{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Tetrahydrobiopterin+%28BH4%29&page=2",
    "query": {
      "intervention": "Tetrahydrobiopterin (BH4)",
      "page": 2
    },
    "page_size": 10
  },
  "pagination": {
    "page": 2,
    "page_size": 10,
    "total_count": 61,
    "total_pages": 7,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Tetrahydrobiopterin+%28BH4%29&page=3&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Tetrahydrobiopterin+%28BH4%29&page=1&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-06T22:00:27.116Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT00225615",
      "title": "A Phase 3, Multicenter, Open-Label Extension Study of Phenoptin in Subjects With PKU Who Have Elevated Phenylalanine Levels",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Phenylketonurias"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "8 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "8 Years and older"
      },
      "enrollment_count": 100,
      "start_date": "2005-11",
      "completion_date": "2006-06",
      "has_results": false,
      "last_update_posted_date": "2009-08-20",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 14,
      "location_summary": "Los Angeles, California • Oakland, California • Sacramento, California + 11 more",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Oakland",
          "state": "California"
        },
        {
          "city": "Sacramento",
          "state": "California"
        },
        {
          "city": "San Jose",
          "state": "California"
        },
        {
          "city": "New Haven",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00225615"
    },
    {
      "nct_id": "NCT02774226",
      "title": "Long Term Nitric Oxide Bioavailability on Vascular Health in Chronic Obstructive Pulmonary Disease",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Chronic Obstructive Pulmonary Disease (COPD)"
      ],
      "interventions": [
        {
          "name": "Tetrahydrobiopterin (BH4)",
          "type": "DRUG"
        },
        {
          "name": "Antioxidant Cocktail",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Augusta University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 15,
      "start_date": "2015-09",
      "completion_date": "2018-07-30",
      "has_results": true,
      "last_update_posted_date": "2021-02-23",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Augusta, Georgia",
      "locations": [
        {
          "city": "Augusta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02774226"
    },
    {
      "nct_id": "NCT04368624",
      "title": "PKU Skin Stripping",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Phenylketonurias"
      ],
      "interventions": [
        {
          "name": "Skin Tape",
          "type": "OTHER"
        },
        {
          "name": "Blood Draw",
          "type": "DIAGNOSTIC_TEST"
        }
      ],
      "intervention_types": [
        "OTHER",
        "DIAGNOSTIC_TEST"
      ],
      "sponsor": "Children's Hospital Medical Center, Cincinnati",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "ALL",
        "summary": "Not listed"
      },
      "enrollment_count": 86,
      "start_date": "2015-10-12",
      "completion_date": "2021-04",
      "has_results": false,
      "last_update_posted_date": "2021-07-28",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Cincinnati, Ohio",
      "locations": [
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04368624"
    },
    {
      "nct_id": "NCT00244218",
      "title": "Response to Phenylketonuria to Tetrahydrobiopterin (BH4)",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "tetrahydrobiopterin (BH4)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "The University of Texas Medical Branch, Galveston",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "10 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "10 Years and older"
      },
      "enrollment_count": 57,
      "start_date": "2005-04",
      "completion_date": "2015-01",
      "has_results": false,
      "last_update_posted_date": "2021-09-21",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Galveston, Texas",
      "locations": [
        {
          "city": "Galveston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00244218"
    },
    {
      "nct_id": "NCT00838435",
      "title": "Effect of Kuvan on Neurocognitive Function, Blood Phenylalanine Level, Safety, and Pharmacokinetics in Children With PKU",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": "6 Years",
        "sex": "ALL",
        "summary": "Up to 6 Years"
      },
      "enrollment_count": 95,
      "start_date": "2009-02",
      "completion_date": "2018-09-14",
      "has_results": true,
      "last_update_posted_date": "2020-12-22",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 12,
      "location_summary": "La Jolla, California • Orange, California • Tampa, Florida + 9 more",
      "locations": [
        {
          "city": "La Jolla",
          "state": "California"
        },
        {
          "city": "Orange",
          "state": "California"
        },
        {
          "city": "Tampa",
          "state": "Florida"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00838435"
    },
    {
      "nct_id": "NCT02042196",
