Independent directory Public ClinicalTrials.gov records United States
Clinical Trials Finder
Objective public record navigation
Search Results

Search by objective public record fields.

Search by query text, NCT ID, condition, intervention, sponsor, city, state, recruitment status, phase, study type, healthy volunteer eligibility, sex, or age. Results come from ClinicalTrials.gov. When the live registry is unavailable, a clearly labeled stored copy may be shown.

Clear filters

These results were retrieved from the live ClinicalTrials.gov registry. Filters and sort order apply to this result list.

ClinicalTrials.gov public records Last synced Oct 8, 2026, 5:18 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Showing 25–48 of 61 matching trials from the live ClinicalTrials.gov search.
Filters: Intervention: tetrahydrobiopterin (BH4) Clear all
Completed No phase listed Observational Accepts healthy volunteers

Sapropterin in Individuals With Phenylketonuria

NCT00730080
View directory record Official record
Conditions
Phenylketonuria
Interventions
Sapropterin (Kuvan)
Drug
Lead sponsor
Washington University School of Medicine
Other
Eligibility
6 Years to 50 Years
Enrollment
45 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2008 – 2018
U.S. locations
1
States / cities
St Louis, Missouri
Source: ClinicalTrials.gov public record
Updated Jun 18, 2018 · Synced Oct 8, 2026, 5:18 PM EDT
Completed No phase listed Observational Accepts healthy volunteers

The Effects of Kuvan on Functional Brain Connectivity in Individuals With Phenylketonuria (PKU)

NCT00964236
View directory record Official record
Conditions
Phenylketonuria
Interventions
Sapropterin
Drug
Lead sponsor
University of Missouri-Columbia
Other
Eligibility
6 Years and older
Enrollment
20 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2009 – 2011
U.S. locations
1
States / cities
Columbia, Missouri
Source: ClinicalTrials.gov public record
Updated Jan 4, 2018 · Synced Oct 8, 2026, 5:18 PM EDT
Terminated Phase 1 Interventional Accepts healthy volunteers

Response to Phenylketonuria to Tetrahydrobiopterin (BH4)

NCT00244218
View directory record Official record
Conditions
Phenylketonuria
Interventions
tetrahydrobiopterin (BH4)
Drug
Lead sponsor
The University of Texas Medical Branch, Galveston
Other
Eligibility
10 Years and older
Enrollment
57 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2005 – 2015
U.S. locations
1
States / cities
Galveston, Texas
Source: ClinicalTrials.gov public record
Updated Sep 21, 2021 · Synced Oct 8, 2026, 5:18 PM EDT
Completed Phase 2 Interventional Results available

A Phase 2, Pharmacokinetic (PK) Study of 6R-BH4 Alone or 6R-BH4 With Vitamin C in Subjects With Endothelial Dysfunction

NCT00532844
View directory record Official record
Conditions
Endothelial Dysfunction
Interventions
Sapropterin Dihydrochloride, Sapropterin Dihydrochloride and Vitamin C
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
18 Years to 75 Years
Enrollment
52 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2007 – 2009
U.S. locations
1
States / cities
Hackensack, New Jersey
Source: ClinicalTrials.gov public record
Updated May 17, 2021 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed Early Phase 1 Interventional

Effects of Tetrahydrobiopterin on Blood Pressure

NCT00208780
View directory record Official record
Conditions
Hypertension
Interventions
Tetrahydrobiopterin
Drug
Lead sponsor
Emory University
Other
Eligibility
18 Years to 75 Years
Enrollment
24 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2004 – 2005
U.S. locations
1
States / cities
Atlanta, Georgia
Source: ClinicalTrials.gov public record
Updated Nov 18, 2013 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed Phase 2 Interventional Accepts healthy volunteers Results available

