A Phase 1 interventional study of Tetrahydrobiopterin 10 mg/kg and Tetrahydrobiopterin 20 mg/kg in Claudication, Intermittent, Peripheral Artery Disease and Peripheral Vascular Diseases, sponsored by Louis Messina. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-15.
Sponsored by Louis Messina · Phase 1, Interventional, and Other
This study will focus on people with claudication from peripheral arterial disease. The investigators are researching whether a multicomponent therapeutic can increase the production of Nitric Oxide in the blood and whether that leads to an improvement in pain free walking distance and overall physical activity.
The primary objective of this study is to show that ATLAS Therapy, (L-Arginine; Tetrahydrobiopterin; L-Ascorbate) is bioavailable in humans and exerts a measurable effect on its in vivo biological signature, Flow Mediated Vasodilation (FMD) in people with intermittent claudication caused by peripheral arterial disease. This will be a Phase I / dose finding study. All subjects will receive 2 different drug doses of the Kuvan the first 45 days they will receive 10 mg/kg/day. The second 45 days they will receive 20/mg/kg/day.
309 studies on the registry are indexed under Intermittent Claudication; 46 are open to participants now.
This study's planned enrollment of 10 is below the median of 74 across 242 interventional studies indexed under Intermittent Claudication.
Browse Intermittent Claudication studies →This is the only study on the registry with Louis Messina as lead sponsor.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All subjects will receive 3300mg l-Ascorbate , l-Arginine 3400mg and 10mg/kg of Tetrahydrobiopterin once a day.
Drug: Tetrahydrobiopterin 10 mg/kg · Drug: L-Ascorbate · Drug: L-Arginine
All subjects will receive 3300mg l-Ascorbate, l-Arginine 3400mg and 20mg/kg of Tetrahydrobiopterin once a day.
Drug: Tetrahydrobiopterin 20 mg/kg · Drug: L-Ascorbate · Drug: L-Arginine
Drug page: Sapropterin
10mg/kg of Tetrahydrobiopterin daily.
Also known as: sapropterin, kuvan
Drug page: Sapropterin
20mg/kg of Tetrahydrobiopterin daily.
Also known as: sapropterin, kuvan
3300 mg of l-ascorbate once daily
3400mg of l-arginine once daily
Nitric Oxide bioavailability
Nitric Oxide bioavailability as measured by flow mediated dilatation (FMD).
Time frame: 90 days
Plan to share: No
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Sapropterin