      "title": "Sex Hormones and Atherosclerosis Prevention in Perimenopausal Women",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Menopause",
        "Aging"
      ],
      "interventions": [
        {
          "name": "KUVAN",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Cetrotide",
          "type": "DRUG"
        },
        {
          "name": "Climara",
          "type": "DRUG"
        },
        {
          "name": "Placebo transdermal patch",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Colorado, Denver",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "70 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 70 Years · Female only"
      },
      "enrollment_count": 100,
      "start_date": "2013-12",
      "completion_date": "2016-05-02",
      "has_results": false,
      "last_update_posted_date": "2019-07-11",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Aurora, Colorado",
      "locations": [
        {
          "city": "Aurora",
          "state": "Colorado"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02042196"
    },
    {
      "nct_id": "NCT00484991",
      "title": "Sapropterin Expanded Access Program",
      "overall_status": "APPROVED_FOR_MARKETING",
      "study_type": "EXPANDED_ACCESS",
      "phases": [],
      "conditions": [
        "Phenylketonuria"
      ],
      "interventions": [
        {
          "name": "Sapropterin dihydrochloride",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": null,
      "eligibility": {
        "minimum_age": "9 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "9 Years and older"
      },
      "enrollment_count": null,
      "start_date": null,
      "completion_date": null,
      "has_results": false,
      "last_update_posted_date": "2008-04-15",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 36,
      "location_summary": "Los Angeles, California • Orange, California • San Diego, California + 33 more",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Orange",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Stanford",
          "state": "California"
        },
        {
          "city": "Denver",
          "state": "Colorado"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00484991"
    },
    {
      "nct_id": "NCT01439555",
      "title": "Endothelial Facilitation in Alzheimer's Disease",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Alzheimer's Disease"
      ],
      "interventions": [
        {
          "name": "Simvastatin",
          "type": "DRUG"
        },
        {
          "name": "L-Arginine",
          "type": "DRUG"
        },
        {
          "name": "Tetrahydrobiopterin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Massachusetts, Worcester",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "55 Years",
        "maximum_age": "85 Years",
        "sex": "ALL",
        "summary": "55 Years to 85 Years"
      },
      "enrollment_count": 11,
      "start_date": "2011-11",
      "completion_date": "2017-11",
      "has_results": true,
      "last_update_posted_date": "2019-07-30",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Worcester, Massachusetts",
      "locations": [
        {
          "city": "Worcester",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01439555"
    },
    {
      "nct_id": "NCT00325962",
      "title": "A Study of the Effects of 6R-BH4 on Blood Pressure in Subjects With Poorly Controlled Systemic Hypertension",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Hypertension"
      ],
      "interventions": [
        {
          "name": "6R-BH4 (sapropterin dihydrochloride)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "BioMarin Pharmaceutical",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 84,
      "start_date": "2006-05",
      "completion_date": "2008-12",
      "has_results": false,
      "last_update_posted_date": "2009-07-21",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 24,
      "location_summary": "Hoover, Alabama • Huntsville, Alabama • Mobile, Alabama + 21 more",
      "locations": [
        {
          "city": "Hoover",
          "state": "Alabama"
        },
        {
          "city": "Huntsville",
          "state": "Alabama"
        },
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "Muscle Shoals",
          "state": "Alabama"
        },
        {
          "city": "Gilbert",
          "state": "Arizona"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00325962"
    },
    {
      "nct_id": "NCT02353312",
      "title": "Rhode Island Diastolic Dysfunction - Heart Failure",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Heart Failure",
        "Cardiovascular Disease"
      ],
      "interventions": [
        {
          "name": "Kuvan",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Providence VA Medical Center",
      "sponsor_class": "FED",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 28,
      "start_date": "2015-03",
      "completion_date": "2018-12",
      "has_results": true,
      "last_update_posted_date": "2025-07-03",
      "last_synced_at": "2026-10-06T22:00:27.116Z",
      "location_count": 1,
      "location_summary": "Providence, Rhode Island",
      "locations": [
        {
          "city": "Providence",
          "state": "Rhode Island"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02353312"
    }
  ]
}