Exercise Intolerance in Renal Failure

NCT01356966
View directory record Official record
Conditions
Kidney Failure, Chronic
Interventions
Tetrahydrobiopterin, Placebo, Folate
Drug · Dietary Supplement
Lead sponsor
Emory University
Other
Eligibility
18 Years to 75 Years
Enrollment
74 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2011 – 2014
U.S. locations
2
States / cities
Atlanta, Georgia • Decatur, Georgia
Source: ClinicalTrials.gov public record
Updated Jun 1, 2015 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed Phase 3 Interventional Results available

Study of Phenoptin in Subjects With Phenylketonuria Who Participated in Protocols PKU-004 or PKU-006

NCT00332189
View directory record Official record
Conditions
Phenylketonuria
Interventions
sapropterin dihydrochloride
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
4 Years and older
Enrollment
111 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2006 – 2009
U.S. locations
14
States / cities
Los Angeles, California • Sacramento, California • San Jose, California + 11 more
Source: ClinicalTrials.gov public record
Updated Nov 16, 2012 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed Early Phase 1 Interventional

Exercise and NO in HFrEF

NCT03136029
View directory record Official record
Conditions
Heart Failure With Reduced Ejection Fraction
Interventions
Antioxidant, Tetrahydrobiopterin (BH4), Exercise training
Dietary Supplement · Other
Lead sponsor
VA Office of Research and Development
Federal
Eligibility
18 Years and older
Enrollment
68 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2018 – 2025
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Aug 6, 2025 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed No phase listed Observational Accepts healthy volunteers

Evaluation of Behavior, Executive Function, Neurotransmitter Function and Genomic Expression Kuvan Nonresponders

NCT01274026
View directory record Official record
Conditions
Phenylketonuria, Behavior and Behavior Mechanisms, PAH Gene Expression
Interventions
sapropterin dihydrochloride
Drug
Lead sponsor
Tulane University School of Medicine
Other
Eligibility
2 Years to 21 Years
Enrollment
21 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2011 – 2013
U.S. locations
1
States / cities
New Orleans, Louisiana
Source: ClinicalTrials.gov public record
Updated Aug 14, 2023 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT
Completed Not applicable Interventional Results available

Rhode Island Diastolic Dysfunction - Heart Failure

NCT02353312
View directory record Official record
Conditions
Heart Failure, Cardiovascular Disease
Interventions
Kuvan
Drug
Lead sponsor
Providence VA Medical Center
Federal
Eligibility
18 Years and older
Enrollment
28 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2015 – 2018
U.S. locations
1
States / cities
Providence, Rhode Island
Source: ClinicalTrials.gov public record
Updated Jul 3, 2025 · Synced Oct 8, 2026, 5:18 PM EDT
Completed Phase 3 Interventional Results available

Study of Phenoptin to Increase Phenylalanine Tolerance in Phenylketonuric Children on a Phenylalanine-restricted Diet

NCT00272792
View directory record Official record
Conditions
Phenylketonurias
Interventions
Sapropterin Dihydrochloride, Placebo
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
4 Years to 12 Years
Enrollment
45 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2006
U.S. locations
9
States / cities
Los Angeles, California • Oakland, California • Sacramento, California + 6 more
Source: ClinicalTrials.gov public record
Updated Aug 13, 2015 · Synced Oct 8, 2026, 5:18 PM EDT
Recruiting Phase 1 Interventional Accepts healthy volunteers

: Vascular Function in Health and Disease

NCT02966665
View directory record Official record
Conditions
Chronic Obstructive Pulmonary Disease, Pulmonary Artery Hypertension, Heart Failure, Hypertension
Interventions
Maximum Exercise Tests, BH4, L-NMMA, Vitamin C, Vitamin E, α-Lipoic Acid and L-Ascorbate, BQ-123, Fexofenadine, Ranitidine, Angiotensin-II, Valsartan, Acetylcholine, Sodium Nitroprusside, Angiotensin-II, Norepinephrine, Phentolamine, BQ-123, MitoQ, BH4
Other · Drug
Lead sponsor
D. Walter Wray
Other
Eligibility
18 Years and older
Enrollment
420 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2008 – 2030
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Sep 25, 2026 · Synced Oct 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM 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 8, 2026, 5:18 PM EDT