{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Challenge&page=20",
    "query": {
      "intervention": "Challenge",
      "page": 20
    },
    "page_size": 10
  },
  "pagination": {
    "page": 20,
    "page_size": 10,
    "total_count": 1539,
    "total_pages": 154,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Challenge&page=21&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Challenge&page=19&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-24T16:18:49.293Z",
  "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": "NCT01435811",
      "title": "Dose Range Evaluation of Norovirus Challenge Pool (GII.4, CIN-1)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Norovirus Infections"
      ],
      "interventions": [
        {
          "name": "Norovirus challenge pool (GII.4, CIN-1)",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Children's Hospital Medical Center, Cincinnati",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "49 Years",
        "sex": "ALL",
        "summary": "18 Years to 49 Years"
      },
      "enrollment_count": 60,
      "start_date": "2011-08",
      "completion_date": "2012-11",
      "has_results": false,
      "last_update_posted_date": "2014-05-07",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Cincinnati, Ohio",
      "locations": [
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01435811"
    },
    {
      "nct_id": "NCT00791102",
      "title": "Topical ASP-1001 (Contrast Media Formulation) and the Acute Response to Nasal Allergen Challenge (NAC)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2",
        "PHASE3"
      ],
      "conditions": [
        "Allergic Rhinitis"
      ],
      "interventions": [
        {
          "name": "ASP-1001 nasal spray",
          "type": "DRUG"
        },
        {
          "name": "Placebo for ASP-1001",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Chicago",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Days",
        "maximum_age": "55 Years",
        "sex": "ALL",
        "summary": "18 Days to 55 Years"
      },
      "enrollment_count": 20,
      "start_date": "2010-01",
      "completion_date": "2010-12",
      "has_results": true,
      "last_update_posted_date": "2013-07-10",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Chicago, Illinois",
      "locations": [
        {
          "city": "Chicago",
          "state": "Illinois"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00791102"
    },
    {
      "nct_id": "NCT00887302",
      "title": "Metabolomics of Roux-en-Y Gastric Bypass (RYGB) With Gastrostomy",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Type II Diabetes Mellitus",
        "Obesity"
      ],
      "interventions": [
        {
          "name": "Gastric Band",
          "type": "PROCEDURE"
        },
        {
          "name": "Gastric Sleeve",
          "type": "PROCEDURE"
        },
        {
          "name": "Gastrostomy Tube",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "PROCEDURE"
      ],
      "sponsor": "East Carolina University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "60 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 60 Years · Female only"
      },
      "enrollment_count": 13,
      "start_date": "2009-03-25",
      "completion_date": "2012-10-12",
      "has_results": false,
      "last_update_posted_date": "2023-10-06",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Greenville, North Carolina",
      "locations": [
        {
          "city": "Greenville",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00887302"
    },
    {
      "nct_id": "NCT02153944",
      "title": "Cognitive vs. Emotional Psychopharmacological Manipulations of Fear vs. Anxiety",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Anxiety Disorder"
      ],
      "interventions": [
        {
          "name": "Propranolol",
          "type": "DRUG"
        },
        {
          "name": "Methylphenidate",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "National Institute of Mental Health (NIMH)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 142,
      "start_date": "2014-06-16",
      "completion_date": "2021-10-07",
      "has_results": true,
      "last_update_posted_date": "2023-04-11",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Bethesda, Maryland",
      "locations": [
        {
          "city": "Bethesda",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02153944"
    },
    {
      "nct_id": "NCT02500628",
      "title": "Heart Rate Variability in Response to Metformin Challenge",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Fibromyalgia",
        "Mitochondrial Diseases",
        "Movement Disorders",
        "Diabetes Mellitus, Type 2"
      ],
      "interventions": [
        {
          "name": "Metformin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Woodinville Psychiatric Associates",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 61,
      "start_date": "2015-07",
      "completion_date": "2016-02",
      "has_results": true,
