{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Initiation+of+letrozole",
    "query": {
      "intervention": "Initiation of letrozole"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 8,
    "total_pages": 1,
    "next_page_url": null,
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-15T02:32:02.181Z",
  "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": "NCT04931342",
      "title": "A Study Evaluating the Efficacy and Safety of Biomarker-Driven Therapies in Patients With Persistent or Recurrent Rare Epithelial Ovarian Tumors",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Ovarian Cancer"
      ],
      "interventions": [
        {
          "name": "Ipatasertib",
          "type": "DRUG"
        },
        {
          "name": "Cobimetinib",
          "type": "DRUG"
        },
        {
          "name": "Trastuzumab Emtansine",
          "type": "DRUG"
        },
        {
          "name": "Atezolizumab",
          "type": "DRUG"
        },
        {
          "name": "Bevacizumab",
          "type": "DRUG"
        },
        {
          "name": "Paclitaxel",
          "type": "DRUG"
        },
        {
          "name": "Giredestrant",
          "type": "DRUG"
        },
        {
          "name": "Abemaciclib",
          "type": "DRUG"
        },
        {
          "name": "Inavolisib",
          "type": "DRUG"
        },
        {
          "name": "Palbociclib",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Olaparib",
          "type": "DRUG"
        },
        {
          "name": "Luteinizing Hormone-Releasing Hormone (LHRH) Agonists",
          "type": "DRUG"
        },
        {
          "name": "Cyclophosphamide",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Hoffmann-La Roche",
      "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": 176,
      "start_date": "2021-10-07",
      "completion_date": "2028-05-30",
      "has_results": false,
      "last_update_posted_date": "2026-09-10",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 8,
      "location_summary": "San Francisco, California • St Louis, Missouri • Charlotte, North Carolina + 5 more",
      "locations": [
        {
          "city": "San Francisco",
          "state": "California"
        },
        {
          "city": "St Louis",
          "state": "Missouri"
        },
        {
          "city": "Charlotte",
          "state": "North Carolina"
        },
        {
          "city": "Columbus",
          "state": "Ohio"
        },
        {
          "city": "Oklahoma City",
          "state": "Oklahoma"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04931342"
    },
    {
      "nct_id": "NCT01937052",
      "title": "Johns Hopkins Breast Cancer Program Hormone Therapy Longitudinal Database",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Sample collection",
          "type": "OTHER"
        },
        {
          "name": "Patient-reported outcomes",
          "type": "BEHAVIORAL"
        }
      ],
      "intervention_types": [
        "OTHER",
        "BEHAVIORAL"
      ],
      "sponsor": "Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 329,
      "start_date": "2012-05-09",
      "completion_date": "2024-11-25",
      "has_results": false,
      "last_update_posted_date": "2024-12-13",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 1,
      "location_summary": "Baltimore, Maryland",
      "locations": [
        {
          "city": "Baltimore",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01937052"
    },
    {
      "nct_id": "NCT07225790",
      "title": "Emulation of the MONARCH-3 Trial Using Specialty Oncology Electronic Health Records Databases",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Advanced Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Initiation of abemaciclib plus letrozole/anastrozole",
          "type": "DRUG"
        },
        {
          "name": "Initiation of letrozole/anastrozole",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": null,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 3883,
      "start_date": "2025-11-03",
      "completion_date": "2026-01-31",
      "has_results": false,
      "last_update_posted_date": "2026-05-12",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07225790"
    },
    {
      "nct_id": "NCT06075953",
      "title": "DCIS: RECAST Trial Ductal Carcinoma In Situ: Re-Evaluating Conditions for Active Surveillance Suitability as Treatment",
      "overall_status": "RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Ductal Carcinoma in Situ"
      ],
      "interventions": [
        {
          "name": "Tamoxifen",
          "type": "DRUG"
        },
        {
          "name": "Exemestane",
          "type": "DRUG"
        },
        {
          "name": "Letrozole",
          "type": "DRUG"
        },
        {
          "name": "Anastrazole",
          "type": "DRUG"
        },
        {
          "name": "Testosterone + Anastrazole",
          "type": "DRUG"
        },
        {
          "name": "Elacestrant",
          "type": "DRUG"
        },
        {
          "name": "Z-endoxifen",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "QuantumLeap Healthcare Collaborative",
      "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": 400,
      "start_date": "2024-02-17",
      "completion_date": "2033-11",
      "has_results": false,
      "last_update_posted_date": "2026-07-21",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 28,
      "location_summary": "Berkeley, California • Duarte, California • Irvine, California + 21 more",
      "locations": [
        {
          "city": "Berkeley",
          "state": "California"
        },
        {
          "city": "Duarte",
          "state": "California"
        },
        {
          "city": "Irvine",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "San Francisco",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT06075953"
    },
    {
      "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": "2026-09-15T02:32:02.181Z",
      "location_count": 1,
      "location_summary": "Miami, Florida",
      "locations": [
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05826964"
    },
    {
      "nct_id": "NCT00984399",
      "title": "Serum Estradiol Levels In Postmenopausal Women With Breast Cancer Receiving Adjuvant Aromatase Inhibitors and Vaginal Estrogen",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Atrophic Vaginitis",
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Vagifem® (vaginal 17β-estradiol) questionnaire & menopause symptom checklist",
          "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": 31,
      "start_date": "2009-09-22",
      "completion_date": "2024-05-13",
      "has_results": true,
      "last_update_posted_date": "2025-12-09",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 5,
      "location_summary": "Basking Ridge, New Jersey • Commack, New York • New York, New York + 2 more",
      "locations": [
        {
          "city": "Basking Ridge",
          "state": "New Jersey"
        },
        {
          "city": "Commack",
          "state": "New York"
        },
        {
          "city": "New York",
          "state": "New York"
        },
        {
          "city": "Rockville Centre",
          "state": "New York"
        },
        {
          "city": "Sleepy Hollow",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00984399"
    },
    {
      "nct_id": "NCT07178743",
      "title": "Emulation of the PALOMA-2 Trial",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Advanced Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Initiation of palbociclib plus letrozole",
          "type": "DRUG"
        },
        {
          "name": "Initiation of letrozole",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "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": 6097,
      "start_date": "2025-07-14",
      "completion_date": "2026-03-01",
      "has_results": false,
      "last_update_posted_date": "2026-05-12",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07178743"
    },
    {
      "nct_id": "NCT07274709",
      "title": "Emulation of the MONALEESA-2 Trial Using Specialty Oncology Electronic Health Records Databases",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Advanced Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Initiation of ribociclib",
          "type": "DRUG"
        },
        {
          "name": "Initiation of letrozole",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Shirley Vichy Wang",
      "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": 2495,
      "start_date": "2025-09-07",
      "completion_date": "2026-01-01",
      "has_results": false,
      "last_update_posted_date": "2026-05-12",
      "last_synced_at": "2026-09-15T02:32:02.181Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07274709"
    }
  ]
}