{ "api_version": "1", "request": { "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=letrozole+2.5+mg", "query": { "intervention": "letrozole 2.5 mg" }, "page_size": 10 }, "pagination": { "page": 1, "page_size": 10, "total_count": 132, "total_pages": 14, "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=letrozole+2.5+mg&page=2&page_size=10", "previous_page_url": null }, "source": "remote", "last_synced_at": "2026-09-22T12:57:54.669Z", "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": "NCT00134680", "title": "Letrozole, Herceptin in Her2neu +, Estrogen Receptor [ER] and/or Progesterone Receptor [PR] Positive, MBC", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Metastatic Breast Cancer" ], "interventions": [ { "name": "Letrozole", "type": "DRUG" }, { "name": "Trastuzumab", "type": "DRUG" } ], "intervention_types": [ "DRUG" ], "sponsor": "Duke 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": 33, "start_date": "2000-01", "completion_date": "2005-07", "has_results": false, "last_update_posted_date": "2014-09-16", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 4, "location_summary": "Washington D.C., District of Columbia • Boston, Massachusetts • St Louis, Missouri + 1 more", "locations": [ { "city": "Washington D.C.", "state": "District of Columbia" }, { "city": "Boston", "state": "Massachusetts" }, { "city": "St Louis", "state": "Missouri" }, { "city": "Durham", "state": "North Carolina" } ], "official_url": "https://clinicaltrials.gov/study/NCT00134680" }, { "nct_id": "NCT04852887", "title": "De-Escalation of Breast Radiation Trial for Hormone Sensitive, HER-2 Negative, Oncotype Recurrence Score Less Than or Equal to 18 Breast Cancer (DEBRA)", "overall_status": "RECRUITING", "study_type": "INTERVENTIONAL", "phases": [ "PHASE3" ], "conditions": [ "Stage I Breast Cancer" ], "interventions": [ { "name": "Radiation and Endocrine Therapy (Tamoxifen, Anastrozol, Letrozole, Exemestane)", "type": "OTHER" }, { "name": "Endocrine Therapy (Tamoxifen, Anastrozol, Letrozole, Exemestane)", "type": "DRUG" } ], "intervention_types": [ "OTHER", "DRUG" ], "sponsor": "NRG Oncology", "sponsor_class": "OTHER", "healthy_volunteers": false, "eligibility": { "minimum_age": "50 Years", "maximum_age": "70 Years", "sex": "ALL", "summary": "50 Years to 70 Years" }, "enrollment_count": 1670, "start_date": "2021-06-23", "completion_date": "2041-07", "has_results": false, "last_update_posted_date": "2026-04-23", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 812, "location_summary": "Birmingham, Alabama • Mobile, Alabama • Kingman, Arizona + 553 more", "locations": [ { "city": "Birmingham", "state": "Alabama" }, { "city": "Mobile", "state": "Alabama" }, { "city": "Kingman", "state": "Arizona" }, { "city": "Phoenix", "state": "Arizona" }, { "city": "Phoenix", "state": "Arizona" } ], "official_url": "https://clinicaltrials.gov/study/NCT04852887" }, { "nct_id": "NCT00090857", "title": "Letrozole in Preventing Breast Cancer in Postmenopausal Women", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Breast Cancer" ], "interventions": [ { "name": "Letrozole", "type": "DRUG" }, { "name": "Placebo", "type": "OTHER" } ], "intervention_types": [ "DRUG", "OTHER" ], "sponsor": "Dana-Farber Cancer Institute", "sponsor_class": "OTHER", "healthy_volunteers": false, "eligibility": { "minimum_age": "35 Years", "maximum_age": "120 Years", "sex": "FEMALE", "summary": "35 Years to 120 Years · Female only" }, "enrollment_count": 49, "start_date": "2002-02", "completion_date": "2013-03", "has_results": true, "last_update_posted_date": "2018-03-30", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 5, "location_summary": "Boston, Massachusetts • Philadelphia, Pennsylvania • Houston, Texas", "locations": [ { "city": "Boston", "state": "Massachusetts" }, { "city": "Boston", "state": "Massachusetts" }, { "city": "Boston", "state": "Massachusetts" }, { "city": "Philadelphia", "state": "Pennsylvania" }, { "city": "Houston", "state": "Texas" } ], "official_url": "https://clinicaltrials.gov/study/NCT00090857" }, { "nct_id": "NCT06979596", "title": "A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)", "overall_status": "RECRUITING", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Malignant