{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Antiestrogen+therapy",
    "query": {
      "intervention": "Antiestrogen therapy"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 75,
    "total_pages": 8,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Antiestrogen+therapy&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-12T12:10:51.956Z",
  "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": "NCT05304962",
      "title": "FIH Study of RGT-419B Alone and With Endocrine Therapy in HR-Positive, HER2-Negative Advanced/Metastatic Breast Cancer",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "RGT-419B",
          "type": "DRUG"
        },
        {
          "name": "RGT-419B in combination with hormonal therapy",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Regor Pharmaceuticals Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 64,
      "start_date": "2022-03-04",
      "completion_date": "2027-03-31",
      "has_results": false,
      "last_update_posted_date": "2026-08-12",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 8,
      "location_summary": "La Jolla, California • Los Angeles, California • Port Saint Lucie, Florida + 5 more",
      "locations": [
        {
          "city": "La Jolla",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Port Saint Lucie",
          "state": "Florida"
        },
        {
          "city": "Tampa",
          "state": "Florida"
        },
        {
          "city": "Atlanta",
          "state": "Georgia"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05304962"
    },
    {
      "nct_id": "NCT05826964",
      "title": "Levels of Circulating Tumor DNA as a Predictive Marker for Early Switch in Treatment for Patients With Metastatic (Stage IV) Breast Cancer",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer",
        "ER-positive Breast Cancer",
        "HER2-negative Breast Cancer",
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "AI+CDK4/6i",
          "type": "DRUG"
        },
        {
          "name": "SERD+CDK4/6i",
          "type": "DRUG"
        },
        {
          "name": "mTOR inhibitor + AI",
          "type": "DRUG"
        },
        {
          "name": "mTOR inhibitor + SERD",
          "type": "DRUG"
        },
        {
          "name": "mTOR inhibitor + Selective estrogen receptor modulator",
          "type": "DRUG"
        },
        {
          "name": "PI3K inhibitor + SERD",
          "type": "DRUG"
        },
        {
          "name": "PI3K inhibitor + AI",
          "type": "DRUG"
        },
        {
          "name": "Chemotherapy",
          "type": "DRUG"
        },
        {
          "name": "Oral SERD",
          "type": "DRUG"
        },
        {
          "name": "PARPi",
          "type": "DRUG"
        },
        {
          "name": "AKT inhibitor",
          "type": "DRUG"
        },
        {
          "name": "Step 3 Arm 2",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "University of Miami",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 24,
      "start_date": "2023-06-12",
      "completion_date": "2029-07-31",
      "has_results": false,
      "last_update_posted_date": "2026-01-13",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 1,
      "location_summary": "Miami, Florida",
      "locations": [
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05826964"
    },
    {
      "nct_id": "NCT06495164",
      "title": "A Real-life Study to Understand the Use and Effects of Palbociclib in US Patients With Breast Cancer",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Breast Cancer",
        "Malignant Neoplasm of Breast"
      ],
      "interventions": [
        {
          "name": "Palbociclib",
          "type": "DRUG"
        },
        {
          "name": "Aromatase inhibitor",
          "type": "DRUG"
        },
        {
          "name": "Ribociclib",
          "type": "DRUG"
        },
        {
          "name": "Abemaciclib",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Pfizer",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 1,
      "start_date": "2024-06-24",
      "completion_date": "2026-12-30",
      "has_results": false,
      "last_update_posted_date": "2025-11-25",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 1,
      "location_summary": "New York, New York",
      "locations": [
        {
          "city": "New York",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06495164"
    },
    {
      "nct_id": "NCT04964934",
      "title": "Phase III Study to Assess AZD9833+ CDK4/6 Inhibitor in HR+/HER2-MBC With Detectable ESR1m Before Progression (SERENA-6)",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "ER-Positive HER2-Negative Breast Cancer"
      ],
      "interventions": [
        {
          "name": "AZD9833",
          "type": "DRUG"
        },
        {
          "name": "AZD9833 Placebo",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole placebo",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Letrozole placebo",
          "type": "DRUG"
        },
        {
          "name": "Palbociclib",
          "type": "DRUG"
        },
        {
          "name": "Abemaciclib",
          "type": "DRUG"
        },
        {
          "name": "Luteinizing hormone-releasing hormone (LHRH) agonist",
          "type": "DRUG"
        },
        {
          "name": "Ribociclib",
          "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": 315,
      "start_date": "2021-06-30",
      "completion_date": "2028-09-01",
      "has_results": false,
      "last_update_posted_date": "2026-07-14",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 64,
      "location_summary": "Phoenix, Arizona • Hot Springs, Arkansas • Little Rock, Arkansas + 56 more",
      "locations": [
        {
          "city": "Phoenix",
          "state": "Arizona"
        },
        {
          "city": "Hot Springs",
          "state": "Arkansas"
        },
        {
          "city": "Little Rock",
          "state": "Arkansas"
        },
        {
          "city": "Long Beach",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04964934"
    },
    {
      "nct_id": "NCT04762979",
      "title": "Alpelisib (BYL719) in Combination With Continued Endocrine Therapy Following Progression on Endocrine Therapy in Hormone Receptor Positive, HER2 Negative, PIK3CA Mutant Metastatic Breast Cancer",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Hormone Receptor Positive Breast Carcinoma",
        "HER2-negative Breast Cancer",
        "PIK3CA Mutant Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Alpelisib",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "Aromatase inhibitor",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Marina N Sharifi",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 44,
      "start_date": "2021-02-12",
      "completion_date": "2026-05",
      "has_results": false,
