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Effect of 6R-BH4 Treatment in Coronary Artery Disease (OXBIO Study)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00423280
Recruitment Status : Unknown
Verified June 2008 by University of Oxford.
Recruitment status was:  Recruiting
First Posted : January 18, 2007
Last Update Posted : August 7, 2008
Information provided by:

Study Description
Brief Summary:
The purpose of this study is to determine the effect of 6R-BH4 on vascular function in patients with coronary artery disease. We hypothesize that 6R-BH4 will improve vascular function in these patients.

Condition or disease Intervention/treatment Phase
Coronary Artery Disease Drug: 6R-BH4 Phase 2

Detailed Description:

Decreased production of nitric oxide (NO) from the endothelium (the layer of cells that forms the lining of all blood vessels) has been shown to contribute to atherosclerosis. NO has multiple beneficial effects on vascular function. Endothelial function can be measured in humans via a number of methods, and endothelial dysfunction has been shown to be a strong adverse predictor of cardiovascular events and mortality.

Tetrahydrobiopterin (BH4) is essential for the production of NO in endothelial cells. 6R-BH4 is a synthetic version of naturally occurring BH4. We aim to investigate the effects of oral 6R-BH4 supplementation on endothelial function in patients with coronary artery disease.

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 66 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Randomised, Placebo-Controlled Study of Two Doses of Oral 6R-BH4 on Vascular Function in Subjects With Coronary Artery Disease
Study Start Date : November 2006
Estimated Primary Completion Date : February 2009
Estimated Study Completion Date : February 2009

Resource links provided by the National Library of Medicine

Drug Information available for: Sapropterin
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Active Comparator: 1
700mg/day 6R-BH4
Drug: 6R-BH4
6R-BH4 tablets 700mg/day, 6R-BH4 tablets 400mg/day or placebo
Other Name: Sapropterin dihydrochloride
Active Comparator: 2
400mg/day 6R-BH4
Drug: 6R-BH4
6R-BH4 tablets 700mg/day, 6R-BH4 tablets 400mg/day or placebo
Other Name: Sapropterin dihydrochloride
Placebo Comparator: 3
Drug: 6R-BH4
6R-BH4 tablets 700mg/day, 6R-BH4 tablets 400mg/day or placebo
Other Name: Sapropterin dihydrochloride

Outcome Measures

Primary Outcome Measures :
  1. Vascular function using non-invasive magnetic resonance imaging (MRI). [ Time Frame: Pre- and post- treatment with 6R-BH4 or placebo ]

Secondary Outcome Measures :
  1. Laboratory measures of vascular function. [ Time Frame: At time of CABG surgery ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Multi-vessel coronary artery disease scheduled for coronary artery bypass surgery (CABG)

Exclusion Criteria:

  • Inability to provide informed consent
  • Female subject who is pregnant, lactating or planning pregnancy during course of study
  • Prior clinical diagnosis of heart failure requiring diuretic therapy with evidence of severe left ventricular dysfunction
  • Recent acute coronary event (<4 weeks)
  • Emergency CABG
  • Newly diagnosed diabetes mellitus (<1 month)
  • Body weight >130kg
  • Impaired renal function (creatinine >180umol/l)
  • Elevated liver function tests (ALT >50umol/l or AST >2x normal)
  • Pacemakers, ICDs or metallic implants not compatible with MRI scanning
  • Subjects receiving experimental medications or participating in another study
  • Terminally ill subjects
  • Known hypersensitivity to 6R-BH4
  • Concomitant treatment with methotrexate, levodopa, PDE-3 or PDE-5 inhibitors
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00423280

Contact: Colin Cunnington, MBChB MRCP +44-1865-221866 colin.cunnington@cardiov.ox.ac.uk

United Kingdom
Department of Cardiovascular Medicine, University of Oxford Recruiting
Oxford, United Kingdom, OX3 9DU
Sponsors and Collaborators
University of Oxford
BioMarin Pharmaceutical
Principal Investigator: Keith M Channon, MD FRCP University of Oxford
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Mrs Heather House, University of Oxford
ClinicalTrials.gov Identifier: NCT00423280     History of Changes
Other Study ID Numbers: 06/Q1604/114
First Posted: January 18, 2007    Key Record Dates
Last Update Posted: August 7, 2008
Last Verified: June 2008

Keywords provided by University of Oxford:
Nitric Oxide
Magnetic Resonance Imaging

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases