{"id":"administration-of-letrozole","safety":{"commonSideEffects":[{"rate":"19-29","effect":"Hot flashes"},{"rate":"19-25","effect":"Arthralgia/joint pain"},{"rate":"13-19","effect":"Fatigue"},{"rate":"7-13","effect":"Headache"},{"rate":"9-13","effect":"Nausea"},{"rate":null,"effect":"Osteoporosis/bone loss"},{"rate":null,"effect":"Elevated cholesterol"}]},"_chembl":{"chemblId":"CHEMBL1444","moleculeType":"Small molecule","molecularWeight":"285.31"},"_dailymed":null,"mechanism":{"_ai_source":"claude-haiku-4.5","explanation":"Letrozole selectively inhibits the aromatase enzyme (CYP19A1), which catalyzes the final step of estrogen biosynthesis in peripheral tissues. By reducing estrogen availability, it suppresses the growth of hormone receptor-positive breast cancer cells that depend on estrogen signaling. This mechanism is particularly effective in postmenopausal women where peripheral aromatization is the primary source of estrogen.","oneSentence":"Letrozole is an aromatase inhibitor that blocks the conversion of androgens to estrogen, reducing circulating estrogen levels in postmenopausal women.","_ai_confidence":"high"},"_scrapedAt":"2026-03-28T00:44:37.534Z","_scrapedBy":"cloudflare-swarm","_wikipedia":null,"indications":{"approved":[{"name":"Hormone receptor-positive breast cancer in postmenopausal women (adjuvant and metastatic settings)"},{"name":"Extended adjuvant therapy following tamoxifen in early-stage breast cancer"},{"name":"First-line treatment of advanced breast cancer"}]},"trialDetails":[{"nctId":"NCT07391774","phase":"PHASE3","title":"Testing Whether Hormone Therapy With Ribociclib is as Effective as Chemotherapy Followed by Hormone Therapy With Ribociclib for the Treatment of High Anatomic Stage Breast Cancer With Low Recurrence Risk, The RxFINE-Low Trial","status":"NOT_YET_RECRUITING","sponsor":"National Cancer Institute (NCI)","startDate":"2026-07-07","conditions":"Anatomic Stage II Breast Cancer AJCC v8, Anatomic Stage IIIA Breast Cancer AJCC v8, Anatomic Stage IIIC Breast Cancer AJCC v8","enrollment":1978},{"nctId":"NCT00310180","phase":"PHASE3","title":"Hormone Therapy With or Without Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Negative Breast Cancer (The TAILORx Trial)","status":"ACTIVE_NOT_RECRUITING","sponsor":"National Cancer Institute (NCI)","startDate":"2006-04-07","conditions":"Breast Adenocarcinoma, Hormone Receptor Positive, Stage IA Breast Cancer AJCC v7","enrollment":10273},{"nctId":"NCT07492641","phase":"PHASE3","title":"BGB-43395 Plus Letrozole Versus CDK4/6i Plus Letrozole for Patients With Advanced or Metastatic HR+/HER2- Breast Cancer Who Have Not Received Prior Treatment for Advanced or Metastatic Disease","status":"NOT_YET_RECRUITING","sponsor":"BeOne Medicines","startDate":"2026-05-11","conditions":"HR+/HER2- Breast Cancer","enrollment":1056},{"nctId":"NCT05467891","phase":"PHASE2","title":"Ribociclib And Endocrine Treatment of Physician's Choice for Locoregional Recurrent, Resected Hormone Receptor Positive HER2 Negative Breast Cancer","status":"RECRUITING","sponsor":"Oana Danciu","startDate":"2022-09-13","conditions":"Locoregional Recurrence, Hormone Receptor-positive Breast Cancer, HER2-negative Breast Cancer","enrollment":200},{"nctId":"NCT06239376","phase":"NA","title":"Artificial Cycle With or Without GnRH Agonist Pre-treatment for Frozen Embryo Transfer in Adenomyosis Patients","status":"RECRUITING","sponsor":"Mỹ Đức Hospital","startDate":"2024-02-19","conditions":"Adenomyosis, IVF, Frozen Embryo Transfer","enrollment":222},{"nctId":"NCT07174336","phase":"PHASE3","title":"A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA)","status":"RECRUITING","sponsor":"Eli Lilly and Company","startDate":"2025-12-22","conditions":"Breast Neoplasms, Neoplasm Metastasis","enrollment":920},{"nctId":"NCT06072781","phase":"PHASE3","title":"A Study of Avutometinib (VS-6766) + Defactinib (VS-6063) in Recurrent Low-Grade Serous Ovarian Cancer","status":"RECRUITING","sponsor":"Verastem, Inc.","startDate":"2024-03-18","conditions":"Low Grade Serous Ovarian Cancer","enrollment":270},{"nctId":"NCT06075953","phase":"PHASE2","title":"DCIS: RECAST Trial Ductal Carcinoma In Situ: Re-Evaluating Conditions for Active Surveillance Suitability as Treatment","status":"RECRUITING","sponsor":"QuantumLeap Healthcare Collaborative","startDate":"2024-02-17","conditions":"Ductal Carcinoma in