developmental Disorders

NCT01141595
View directory record Official record
Conditions
Autism Spectrum Disorder
Interventions
sapropterin dihydrochloride
Drug
Lead sponsor
The University of Texas Health Science Center, Houston
Other
Eligibility
2 Years to 6 Years
Enrollment
10 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2010 – 2011
U.S. locations
1
States / cities
Little Rock, Arkansas
Source: ClinicalTrials.gov public record
Updated Apr 1, 2014 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 1Phase 2 Interventional Results available

A Study of PTC923 (CNSA-001) in Primary Tetrahydrobiopterin (BH4) Deficient Participants With Hyperphenylalaninemia

NCT03519711
View directory record Official record
Conditions
BH4 Deficiency, Hyperphenylalaninemia
Interventions
PTC923
Drug
Lead sponsor
PTC Therapeutics
Industry
Eligibility
12 Months and older
Enrollment
8 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2019 – 2020
U.S. locations
4
States / cities
Minneapolis, Minnesota • Dallas, Texas • Salt Lake City, Utah + 1 more
Source: ClinicalTrials.gov public record
Updated Nov 14, 2023 · Synced Oct 4, 2026, 6:53 AM EDT
Terminated Phase 2 Interventional Accepts healthy volunteers Results available

Phenylketonuria, Oxidative Stress, and BH4

NCT01395394
View directory record Official record
Conditions
Phenylketonuria
Interventions
Kuvan, Meal Challenge
Drug · Other
Lead sponsor
Emory University
Other
Eligibility
10 Years to 45 Years
Enrollment
12 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2011 – 2013
U.S. locations
1
States / cities
Decatur, Georgia
Source: ClinicalTrials.gov public record
Updated Aug 28, 2014 · Synced Oct 4, 2026, 6:53 AM EDT
Completed Phase 3 Interventional Results available

Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU

NCT00838435
View directory record Official record
Conditions
Phenylketonuria
Interventions
sapropterin dihydrochloride
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
Up to 6 Years
Enrollment
95 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2009 – 2018
U.S. locations
12
States / cities
La Jolla, California • Orange, California • Tampa, Florida + 9 more
Source: ClinicalTrials.gov public record
Updated Dec 22, 2020 · Synced Oct 4, 2026, 6:53 AM EDT