{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?condition=ER-negative+Breast+Cancer&page=5",
    "query": {
      "condition": "ER-negative Breast Cancer",
      "page": 5
    },
    "page_size": 10
  },
  "pagination": {
    "page": 5,
    "page_size": 10,
    "total_count": 495,
    "total_pages": 50,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?condition=ER-negative+Breast+Cancer&page=6&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?condition=ER-negative+Breast+Cancer&page=4&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-04T06:34:50.803Z",
  "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": "NCT04872166",
      "title": "A Study of BTX-A51 in People With Advanced Solid Tumor and Breast Cancer",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Advanced Solid Tumor",
        "Metastatic Breast Cancer"
      ],
      "interventions": [
        {
          "name": "BTX-A51",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Edgewood Oncology Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 112,
      "start_date": "2021-06-07",
      "completion_date": "2027-05",
      "has_results": false,
      "last_update_posted_date": "2025-01-30",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 6,
      "location_summary": "Lake Mary, Florida • Sarasota, Florida • Cincinnati, Ohio + 2 more",
      "locations": [
        {
          "city": "Lake Mary",
          "state": "Florida"
        },
        {
          "city": "Sarasota",
          "state": "Florida"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04872166"
    },
    {
      "nct_id": "NCT00516542",
      "title": "Dehydroepiandrosterone (DHEA) and Letrozole in Treating Patients With Metastatic Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "letrozole",
          "type": "DRUG"
        },
        {
          "name": "DHEA",
          "type": "DRUG"
        },
        {
          "name": "pharmacological study",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "OHSU Knight Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "60 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "60 Years and older"
      },
      "enrollment_count": 6,
      "start_date": "2007-06",
      "completion_date": "2010-12",
      "has_results": false,
      "last_update_posted_date": "2012-07-24",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 1,
      "location_summary": "Portland, Oregon",
      "locations": [
        {
          "city": "Portland",
          "state": "Oregon"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00516542"
    },
    {
      "nct_id": "NCT02384746",
      "title": "Phase I Study of the Combination of MLN9708 and Fulvestrant",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "MLN9708",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Dartmouth-Hitchcock Medical Center",
      "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": 9,
      "start_date": "2015-06-02",
      "completion_date": "2018-06-10",
      "has_results": false,
      "last_update_posted_date": "2019-04-29",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 1,
      "location_summary": "Lebanon, New Hampshire",
      "locations": [
        {
          "city": "Lebanon",
          "state": "New Hampshire"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02384746"
    },
    {
      "nct_id": "NCT01740427",
      "title": "A Study of Palbociclib (PD-0332991) + Letrozole vs. Letrozole For 1st Line Treatment Of Postmenopausal Women With ER+/HER2- Advanced Breast Cancer (PALOMA-2)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Breast Neoplasms"
      ],
      "interventions": [
        {
          "name": "PD-0332991",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Pfizer",
      "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": 666,
      "start_date": "2013-02-22",
      "completion_date": "2023-11-09",
      "has_results": true,
      "last_update_posted_date": "2024-11-14",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 136,
      "location_summary": "Bellflower, California • Beverly Hills, California • Fullerton, California + 83 more",
      "locations": [
        {
          "city": "Bellflower",
          "state": "California"
        },
        {
          "city": "Beverly Hills",
          "state": "California"
        },
        {
          "city": "Fullerton",
          "state": "California"
        },
        {
          "city": "Glendale",
          "state": "California"
        },
        {
          "city": "Irvine",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01740427"
    },
    {
      "nct_id": "NCT00194792",
      "title": "Hormone Therapy and Combination Chemotherapy Before and After Surgery in Treating Patients With Stage I-IIIA Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Estrogen Receptor-positive Breast Cancer",
        "HER2-negative Breast Cancer",
        "Progesterone Receptor-positive Breast Cancer",
        "Stage I Breast Cancer",
        "Stage II Breast Cancer",
        "Stage IIIA Breast Cancer"
      ],
      "interventions": [
        {
          "name": "exemestane",
          "type": "DRUG"
        },
        {
          "name": "triptorelin pamoate",
          "type": "DRUG"
        },
        {
          "name": "capecitabine",
          "type": "DRUG"
        },
        {
          "name": "methotrexate",
          "type": "DRUG"
        },
        {
          "name": "vinorelbine tartrate",
          "type": "DRUG"
        },
        {
          "name": "paclitaxel",
          "type": "DRUG"
        },
        {
          "name": "therapeutic conventional surgery",
          "type": "PROCEDURE"
        },
        {
          "name": "radiation therapy",
          "type": "RADIATION"
        },
        {
          "name": "laboratory biomarker analysis",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "PROCEDURE",
        "RADIATION",
        "OTHER"
      ],
      "sponsor": "University of Washington",
      "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": 28,
      "start_date": "2005-08",
      "completion_date": "2011-07",
      "has_results": true,