Neoplasm" ], "interventions": [ { "name": "Opevesostat", "type": "DRUG" }, { "name": "Fludrocortisone/ Fludrocortisone acetate", "type": "DRUG" }, { "name": "Dexamethasone/Dexamethasone acetate", "type": "DRUG" }, { "name": "Rescue Medications", "type": "DRUG" }, { "name": "Fulvestrant", "type": "DRUG" }, { "name": "Exemestane", "type": "DRUG" }, { "name": "Megestrol acetate/Medroxyprogesterone acetate", "type": "DRUG" }, { "name": "Tamoxifen", "type": "DRUG" }, { "name": "Letrozole", "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": 250, "start_date": "2025-08-11", "completion_date": "2027-11-04", "has_results": false, "last_update_posted_date": "2026-08-28", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 10, "location_summary": "Anchorage, Alaska • Miami Beach, Florida • Shreveport, Louisiana + 6 more", "locations": [ { "city": "Anchorage", "state": "Alaska" }, { "city": "Miami Beach", "state": "Florida" }, { "city": "Shreveport", "state": "Louisiana" }, { "city": "Hastings", "state": "Nebraska" }, { "city": "Hackensack", "state": "New Jersey" } ], "official_url": "https://clinicaltrials.gov/study/NCT06979596" }, { "nct_id": "NCT01491737", "title": "A Study of Pertuzumab in Combination With Trastuzumab Plus an Aromatase Inhibitor in Participants With Metastatic Human Epidermal Growth Factor Receptor 2 (HER2)-Positive and Hormone Receptor-Positive Advanced Breast Cancer", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Breast Cancer" ], "interventions": [ { "name": "Pertuzumab", "type": "DRUG" }, { "name": "Trastuzumab", "type": "DRUG" }, { "name": "Aromatase Inhibitor", "type": "DRUG" }, { "name": "Induction Chemotherapy", "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": 258, "start_date": "2012-02-17", "completion_date": "2019-11-14", "has_results": true, "last_update_posted_date": "2020-10-28", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 21, "location_summary": "Birmingham, Alabama • Chandler, Arizona • Hot Springs, Arkansas + 17 more", "locations": [ { "city": "Birmingham", "state": "Alabama" }, { "city": "Chandler", "state": "Arizona" }, { "city": "Hot Springs", "state": "Arkansas" }, { "city": "Bakersfield", "state": "California" }, { "city": "Denver", "state": "Colorado" } ], "official_url": "https://clinicaltrials.gov/study/NCT01491737" }, { "nct_id": "NCT00997373", "title": "Letrozole as a Treatment of Endometrial Cancer", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "NA" ], "conditions": [ "Endometrial Carcinoma" ], "interventions": [ { "name": "Letrozole", "type": "DRUG" } ], "intervention_types": [ "DRUG" ], "sponsor": "University of California, Davis", "sponsor_class": "OTHER", "healthy_volunteers": false, "eligibility": { "minimum_age": "40 Years", "maximum_age": null, "sex": "FEMALE", "summary": "40 Years and older · Female only" }, "enrollment_count": 43, "start_date": "2009-10", "completion_date": "2013-09", "has_results": true, "last_update_posted_date": "2017-05-30", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 2, "location_summary": "Sacramento, California", "locations": [ { "city": "Sacramento", "state": "California" }, { "city": "Sacramento", "state": "California" } ], "official_url": "https://clinicaltrials.gov/study/NCT00997373" }, { "nct_id": "NCT01919229", "title": "A Pharmacodynamics Pre-surgical Study of LEE011 in Early Breast Cancer Patients (MONALEESA-1)", "overall_status": "TERMINATED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Early Breast Cancer" ], "interventions": [ { "name": "LEE011 (ribociclib)", "type": "DRUG" }, { "name": "letrozole", "type": "DRUG" } ], "intervention_types": [ "DRUG" ], "sponsor": "Novartis Pharmaceuticals", "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": 