{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Estrogen+Receptor+Antagonist&page=2",
    "query": {
      "intervention": "Estrogen Receptor Antagonist",
      "page": 2
    },
    "page_size": 10
  },
  "pagination": {
    "page": 2,
    "page_size": 10,
    "total_count": 93,
    "total_pages": 10,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Estrogen+Receptor+Antagonist&page=3&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Estrogen+Receptor+Antagonist&page=1&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-02T15:25:50.581Z",
  "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": "NCT01694225",
      "title": "Adherence Rate of Monthly Bubble Package Among Patients Prescribed Adjuvant Endocrine Therapy in Breast Cancer Survivors",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "bubble packaging for monthly prescription",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "University of Louisville",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 87,
      "start_date": "2012-07",
      "completion_date": "2018-01-28",
      "has_results": false,
      "last_update_posted_date": "2018-01-31",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 1,
      "location_summary": "Louisville, Kentucky",
      "locations": [
        {
          "city": "Louisville",
          "state": "Kentucky"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01694225"
    },
    {
      "nct_id": "NCT06218303",
      "title": "Prototype DAA/TAA Vaccine Targeting MUC1 for Immune Interception and Prevention in Ductal Carcinoma In Situ",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Ductal Carcinoma in Situ"
      ],
      "interventions": [
        {
          "name": "MUC1 Peptide Vaccine",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Hiltonol®",
          "type": "DRUG"
        },
        {
          "name": "Aromatase Inhibitor",
          "type": "DRUG"
        },
        {
          "name": "Selective estrogen receptor modulator (SERM)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "DRUG"
      ],
      "sponsor": "Finn, Olivera, PhD",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 50,
      "start_date": "2024-02-07",
      "completion_date": "2029-12-31",
      "has_results": false,
      "last_update_posted_date": "2026-08-18",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 1,
      "location_summary": "Pittsburgh, Pennsylvania",
      "locations": [
        {
          "city": "Pittsburgh",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06218303"
    },
    {
      "nct_id": "NCT02911844",
      "title": "Estrogen Receptor Antagonist in Patients With Pulmonary Arterial Hypertension",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Pulmonary Arterial Hypertension"
      ],
      "interventions": [
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Pennsylvania",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 5,
      "start_date": "2017-04-10",
      "completion_date": "2018-12-05",
      "has_results": true,
      "last_update_posted_date": "2019-12-09",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 1,
      "location_summary": "Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02911844"
    },
    {
      "nct_id": "NCT04711252",
      "title": "A Comparative Study of AZD9833 Plus Palbociclib Versus Anastrozole Plus Palbociclib in Patients With ER-Positive HER2 Negative Breast Cancer Who Have Not Received Any Systemic Treatment for Advanced Disease",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "ER-Positive HER2-Negative Breast Cancer"
      ],
      "interventions": [
        {
          "name": "AZD9833",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole placebo",
          "type": "DRUG"
        },
        {
          "name": "AZD9833 placebo",
          "type": "DRUG"
        },
        {
          "name": "Palbociclib",
          "type": "DRUG"
        },
        {
          "name": "Luteinizing hormone-releasing hormone (LHRH) agonist",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "AstraZeneca",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "130 Years",
        "sex": "ALL",
        "summary": "18 Years to 130 Years"
      },
      "enrollment_count": 1371,
      "start_date": "2021-01-28",
      "completion_date": "2029-02-01",
      "has_results": false,
      "last_update_posted_date": "2026-09-28",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 30,
      "location_summary": "Mobile, Alabama • Springdale, Arkansas • Harbor City, California + 25 more",
      "locations": [
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "Springdale",
          "state": "Arkansas"
        },
        {
          "city": "Harbor City",
          "state": "California"
        },
        {
          "city": "Solvang",
          "state": "California"
        },
        {
          "city": "Lone Tree",
          "state": "Colorado"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04711252"
    },
    {
      "nct_id": "NCT01971515",
      "title": "First-in-Human Dose Escalation Trial in Subjects With Advanced Malignancies",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Solid Tumor"
      ],
      "interventions": [
        {
          "name": "MSC2363318A",
          "type": "DRUG"
        },
        {
          "name": "MSC2363318A plus Trastuzumab",
          "type": "DRUG"
        },
        {
          "name": "MSC2363318A plus Tamoxifen",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "EMD Serono",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 101,
      "start_date": "2013-12-13",
      "completion_date": "2018-08-09",
      "has_results": false,
      "last_update_posted_date": "2018-09-19",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 15,
      "location_summary": "Birmingham, Alabama • Los Angeles, California • San Diego, California + 11 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Miami",
          "state": "Florida"
        },
        {
          "city": "Metairie",
          "state": "Louisiana"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01971515"
    },
    {
      "nct_id": "NCT04247126",
      "title": "A Study of SY 5609, a Selective CDK7 Inhibitor, in Advanced Solid Tumors",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Advanced Solid Tumor",
        "Breast Cancer",
        "Small-cell Lung Cancer",
        "Pancreatic Cancer"
      ],
      "interventions": [
        {
          "name": "SY-5609",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "Gemcitabine",
          "type": "DRUG"
        },
        {
          "name": "Nab-paclitaxel",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Syros Pharmaceuticals",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 105,
      "start_date": "2020-01-23",
      "completion_date": "2023-03-30",
      "has_results": false,
