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ClinicalTrials.gov public records Last synced Oct 19, 2026, 11:30 AM EDT

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Showing 1–24 of 61 matching trials from the live ClinicalTrials.gov search.
Filters: Intervention: BH4 Clear all
Completed Phase 1Phase 2 Interventional Results available

Kuvan in People With Schizophrenia and Schizoaffective Disorder

NCT01706965
View directory record Official record
Conditions
Schizophrenia, Schizoaffective Disorder
Interventions
Kuvan, Multivitamin
Drug
Lead sponsor
New York State Psychiatric Institute
Other
Eligibility
18 Years to 64 Years
Enrollment
27 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2012 – 2016
U.S. locations
1
States / cities
New York, New York
Source: ClinicalTrials.gov public record
Updated Sep 13, 2017 · Synced Oct 19, 2026, 11:30 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 19, 2026, 11:30 AM EDT
Completed Phase 1Phase 2 Interventional Accepts healthy volunteers Results available

Systemic Sclerosis (SSc) Vasculopathy: Improved Clinical Monitoring and Treatment

NCT02530996
View directory record Official record
Conditions
Rheumatologic Disease
Interventions
BH4, Vasculopathy assessment, Placebo
Drug · Diagnostic Test
Lead sponsor
VA Office of Research and Development
Federal
Eligibility
18 Years to 95 Years
Enrollment
12 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2016 – 2019
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Apr 5, 2021 · Synced Oct 19, 2026, 11:30 AM 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 19, 2026, 11:30 AM EDT
Terminated Phase 2 Interventional Results available

Oral 6R-BH4 for the Treatment of Isolated Systolic Hypertension and Endothelial Dysfunction

NCT00802893
View directory record Official record
Conditions
Isolated Systolic Hypertension, Endothelial Dysfunction
Interventions
6R-BH4, Placebo
Drug · Other
Lead sponsor
Johns Hopkins University
Other
Eligibility
40 Years and older
Enrollment
3 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2008 – 2009
U.S. locations
1
States / cities
Baltimore, Maryland
Source: ClinicalTrials.gov public record
Updated Aug 21, 2017 · Synced Oct 19, 2026, 11:30 AM EDT
Completed Phase 3 Interventional

A Phase 3, Multicenter, Open-Label Extension Study of Phenoptin in Subjects With PKU Who Have Elevated Phenylalanine Levels

NCT00225615
View directory record Official record
Conditions
Phenylketonurias
Interventions
sapropterin dihydrochloride
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
8 Years and older
Enrollment
100 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2005 – 2006
U.S. locations
14
States / cities
Los Angeles, California • Oakland, California • Sacramento, California + 11 more
Source: ClinicalTrials.gov public record
Updated Aug 20, 2009 · Synced Oct 19, 2026, 11:30 AM EDT
Completed Not applicable Interventional Accepts healthy volunteers Results available

Nitric Oxide Bioavailability in Chronic Obstructive Pulmonary Disease (COPD)

NCT01398943
View directory record Official record
Conditions
Pulmonary Disease, Chronic Obstructive
Interventions
Tetrahydrobiopterin (BH4), Antioxidant Cocktail
Drug · Dietary Supplement
Lead sponsor
Augusta University
Other
Eligibility
18 Years and older
Enrollment
60 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2010 – 2015
U.S. locations
1
States / cities
Augusta, Georgia
Source: ClinicalTrials.gov public record
Updated Dec 11, 2017 · Synced Oct 19, 2026, 11:30 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 19, 2026, 11:30 AM 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 19, 2026, 11:30 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 19, 2026, 11:30 AM EDT
Completed Phase 1Phase 2 Interventional Results available

Study of Kuvan Treatment in Adults With GTPCH Deficiency

NCT01425528
View directory record Official record
Conditions
GTP Cyclohydrolase Deficiency
Interventions
Sapropterin
Drug
Lead sponsor
University of Utah
Other
Eligibility
18 Years and older
Enrollment
12 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2011 – 2013
U.S. locations
1
States / cities
Salt Lake City, Utah
Source: ClinicalTrials.gov public record
Updated Apr 1, 2025 · Synced Oct 19, 2026, 11:30 AM EDT
Completed No phase listed Observational Accepts healthy volunteers

Determination of Variances in Exhaled Nitric Oxide Output in Normal Healthy Male Volunteers Consuming High and Low Nitrate/Nitrite Diets