14, "start_date": "2013-10", "completion_date": "2014-09", "has_results": true, "last_update_posted_date": "2016-01-01", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 4, "location_summary": "Fayetteville, Arkansas • Los Angeles, California • Boston, Massachusetts + 1 more", "locations": [ { "city": "Fayetteville", "state": "Arkansas" }, { "city": "Los Angeles", "state": "California" }, { "city": "Boston", "state": "Massachusetts" }, { "city": "Houston", "state": "Texas" } ], "official_url": "https://clinicaltrials.gov/study/NCT01919229" }, { "nct_id": "NCT00696072", "title": "Randomized Phase II Trial of Letrozole With or Without Dasatinib as First and Second-line Treatment for Hormone Receptor-positive, HER2-negative Post-menopausal Breast Cancer That is Unresectable, Locally Recurrent or Metastatic", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Metastatic Breast Cancer" ], "interventions": [ { "name": "Dasatinib", "type": "DRUG" }, { "name": "Letrozole", "type": "DRUG" } ], "intervention_types": [ "DRUG" ], "sponsor": "Bristol-Myers Squibb", "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": 120, "start_date": "2008-08", "completion_date": "2014-06", "has_results": true, "last_update_posted_date": "2016-06-13", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 27, "location_summary": "Sedona, Arizona • Tucson, Arizona • Denver, Colorado + 22 more", "locations": [ { "city": "Sedona", "state": "Arizona" }, { "city": "Tucson", "state": "Arizona" }, { "city": "Denver", "state": "Colorado" }, { "city": "Hudson", "state": "Florida" }, { "city": "Carmel", "state": "Indiana" } ], "official_url": "https://clinicaltrials.gov/study/NCT00696072" }, { "nct_id": "NCT05206448", "title": "Randomized Controlled Trial of Combined Letrozole and Clomid (CLC II) Versus Letrozole Alone for Women With Anovulation", "overall_status": "ACTIVE_NOT_RECRUITING", "study_type": "INTERVENTIONAL", "phases": [ "PHASE4" ], "conditions": [ "Polycystic Ovary Syndrome", "PCOS", "Infertility" ], "interventions": [ { "name": "Letrozole", "type": "DRUG" }, { "name": "Clomiphene Citrate", "type": "DRUG" } ], "intervention_types": [ "DRUG" ], "sponsor": "Rachel Mejia", "sponsor_class": "OTHER", "healthy_volunteers": false, "eligibility": { "minimum_age": "18 Years", "maximum_age": "40 Years", "sex": "FEMALE", "summary": "18 Years to 40 Years · Female only" }, "enrollment_count": 190, "start_date": "2020-10-26", "completion_date": "2025-12", "has_results": true, "last_update_posted_date": "2025-04-15", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 4, "location_summary": "Davenport, Iowa • Iowa City, Iowa • West Des Moines, Iowa + 1 more", "locations": [ { "city": "Davenport", "state": "Iowa" }, { "city": "Iowa City", "state": "Iowa" }, { "city": "West Des Moines", "state": "Iowa" }, { "city": "Madison", "state": "Wisconsin" } ], "official_url": "https://clinicaltrials.gov/study/NCT05206448" }, { "nct_id": "NCT00238316", "title": "Letrozole in Preventing Breast Cancer in Postmenopausal Women Who Are at Increased Risk for Breast Cancer Due to High Breast Density", "overall_status": "COMPLETED", "study_type": "INTERVENTIONAL", "phases": [ "PHASE2" ], "conditions": [ "Breast Cancer" ], "interventions": [ { "name": "letrozole", "type": "DRUG" }, { "name": "Placebo", "type": "OTHER" } ], "intervention_types": [ "DRUG", "OTHER" ], "sponsor": "NCIC Clinical Trials Group", "sponsor_class": "NETWORK", "healthy_volunteers": false, "eligibility": { "minimum_age": null, "maximum_age": "120 Years", "sex": "FEMALE", "summary": "Up to 120 Years · Female only" }, "enrollment_count": 68, "start_date": "2000-12-05", "completion_date": "2009-02-10", "has_results": false, "last_update_posted_date": "2020-04-02", "last_synced_at": "2026-09-22T12:57:54.669Z", "location_count": 2, "location_summary": "Boston, Massachusetts", "locations": [ { "city": "Boston", "state": "Massachusetts" }, { "city": "Boston", "state": "Massachusetts" } ], "official_url": "https://clinicaltrials.gov/study/NCT00238316" } ] }