{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?condition=Estrogen-receptor+Positive+Breast+Cancer",
    "query": {
      "condition": "Estrogen-receptor Positive Breast Cancer"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 391,
    "total_pages": 40,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?condition=Estrogen-receptor+Positive+Breast+Cancer&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-07-23T16:43:33.448Z",
  "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": "NCT00661531",
      "title": "Estrogen in Postmenopausal Women With ER Positive Metastatic Breast Cancer After Failure of Sequential Endocrine Therapy",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer",
        "Cancer of the Breast",
        "Neoplasms, Breast"
      ],
      "interventions": [
        {
          "name": "Estrace",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Georgetown University",
      "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": 11,
      "start_date": "2008-04",
      "completion_date": "2015-06",
      "has_results": true,
      "last_update_posted_date": "2017-04-12",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 3,
      "location_summary": "Washington D.C., District of Columbia • Voorhees Township, New Jersey • Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Washington D.C.",
          "state": "District of Columbia"
        },
        {
          "city": "Voorhees Township",
          "state": "New Jersey"
        },
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00661531"
    },
    {
      "nct_id": "NCT04975308",
      "title": "A Study of Imlunestrant, Investigator's Choice of Endocrine Therapy, and Imlunestrant Plus Abemaciclib in Participants With ER+, HER2- Advanced Breast Cancer",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Breast Neoplasms",
        "Neoplasm Metastasis"
      ],
      "interventions": [
        {
          "name": "Imlunestrant",
          "type": "DRUG"
        },
        {
          "name": "Exemestane",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "Abemaciclib",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Eli Lilly and Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 874,
      "start_date": "2021-10-04",
      "completion_date": "2027-08",
      "has_results": true,
      "last_update_posted_date": "2026-07-22",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 48,
      "location_summary": "Chandler, Arizona • Gilbert, Arizona • Greenbrae, California + 29 more",
      "locations": [
        {
          "city": "Chandler",
          "state": "Arizona"
        },
        {
          "city": "Gilbert",
          "state": "Arizona"
        },
        {
          "city": "Greenbrae",
          "state": "California"
        },
        {
          "city": "Sacramento",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04975308"
    },
    {
      "nct_id": "NCT03321981",
      "title": "MCLA-128 With Trastuzumab/Chemotherapy in HER2+ and With Endocrine Therapy in ER+ and Low HER2 Breast Cancer.",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer Metastatic"
      ],
      "interventions": [
        {
          "name": "Zenocutuzumab",
          "type": "DRUG"
        },
        {
          "name": "Trastuzumab",
          "type": "DRUG"
        },
        {
          "name": "Vinorelbine",
          "type": "DRUG"
        },
        {
          "name": "Endocrine therapy",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Merus B.V.",
      "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": 105,
      "start_date": "2018-01-15",
      "completion_date": "2023-07-26",
      "has_results": true,
      "last_update_posted_date": "2024-03-07",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 3,
      "location_summary": "Los Angeles, California • Kansas City, Kansas • Nashville, Tennessee",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Kansas City",
          "state": "Kansas"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03321981"
    },
    {
      "nct_id": "NCT05837455",
      "title": "NeoTAILOR: ABiomarker-directed Approach to Guide Neoadjuvant Therapy for Patients With Stage II/III ER-positive, HER2-negative Breast Cancer",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer",
        "Cancer of the Breast"
      ],
      "interventions": [
        {
          "name": "VENTANA MIB-1 Ki67 assay",
          "type": "DEVICE"
        },
        {
          "name": "Oncotype DX® Recurrence Score",
          "type": "DEVICE"
        },
        {
          "name": "PAM50-based Prosigna breast cancer gene signature assay",
          "type": "DEVICE"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Combination anthracycline and/or taxane based treatment",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DEVICE",
        "DRUG"
      ],
      "sponsor": "Washington University School of Medicine",
      "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": 81,
      "start_date": "2024-05-30",
      "completion_date": "2027-11-30",
      "has_results": false,
      "last_update_posted_date": "2026-04-13",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05837455"
    },
    {
      "nct_id": "NCT01027416",
      "title": "Analyzing a New Mechanism in Response to Tamoxifen Therapy in Breast Cancer Patients",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Tamoxifen",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Roswell Park Cancer Institute",
      "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": 59,
      "start_date": "2009-12-14",