Situ","enrollment":400},{"nctId":"NCT07085767","phase":"PHASE3","title":"Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer","status":"RECRUITING","sponsor":"Olema Pharmaceuticals, Inc.","startDate":"2025-11-03","conditions":"Breast Cancer, Locally Advanced Breast Cancer, Metastatic Breast Cancer","enrollment":1000},{"nctId":"NCT03424005","phase":"PHASE1, PHASE2","title":"A Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Patients With Metastatic or Locally Advanced Breast Cancer","status":"RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2018-03-30","conditions":"Metastatic Breast Cancer","enrollment":792},{"nctId":"NCT03747042","phase":"PHASE2","title":"Letrozole in Post-Menopausal Patients With Operable Hormone-Sensitive Breast Cancer","status":"COMPLETED","sponsor":"University of Texas Southwestern Medical Center","startDate":"2018-11-27","conditions":"Breast Cancer Female","enrollment":61},{"nctId":"NCT06016738","phase":"PHASE3","title":"OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer","status":"RECRUITING","sponsor":"Olema Pharmaceuticals, Inc.","startDate":"2023-11-16","conditions":"Breast Cancer, Advanced Breast Cancer, Metastatic Breast Cancer","enrollment":510},{"nctId":"NCT01042379","phase":"PHASE2","title":"I-SPY TRIAL: Neoadjuvant and Personalized Adaptive Novel Agents to Treat Breast Cancer","status":"RECRUITING","sponsor":"QuantumLeap Healthcare Collaborative","startDate":"2010-03-01","conditions":"Breast Neoplasms, Breast Cancer, Breast Tumors","enrollment":5000},{"nctId":"NCT07319429","phase":"PHASE2, PHASE3","title":"Refining Fertility-sparing Treatment in Endometrial Carcinoma Based on Molecular Classification","status":"RECRUITING","sponsor":"Fudan University","startDate":"2026-01-25","conditions":"Endometrial Cancer, Fertility","enrollment":260},{"nctId":"NCT06380751","phase":"PHASE3","title":"Saruparib (AZD5305) Plus Camizestrant Compared With CDK4/6 Inhibitor Plus Endocrine Therapy or Plus Camizestrant in HR-Positive, HER2-Negative (IHC 0, 1+, 2+/ ISH Non-amplified), BRCA1, BRCA2, or PALB2m Advanced Breast Cancer","status":"RECRUITING","sponsor":"AstraZeneca","startDate":"2024-08-01","conditions":"Advanced Breast Cancer","enrollment":500},{"nctId":"NCT03006172","phase":"PHASE1","title":"To Evaluate the Safety, Tolerability, and Pharmacokinetics of Inavolisib Single Agent in Participants With Solid Tumors and in Combination With Endocrine and Targeted Therapies in Participants With Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Genentech, Inc.","startDate":"2016-12-13","conditions":"Breast Cancer, Solid Tumor","enrollment":200},{"nctId":"NCT04931342","phase":"PHASE2","title":"A Study Evaluating the Efficacy and Safety of Biomarker-Driven Therapies in Patients With Persistent or Recurrent Rare Epithelial Ovarian Tumors","status":"ACTIVE_NOT_RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2021-10-07","conditions":"Ovarian Cancer","enrollment":176},{"nctId":"NCT04393285","phase":"PHASE2","title":"Abemaciclib and Letrozole to Treat Endometrial Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Gynecologic Oncology Group","startDate":"2020-10-10","conditions":"Endometrial Cancer","enrollment":53},{"nctId":"NCT06979596","phase":"PHASE2","title":"A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)","status":"RECRUITING","sponsor":"Merck Sharp & Dohme LLC","startDate":"2025-08-11","conditions":"Malignant Neoplasm","enrollment":250},{"nctId":"NCT05700006","phase":"","title":"Pilot Observational Study Examining the Effect of Endocrine Therapy on Aging","status":"COMPLETED","sponsor":"University of Michigan","startDate":"2022-07-25","conditions":"Breast Neoplasm Female, Arthralgia, Aging","enrollment":94},{"nctId":"NCT06671912","phase":"PHASE3","title":"Testing Low Dose Tamoxifen for Invasive Breast Cancer, the (LoTam) Trial","status":"SUSPENDED","sponsor":"Alliance for Clinical Trials in Oncology","startDate":"2025-02-19","conditions":"Anatomic Stage 0 Breast Cancer AJCC v8, Anatomic Stage 1 Breast Cancer AJCC v8, Anatomic Stage IIA Breast Cancer AJCC v8","enrollment":1156},{"nctId":"NCT05894239","phase":"PHASE3","title":"A Study to Evaluate the Efficacy and Safety of Inavolisib in Combination With Phesgo Versus Placebo in Combination With Phesgo in Participants With PIK3CA-Mutated HER2-Positive Locally Advanced or Metastatic Breast Cancer","status":"RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2023-09-08","conditions":"Metastatic