      "last_update_posted_date": "2026-01-02",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 4,
      "location_summary": "Chicago, Illinois • Omaha, Nebraska • Hershey, Pennsylvania + 1 more",
      "locations": [
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Omaha",
          "state": "Nebraska"
        },
        {
          "city": "Hershey",
          "state": "Pennsylvania"
        },
        {
          "city": "Madison",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04762979"
    },
    {
      "nct_id": "NCT00830973",
      "title": "The Clinical and Economic Impact of Pharmacogenomic Testing for Tamoxifen Metabolism in Postmenopausal Women Receiving Tamoxifen for Prevention of Recurrent Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Breast Neoplasms",
        "Tamoxifen"
      ],
      "interventions": [
        {
          "name": "Poor Metabolism Status Follow Up Therapy Considerations",
          "type": "OTHER"
        },
        {
          "name": "CYP2D6 Inhibiting Drugs",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Medco Health Solutions, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "50 Years and older · Female only"
      },
      "enrollment_count": 184,
      "start_date": "2007-10",
      "completion_date": "2009-01",
      "has_results": false,
      "last_update_posted_date": "2009-10-14",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 1,
      "location_summary": "Franklin Lakes, New Jersey",
      "locations": [
        {
          "city": "Franklin Lakes",
          "state": "New Jersey"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00830973"
    },
    {
      "nct_id": "NCT00728949",
      "title": "A Study for Safety and Effectiveness of IMC-A12 by Itself or Combined With Antiestrogens to Treat Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "IMC-A12 (cixutumumab)",
          "type": "BIOLOGICAL"
        },
        {
          "name": "tamoxifen",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Exemestane",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "BIOLOGICAL",
        "DRUG"
      ],
      "sponsor": "Eli Lilly and Company",
      "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": 93,
      "start_date": "2008-08",
      "completion_date": "2015-02",
      "has_results": true,
      "last_update_posted_date": "2018-06-06",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 9,
      "location_summary": "Scottsdale, Arizona • Chicago, Illinois • Westwood, Kansas + 6 more",
      "locations": [
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Westwood",
          "state": "Kansas"
        },
        {
          "city": "Rochester",
          "state": "Minnesota"
        },
        {
          "city": "Lebanon",
          "state": "New Hampshire"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00728949"
    },
    {
      "nct_id": "NCT00365599",
      "title": "Phase II Trial of SAHA & Tamoxifen for Patients With Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "suberoylanilide hydroxamic acid (SAHA, Vorinostat)",
          "type": "DRUG"
        },
        {
          "name": "tamoxifen citrate (Tamoxifen)",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "H. Lee Moffitt Cancer Center and Research Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 43,
      "start_date": "2006-02",
      "completion_date": "2012-08",
      "has_results": true,
      "last_update_posted_date": "2014-11-21",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 8,
      "location_summary": "San Francisco, California • Boynton Beach, Florida • Orlando, Florida + 5 more",
      "locations": [
        {
          "city": "San Francisco",
          "state": "California"
        },
        {
          "city": "Boynton Beach",
          "state": "Florida"
        },
        {
          "city": "Orlando",
          "state": "Florida"
        },
        {
          "city": "Port Charlotte",
          "state": "Florida"
        },
        {
          "city": "Stuart",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00365599"
    },
    {
      "nct_id": "NCT00044291",
      "title": "Phase III Study of Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer",
      "overall_status": "COMPLETED",
      "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": "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": 865,
      "start_date": "2002-06",
      "completion_date": "2006-01",
      "has_results": false,
      "last_update_posted_date": "2015-07-31",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 17,
      "location_summary": "Lake Havasu City, Arizona • Tucson, Arizona • Greenbrae, California + 14 more",
      "locations": [
        {
          "city": "Lake Havasu City",
          "state": "Arizona"
        },
        {
          "city": "Tucson",
          "state": "Arizona"
        },
        {
          "city": "Greenbrae",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        },
        {
          "city": "Miami Shores",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00044291"
    },
    {
      "nct_id": "NCT00005970",
      "title": "Doxorubicin Hydrochloride, Cyclophosphamide, and Pacltaxel With or Without Trastuzumab in Treating Women With HER2-Positive Node-Positive or High-Risk Node-Negative Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Breast Adenocarcinoma",
        "HER2 Positive Breast Carcinoma",
        "Stage IA Breast Cancer AJCC v7",
        "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"
      ],
      "interventions": [
        {
          "name": "Aromatase Inhibition Therapy",
          "type": "DRUG"
        },
        {
          "name": "Cyclophosphamide",
          "type": "DRUG"
        },
        {
          "name": "Doxorubicin Hydrochloride",
          "type": "DRUG"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Paclitaxel",
          "type": "DRUG"
        },
        {
          "name": "Tamoxifen Citrate",
          "type": "DRUG"
        },
        {
          "name": "Trastuzumab",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER",
        "BIOLOGICAL"
      ],
      "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": 3436,
      "start_date": "2000-05-19",
      "completion_date": "2010-01-27",
      "has_results": false,
      "last_update_posted_date": "2020-08-14",
      "last_synced_at": "2026-09-12T12:10:51.956Z",
      "location_count": 154,
      "location_summary": "Birmingham, Alabama • Phoenix, Arizona • Scottsdale, Arizona + 119 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Phoenix",
          "state": "Arizona"
        },
        {
          "city": "Scottsdale",
          "state": "Arizona"
        },
        {
          "city": "Tucson",
          "state": "Arizona"
        },
        {
          "city": "Little Rock",
          "state": "Arkansas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00005970"
    }
  ]
}