      "last_update_posted_date": "2017-07-11",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 1,
      "location_summary": "Seattle, Washington",
      "locations": [
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00194792"
    },
    {
      "nct_id": "NCT05618613",
      "title": "Study of Elacestrant in Combination With Onapristone in Patients With Advanced or Metastatic Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Elacestrant",
          "type": "DRUG"
        },
        {
          "name": "Onapristone",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Context Therapeutics Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 4,
      "start_date": "2022-12-02",
      "completion_date": "2023-06-23",
      "has_results": true,
      "last_update_posted_date": "2026-07-21",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 3,
      "location_summary": "Phoenix, Arizona • Zion, Illinois • Nashville, Tennessee",
      "locations": [
        {
          "city": "Phoenix",
          "state": "Arizona"
        },
        {
          "city": "Zion",
          "state": "Illinois"
        },
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05618613"
    },
    {
      "nct_id": "NCT06126003",
      "title": "Gut and Tumor Microbiome in Patients With Early Stage (II-III), Locally Advanced or Advanced ER-positive and HER2-negative Breast Cancer.",
      "overall_status": "TERMINATED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Observation",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "BioCorteX Inc",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "85 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 85 Years · Female only"
      },
      "enrollment_count": 2,
      "start_date": "2023-12-01",
      "completion_date": "2024-07-31",
      "has_results": false,
      "last_update_posted_date": "2024-08-02",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 6,
      "location_summary": "Decatur, Illinois • Las Vegas, Nevada • Belleville, New Jersey + 3 more",
      "locations": [
        {
          "city": "Decatur",
          "state": "Illinois"
        },
        {
          "city": "Las Vegas",
          "state": "Nevada"
        },
        {
          "city": "Belleville",
          "state": "New Jersey"
        },
        {
          "city": "Ithaca",
          "state": "New York"
        },
        {
          "city": "Toledo",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06126003"
    },
    {
      "nct_id": "NCT04072952",
      "title": "A Phase 1/2 Trial of ARV-471 Alone and in Combination With Palbociclib (IBRANCE®) in Participants With ER+/HER2- Locally Advanced or Metastatic Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Vepdegestrant",
          "type": "DRUG"
        },
        {
          "name": "Palbociclib",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Arvinas Estrogen Receptor, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 219,
      "start_date": "2019-09-22",
      "completion_date": "2026-03-05",
      "has_results": true,
      "last_update_posted_date": "2026-09-29",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 16,
      "location_summary": "Palo Alto, California • San Francisco, California • Santa Monica, California + 12 more",
      "locations": [
        {
          "city": "Palo Alto",
          "state": "California"
        },
        {
          "city": "San Francisco",
          "state": "California"
        },
        {
          "city": "Santa Monica",
          "state": "California"
        },
        {
          "city": "Norwalk",
          "state": "Connecticut"
        },
        {
          "city": "Fort Myers",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04072952"
    },
    {
      "nct_id": "NCT04059484",
      "title": "Phase 2 Study of Amcenestrant (SAR439859) Versus Physician's Choice in Locally Advanced or Metastatic ER-positive Breast Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer Metastatic"
      ],
      "interventions": [
        {
          "name": "Amcenestrant",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Exemestane",
          "type": "DRUG"
        },
        {
          "name": "Tamoxifen",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Sanofi",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 367,
      "start_date": "2019-10-22",
      "completion_date": "2025-01-02",
      "has_results": true,
      "last_update_posted_date": "2026-02-24",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 14,
      "location_summary": "Birmingham, Alabama • Bakersfield, California • Santa Monica, California + 11 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Bakersfield",
          "state": "California"
        },
        {
          "city": "Santa Monica",
          "state": "California"
        },
        {
          "city": "Fairway",
          "state": "Kansas"
        },
        {
          "city": "Baton Rouge",
          "state": "Louisiana"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04059484"
    },
    {
      "nct_id": "NCT00938652",
      "title": "A Phase 3, Multi-Center Study of Gemcitabine/Carboplatin, With or Without BSI-201, in Patients With ER-, PR-, and Her2-Negative Metastatic Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "gemcitabine/carboplatin",
          "type": "DRUG"
        },
        {
          "name": "Iniparib",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Sanofi",
      "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": 519,
      "start_date": "2009-07",
      "completion_date": "2012-02",
      "has_results": false,
      "last_update_posted_date": "2013-09-19",
      "last_synced_at": "2026-10-04T06:34:50.803Z",
      "location_count": 102,
      "location_summary": "Birmingham, Alabama • Sedona, Arizona • Jonesboro, Arkansas + 98 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Sedona",
          "state": "Arizona"
        },
        {
          "city": "Jonesboro",
          "state": "Arkansas"
        },
        {
          "city": "Alhambra",
          "state": "California"
        },
        {
          "city": "Bakersfield",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00938652"
    }
  ]
}