      "last_update_posted_date": "2023-10-27",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 16,
      "location_summary": "Gilbert, Arizona • Los Angeles, California • Orlando, Florida + 11 more",
      "locations": [
        {
          "city": "Gilbert",
          "state": "Arizona"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Orlando",
          "state": "Florida"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04247126"
    },
    {
      "nct_id": "NCT00097344",
      "title": "The CAT Study: Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Breast Neoplasms",
        "Neoplasms, Hormone-Dependent"
      ],
      "interventions": [
        {
          "name": "Atamestane",
          "type": "DRUG"
        },
        {
          "name": "Toremifene",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Aromatase inhibition",
          "type": "DRUG"
        },
        {
          "name": "Estrogen receptor blocker",
          "type": "DRUG"
        },
        {
          "name": "Hormone therapy",
          "type": "PROCEDURE"
        },
        {
          "name": "Endocrine therapy",
          "type": "PROCEDURE"
        },
        {
          "name": "Antiestrogen therapy",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "DRUG",
        "PROCEDURE"
      ],
      "sponsor": "Intarcia Therapeutics",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 842,
      "start_date": "2004-12",
      "completion_date": "2006-08",
      "has_results": false,
      "last_update_posted_date": "2007-08-23",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 49,
      "location_summary": "Mobile, Alabama • Tuscon, Arizona • Hot Springs, Arkansas + 46 more",
      "locations": [
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "Tuscon",
          "state": "Arizona"
        },
        {
          "city": "Hot Springs",
          "state": "Arkansas"
        },
        {
          "city": "Fountain Valley",
          "state": "California"
        },
        {
          "city": "Greenbrae",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00097344"
    },
    {
      "nct_id": "NCT00386022",
      "title": "The Effects of Aging and Estrogen on the Pituitary",
      "overall_status": "UNKNOWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2",
        "PHASE3"
      ],
      "conditions": [
        "Healthy"
      ],
      "interventions": [
        {
          "name": "GnRH",
          "type": "DRUG"
        },
        {
          "name": "NAL-GLU GnRH antagonist",
          "type": "DRUG"
        },
        {
          "name": "Estrogen patch",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Massachusetts General Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "45 Years",
        "maximum_age": "80 Years",
        "sex": "FEMALE",
        "summary": "45 Years to 80 Years · Female only"
      },
      "enrollment_count": 19,
      "start_date": "2002-01",
      "completion_date": "2018-01",
      "has_results": true,
      "last_update_posted_date": "2017-04-13",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00386022"
    },
    {
      "nct_id": "NCT01219699",
      "title": "A Study of BYL719 in Adult Patients With Advanced Solid Malignancies, Whose Tumors Have an Alteration of the PIK3CA Gene",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Advanced Solid Tumors With an Alteration of the PIK3CA Gene",
        "Estrogen Receptor Positive Breast Cancer"
      ],
      "interventions": [
        {
          "name": "BYL719",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Novartis Pharmaceuticals",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 221,
      "start_date": "2010-10-05",
      "completion_date": "2020-04-16",
      "has_results": false,
      "last_update_posted_date": "2020-09-22",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 5,
      "location_summary": "San Francisco, California • Boston, Massachusetts • Nashville, Tennessee + 1 more",
      "locations": [
        {
          "city": "San Francisco",
          "state": "California"
        },
        {
          "city": "Boston",
          "state": "Massachusetts"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        },
        {
          "city": "Houston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01219699"
    },
    {
      "nct_id": "NCT02003209",
      "title": "Docetaxel, Carboplatin, Trastuzumab, and Pertuzumab With or Without Estrogen Deprivation in Treating Patients With Hormone Receptor-Positive, HER2-Positive Operable or Locally Advanced Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "HER2-Positive Breast Carcinoma",
        "Hormone Receptor-Positive Breast Carcinoma",
        "Stage IB Breast Cancer AJCC v7",
        "Stage IIA Breast Cancer AJCC v6 and v7",
        "Stage IIB Breast Cancer AJCC v6 and v7",
        "Stage IIIA Breast Cancer AJCC v7",
        "Stage IIIB Breast Cancer AJCC v7",
        "Stage IIIC Breast Cancer AJCC v7"
      ],
      "interventions": [
        {
          "name": "Aromatase Inhibition Therapy",
          "type": "DRUG"
        },
        {
          "name": "Carboplatin",
          "type": "DRUG"
        },
        {
          "name": "Cytology Specimen Collection Procedure",
          "type": "OTHER"
        },
        {
          "name": "Docetaxel",
          "type": "DRUG"
        },
        {
          "name": "Goserelin Acetate",
          "type": "DRUG"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Pertuzumab",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Quality-of-Life Assessment",
          "type": "OTHER"
        },
        {
          "name": "Therapeutic Conventional Surgery",
          "type": "PROCEDURE"
        },
        {
          "name": "Trastuzumab",
          "type": "BIOLOGICAL"
        },
        {
          "name": "Whole Breast Irradiation",
          "type": "RADIATION"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER",
        "BIOLOGICAL",
        "PROCEDURE",
        "RADIATION"
      ],
      "sponsor": "National Cancer Institute (NCI)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 315,
      "start_date": "2014-02-18",
      "completion_date": "2025-06-30",
      "has_results": true,
      "last_update_posted_date": "2025-08-08",
      "last_synced_at": "2026-10-02T15:25:50.581Z",
      "location_count": 731,
      "location_summary": "Fairbanks, Alaska • Hot Springs, Arkansas • Anaheim, California + 465 more",
      "locations": [
        {
          "city": "Fairbanks",
          "state": "Alaska"
        },
        {
          "city": "Hot Springs",
          "state": "Arkansas"
        },
        {
          "city": "Anaheim",
          "state": "California"
        },
        {
          "city": "Antioch",
          "state": "California"
        },
        {
          "city": "Arroyo Grande",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02003209"
    }
  ]
}