{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Onapristone",
    "query": {
      "intervention": "Onapristone"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 6,
    "total_pages": 1,
    "next_page_url": null,
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-02T21:39:34.310Z",
  "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": "NCT04872608",
      "title": "A Study of Letrozole, Palbociclib, and Onapristone ER in People With Metastatic Breast Cancer",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Metastatic Breast Cancer",
        "Unresectable Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Palbociclib",
          "type": "DRUG"
        },
        {
          "name": "Onapristone ER",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Memorial Sloan Kettering Cancer 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": 0,
      "start_date": "2021-09-09",
      "completion_date": "2023-04-25",
      "has_results": false,
      "last_update_posted_date": "2023-04-28",
      "last_synced_at": "2026-09-02T21:39:34.310Z",
      "location_count": 1,
      "location_summary": "Harrison, New York",
      "locations": [
        {
          "city": "Harrison",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04872608"
    },
    {
      "nct_id": "NCT04719273",
      "title": "Onapristone and Anastrozole for the Treatment of Refractory Hormone Receptor Positive Endometrial Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Refractory Endometrial Adenocarcinoma",
        "Refractory Endometrial Carcinoma",
        "Refractory Endometrial Clear Cell Adenocarcinoma",
        "Refractory Endometrial Endometrioid Adenocarcinoma",
        "Refractory Endometrial Mixed Cell Adenocarcinoma",
        "Refractory Endometrial Serous Adenocarcinoma",
        "Refractory Endometrial Undifferentiated Carcinoma"
      ],
      "interventions": [
        {
          "name": "Extended-release Onapristone",
          "type": "DRUG"
        },
        {
          "name": "Anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Quality-of-Life Assessment",
          "type": "OTHER"
        },
        {
          "name": "Questionnaire Administration",
          "type": "OTHER"
        },
        {
          "name": "Estrogen Receptor Positive (Positive Estrogen Receptor; ESR Positive; ESR1 Positive; ER Positive; Estrogen Receptor Alpha Positive)",
          "type": "DIAGNOSTIC_TEST"
        },
        {
          "name": "Progesterone Receptor Positive ( PGR Positive; PR Positive)",
          "type": "DIAGNOSTIC_TEST"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER",
        "DIAGNOSTIC_TEST"
      ],
      "sponsor": "Thomas Jefferson 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": 14,
      "start_date": "2021-01-28",
      "completion_date": "2025-12-17",
      "has_results": true,
      "last_update_posted_date": "2026-07-17",
      "last_synced_at": "2026-09-02T21:39:34.310Z",
      "location_count": 2,
      "location_summary": "Abington, Pennsylvania • Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Abington",
          "state": "Pennsylvania"
        },
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04719273"
    },
    {
      "nct_id": "NCT03909152",
      "title": "A Study of Onapristone ER Alone Or In Combination With Anastrozole in Gynecologic Cancers That Respond to Progesterone",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Granulosa Cell Ovarian Cancer",
        "Low Grade Serous Ovarian/ Primary Peritoneal Cancer",
        "Endometrioid Endometrial Cancer"
      ],
      "interventions": [
        {
          "name": "Onapristone ER",
          "type": "DRUG"
        },
        {
          "name": "Onapristone ER + Anastrozole",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Memorial Sloan Kettering Cancer 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": 34,
      "start_date": "2019-05-02",
      "completion_date": "2024-09-03",
      "has_results": true,
      "last_update_posted_date": "2025-07-28",
      "last_synced_at": "2026-09-02T21:39:34.310Z",
      "location_count": 8,
      "location_summary": "Basking Ridge, New Jersey • Middletown, New Jersey • Montvale, New Jersey + 5 more",
      "locations": [
        {
          "city": "Basking Ridge",
          "state": "New Jersey"
        },
        {
          "city": "Middletown",
          "state": "New Jersey"
        },
        {
          "city": "Montvale",
          "state": "New Jersey"
        },
        {
          "city": "Commack",
          "state": "New York"
        },
        {
          "city": "Harrison",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03909152"
    },
    {
      "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": "2026-09-02T21:39:34.310Z",
      "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": "NCT06938711",
      "title": "A Rollover Protocol of Elacestrant, in Combination With Onapristone, for Patients With ER+, PR+, HER2- Advanced or Metastatic Breast Cancer",
      "overall_status": "WITHDRAWN",
      "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": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 0,
      "start_date": "2023-06",
      "completion_date": "2023-12",
      "has_results": false,
      "last_update_posted_date": "2025-04-22",
      "last_synced_at": "2026-09-02T21:39:34.310Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06938711"
    },
    {
      "nct_id": "NCT04738292",
      "title": "Onapristone and Fulvestrant for ER+ HER2- Metastatic Breast Cancer After Endocrine Therapy and CDK4/6 Inhibitors (The SMILE Study)",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "ER-positive Breast Cancer",
        "HER2-negative Breast Cancer",
        "Metastatic Cancer"
      ],
      "interventions": [
        {
          "name": "Onapristone",
          "type": "DRUG"
        },
        {
          "name": "Fulvestrant",
          "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": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 11,
      "start_date": "2021-10-05",
      "completion_date": "2023-05-15",
      "has_results": true,
      "last_update_posted_date": "2024-05-03",
      "last_synced_at": "2026-09-02T21:39:34.310Z",
      "location_count": 2,
      "location_summary": "Madison, Wisconsin • Milwaukee, Wisconsin",
      "locations": [
        {
          "city": "Madison",
          "state": "Wisconsin"
        },
        {
          "city": "Milwaukee",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04738292"
    }
  ]
}