      "last_update_posted_date": "2018-01-03",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Woodinville, Washington",
      "locations": [
        {
          "city": "Woodinville",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02500628"
    },
    {
      "nct_id": "NCT07279467",
      "title": "Study of Oral Food Challenge Biomarkers (SAFER)",
      "overall_status": "RECRUITING",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Allergy"
      ],
      "interventions": [
        {
          "name": "Oral Food Challenge (OFC): Peanut Protein",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "National Institute of Allergy and Infectious Diseases (NIAID)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "12 Months",
        "maximum_age": "17 Years",
        "sex": "ALL",
        "summary": "12 Months to 17 Years"
      },
      "enrollment_count": 500,
      "start_date": "2026-08-20",
      "completion_date": "2027-12-01",
      "has_results": false,
      "last_update_posted_date": "2026-10-23",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 10,
      "location_summary": "Little Rock, Arkansas • Palo Alto, California • Chicago, Illinois + 7 more",
      "locations": [
        {
          "city": "Little Rock",
          "state": "Arkansas"
        },
        {
          "city": "Palo Alto",
          "state": "California"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Baltimore",
          "state": "Maryland"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07279467"
    },
    {
      "nct_id": "NCT00086606",
      "title": "A Safety and Efficacy Study of Xolair in Peanut Allergy",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Allergy"
      ],
      "interventions": [
        {
          "name": "Xolair (omalizumab)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Genentech, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "6 Years",
        "maximum_age": "75 Years",
        "sex": "ALL",
        "summary": "6 Years to 75 Years"
      },
      "enrollment_count": 150,
      "start_date": "2004-06",
      "completion_date": "2006-04",
      "has_results": false,
      "last_update_posted_date": "2013-01-21",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Denver, Colorado",
      "locations": [
        {
          "city": "Denver",
          "state": "Colorado"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00086606"
    },
    {
      "nct_id": "NCT01696344",
      "title": "Does Atrial Fibrillation (AF) Termination Without Additional Ablation Influence Outcome?",
      "overall_status": "UNKNOWN",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Atrial Fibrillation"
      ],
      "interventions": [
        {
          "name": "PVAI",
          "type": "PROCEDURE"
        },
        {
          "name": "PVAI + ablation of extraPV triggers",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "PROCEDURE"
      ],
      "sponsor": "Texas Cardiac Arrhythmia Research Foundation",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "80 Years",
        "sex": "ALL",
        "summary": "18 Years to 80 Years"
      },
      "enrollment_count": 60,
      "start_date": "2012-05",
      "completion_date": "2019-12",
      "has_results": false,
      "last_update_posted_date": "2019-04-10",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 2,
      "location_summary": "Austin, Texas",
      "locations": [
        {
          "city": "Austin",
          "state": "Texas"
        },
        {
          "city": "Austin",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01696344"
    },
    {
      "nct_id": "NCT05031455",
      "title": "Mechanisms of Dupilumab in AERD",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Aspirin-exacerbated Respiratory Disease"
      ],
      "interventions": [
        {
          "name": "Aspirin Challenge",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Scripps Clinic",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 16,
      "start_date": "2024-03-25",
      "completion_date": "2026-04-20",
      "has_results": false,
      "last_update_posted_date": "2026-04-28",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "San Diego, California",
      "locations": [
        {
          "city": "San Diego",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05031455"
    },
    {
      "nct_id": "NCT00313404",
      "title": "Infectivity of Norovirus in Groundwater-Human Challenge Study",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Healthy"
      ],
      "interventions": [
        {
          "name": "Safety tested norovirus inoculum",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL"
      ],
      "sponsor": "Emory University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 13,
      "start_date": "2006-02",
      "completion_date": "2011-04",
      "has_results": false,
      "last_update_posted_date": "2013-11-19",
      "last_synced_at": "2026-10-24T16:18:49.293Z",
      "location_count": 1,
      "location_summary": "Atlanta, Georgia",
      "locations": [
        {
          "city": "Atlanta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00313404"
    }
  ]
}