NCT00027157
View directory record Official record
Conditions
Healthy
Interventions
Not listed
Lead sponsor
National Heart, Lung, and Blood Institute (NHLBI)
NIH
Eligibility
Male only
Enrollment
18 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2000 – 2003
U.S. locations
1
States / cities
Bethesda, Maryland
Source: ClinicalTrials.gov public record
Updated Mar 4, 2008 · Synced Oct 19, 2026, 11:30 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 19, 2026, 11:30 AM EDT
Completed Phase 2 Interventional

A Study of the Effects of 6R-BH4 on Blood Pressure in Subjects With Poorly Controlled Systemic Hypertension

NCT00325962
View directory record Official record
Conditions
Hypertension
Interventions
6R-BH4 (sapropterin dihydrochloride)
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
18 Years and older
Enrollment
84 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2006 – 2008
U.S. locations
24
States / cities
Hoover, Alabama • Huntsville, Alabama • Mobile, Alabama + 21 more
Source: ClinicalTrials.gov public record
Updated Jul 21, 2009 · Synced Oct 19, 2026, 11:30 AM EDT
Completed Phase 2 Interventional Results available

Tetrahydrobiopterin in Patients With Chronic Kidney Disease (CKD) and Albuminuria

NCT00625820
View directory record Official record
Conditions
Kidney Disease, Albuminuria
Interventions
6R BH4, Vitamin C
Drug · Dietary Supplement
Lead sponsor
University of Michigan
Other
Eligibility
18 Years to 75 Years
Enrollment
17 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2008
U.S. locations
1
States / cities
Ann Arbor, Michigan
Source: ClinicalTrials.gov public record
Updated Oct 18, 2016 · Synced Oct 19, 2026, 11:30 AM EDT
Completed Early Phase 1 Interventional Accepts healthy volunteers

Sex Hormones and Atherosclerosis Prevention in Perimenopausal Women

NCT02042196
View directory record Official record
Conditions
Menopause, Aging
Interventions
KUVAN, Placebo, Cetrotide, Climara, Placebo transdermal patch
Drug
Lead sponsor
University of Colorado, Denver
Other
Eligibility
18 Years to 70 Years · Female only
Enrollment
100 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2013 – 2016
U.S. locations
1
States / cities
Aurora, Colorado
Source: ClinicalTrials.gov public record
Updated Jul 11, 2019 · Synced Oct 19, 2026, 11:30 AM EDT
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 19, 2026, 11:30 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 19, 2026, 11:30 AM 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 19, 2026, 11:30 AM EDT
Completed No phase listed Observational

PKUDOS: Phenylketonuria (PKU) Demographic, Outcomes, and Safety Registry

NCT00778206
View directory record Official record
Conditions
Phenylketonuria, Hyperphenylalaninaemia
Interventions
Kuvan
Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
Not listed
Enrollment
1,887 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2008 – 2021
U.S. locations
45
States / cities
Los Angeles, California • Orange, California • San Diego, California + 38 more
Source: ClinicalTrials.gov public record
Updated Oct 12, 2022 · Synced Oct 19, 2026, 11:30 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 19, 2026, 11:30 AM EDT
Completed No phase listed Observational Accepts healthy volunteers

PKU Skin Stripping

NCT04368624
View directory record Official record
Conditions
Phenylketonurias
Interventions
Skin Tape, Blood Draw
Other · Diagnostic Test
Lead sponsor
Children's Hospital Medical Center, Cincinnati
Other
Eligibility
Not listed
Enrollment
86 participants
Healthy volunteers
Accepts healthy volunteers
Timeline
2015 – 2021
U.S. locations
1
States / cities
Cincinnati, Ohio
Source: ClinicalTrials.gov public record
Updated Jul 28, 2021 · Synced Oct 19, 2026, 11:30 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 19, 2026, 11:30 AM EDT
Completed Phase 2 Interventional Results available

A Phase 2 Study of the Effects of Sapropterin Dihydrochloride on Symptomatic Peripheral Arterial Disease

NCT00403494
View directory record Official record
Conditions
Intermittent Claudication
Interventions
Placebo, Sapropterin Dihydrochloride
Other · Drug
Lead sponsor
BioMarin Pharmaceutical
Industry
Eligibility
40 Years to 80 Years
Enrollment
190 participants
Healthy volunteers
Healthy volunteers not accepted
Timeline
2006 – 2009
U.S. locations
17
States / cities
Scottsdale, Arizona • Sacramento, California • San Diego, California + 14 more
Source: ClinicalTrials.gov public record
Updated Jan 7, 2021 · Synced Oct 19, 2026, 11:30 AM EDT