      "completion_date": "2015-12",
      "has_results": true,
      "last_update_posted_date": "2026-04-21",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 2,
      "location_summary": "Chicago, Illinois • Buffalo, New York",
      "locations": [
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01027416"
    },
    {
      "nct_id": "NCT06428396",
      "title": "Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Belzutifan",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "Everolimus",
          "type": "DRUG"
        },
        {
          "name": "Exemestane",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Merck Sharp & Dohme LLC",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 120,
      "start_date": "2024-11-27",
      "completion_date": "2028-12-25",
      "has_results": false,
      "last_update_posted_date": "2026-07-10",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 14,
      "location_summary": "Goodyear, Arizona • Beverly Hills, California • La Jolla, California + 11 more",
      "locations": [
        {
          "city": "Goodyear",
          "state": "Arizona"
        },
        {
          "city": "Beverly Hills",
          "state": "California"
        },
        {
          "city": "La Jolla",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Newport Beach",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06428396"
    },
    {
      "nct_id": "NCT03359954",
      "title": "Radiation Therapy Before Surgery in Treating Patients With Hormone Receptor Positive, HER2 Negative Breast Cancer",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Estrogen Receptor Positive",
        "HER2/Neu Negative",
        "Invasive Breast Carcinoma",
        "Progesterone Receptor Positive"
      ],
      "interventions": [
        {
          "name": "Radiation Therapy",
          "type": "RADIATION"
        },
        {
          "name": "Therapeutic Conventional Surgery",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "RADIATION",
        "PROCEDURE"
      ],
      "sponsor": "M.D. Anderson Cancer Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 25,
      "start_date": "2017-11-16",
      "completion_date": "2027-10-31",
      "has_results": false,
      "last_update_posted_date": "2026-03-05",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 1,
      "location_summary": "Houston, Texas",
      "locations": [
        {
          "city": "Houston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03359954"
    },
    {
      "nct_id": "NCT05549505",
      "title": "A Trial Using ARV-471 or Anastrozole in Post-Menopausal Women With Breast Cancer Prior to Surgery",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "ARV-471",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Surgical resection of breast tumor",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "DRUG",
        "PROCEDURE"
      ],
      "sponsor": "Arvinas Inc.",
      "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": 152,
      "start_date": "2023-02-15",
      "completion_date": "2024-07-25",
      "has_results": true,
      "last_update_posted_date": "2025-08-29",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 13,
      "location_summary": "Springdale, Arkansas • Los Angeles, California • Torrance, California + 10 more",
      "locations": [
        {
          "city": "Springdale",
          "state": "Arkansas"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Torrance",
          "state": "California"
        },
        {
          "city": "Van Nuys",
          "state": "California"
        },
        {
          "city": "Fort Lauderdale",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05549505"
    },
    {
      "nct_id": "NCT05080842",
      "title": "A Study of AC682 for the Treatment of Locally Advanced or Metastatic ER+ Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "AC682",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Accutar Biotechnology Inc",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 21,
      "start_date": "2021-11-12",
      "completion_date": "2024-04-04",
      "has_results": false,
      "last_update_posted_date": "2025-02-13",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 5,
      "location_summary": "Denver, Colorado • Orlando, Florida • Sarasota, Florida + 2 more",
      "locations": [
        {
          "city": "Denver",
          "state": "Colorado"
        },
        {
          "city": "Orlando",
          "state": "Florida"
        },
        {
          "city": "Sarasota",
          "state": "Florida"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        },
        {
          "city": "Houston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05080842"
    },
    {
      "nct_id": "NCT01808040",
      "title": "A Phase 1b Study of TAK-700 in Postmenopausal Women With Hormone-receptor Positive Metastatic Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Post Menopausal, Hormone Receptor Positive Breast Cancer"
      ],
      "interventions": [
        {
          "name": "TAK700",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Wisconsin, Madison",
      "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": 8,
      "start_date": "2012-11",
      "completion_date": "2016-12-09",
      "has_results": false,
      "last_update_posted_date": "2019-11-18",
      "last_synced_at": "2026-07-23T16:43:33.448Z",
      "location_count": 1,
      "location_summary": "Madison, Wisconsin",
      "locations": [
        {
          "city": "Madison",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01808040"
    }
  ]
}