Breast Cancer","enrollment":230},{"nctId":"NCT03701334","phase":"PHASE3","title":"A Trial to Evaluate Efficacy and Safety of Ribociclib With Endocrine Therapy as Adjuvant Treatment in Patients With HR+/HER2- Early Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Novartis Pharmaceuticals","startDate":"2018-12-07","conditions":"Early Breast Cancer","enrollment":5101},{"nctId":"NCT04852887","phase":"PHASE3","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)","status":"RECRUITING","sponsor":"NRG Oncology","startDate":"2021-06-07","conditions":"Stage I Breast Cancer","enrollment":1670},{"nctId":"NCT06760637","phase":"PHASE3","title":"Study of PF-07220060 With Letrozole in Adults With HR-positive HER2-negative Breast Cancer Who Have Not Received Anticancer Treatment for Advanced/Metastatic Disease","status":"RECRUITING","sponsor":"Pfizer","startDate":"2025-01-06","conditions":"Breast Cancer","enrollment":1020},{"nctId":"NCT06179303","phase":"PHASE2","title":"Functional Imaging in Prediction of Response to Abemaciclib for Advanced Hormone Receptor-Positive, HER2-Negative Breast Cancer","status":"RECRUITING","sponsor":"University of Washington","startDate":"2024-07-22","conditions":"Anatomic Stage III Breast Cancer AJCC v8, Anatomic Stage IV Breast Cancer AJCC v8, Locally Advanced Unresectable HER2-Negative Breast Carcinoma","enrollment":60},{"nctId":"NCT07054190","phase":"PHASE2","title":"A Study to Test Inavolisib Treatments in Participants With Early-Stage, PIK3CA-Mutated Breast Cancer","status":"RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2025-09-09","conditions":"Breast Cancer","enrollment":60},{"nctId":"NCT02767661","phase":"PHASE3","title":"Metronomic Capecitabine Plus Aromatase Inhibitor for First Line Treatment in HR(+), Her2(-) Metastatic Breast Cancer","status":"COMPLETED","sponsor":"Sun Yat-sen University","startDate":"2017-07-19","conditions":"Breast Cancer","enrollment":263},{"nctId":"NCT03179904","phase":"PHASE2","title":"TVB-2640 and Trastuzumab With Paclitaxel or Endocrine Therapy for Treatment of HER2 Positive Metastatic Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Mayo Clinic","startDate":"2017-08-03","conditions":"Advanced Breast Carcinoma, HER2-Positive Breast Carcinoma, Anatomic Stage III Breast Cancer AJCC v8","enrollment":17},{"nctId":"NCT04059484","phase":"PHASE2","title":"Phase 2 Study of Amcenestrant (SAR439859) Versus Physician's Choice in Locally Advanced or Metastatic ER-positive Breast Cancer","status":"TERMINATED","sponsor":"Sanofi","startDate":"2019-10-22","conditions":"Breast Cancer Metastatic","enrollment":367},{"nctId":"NCT07425990","phase":"NA","title":"FET-LET-2x2: Clinical Pregnancy Rates After Frozen Embryo Transfer in Natural and Modified Natural Cycles","status":"NOT_YET_RECRUITING","sponsor":"University of Novi Sad","startDate":"2026-02","conditions":"Infertility Female, Frozen Embryo Transfer (FET)","enrollment":120},{"nctId":"NCT04961996","phase":"PHASE3","title":"A Study Evaluating the Efficacy and Safety of Adjuvant Giredestrant Compared With Physician's Choice of Adjuvant Endocrine Monotherapy in Participants With Estrogen Receptor-Positive, HER2-Negative Early Breast Cancer (lidERA Breast Cancer)","status":"ACTIVE_NOT_RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2021-08-27","conditions":"Early Breast Cancer","enrollment":4170},{"nctId":"NCT04546009","phase":"PHASE3","title":"A Study Evaluating the Efficacy and Safety of Giredestrant Combined With Palbociclib Compared With Letrozole Combined With Palbociclib in Participants With Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer (persevERA Breast Cancer)","status":"ACTIVE_NOT_RECRUITING","sponsor":"Hoffmann-La Roche","startDate":"2020-10-09","conditions":"Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer","enrollment":992},{"nctId":"NCT06127979","phase":"NA","title":"A Study of Changes in Ki67 Expression in People With Breast Cancer Receiving Endocrine Therapy Before Surgery","status":"RECRUITING","sponsor":"Memorial Sloan Kettering Cancer Center","startDate":"2023-11-06","conditions":"Breast Cancer","enrollment":42},{"nctId":"NCT02947685","phase":"PHASE3","title":"Randomized, Open Label, Clinical Study of the Targeted Therapy, Palbociclib, to Treat Metastatic Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Alliance Foundation Trials, LLC.","startDate":"2017-06-21","conditions":"HER-2 Positive Breast Cancer, Estrogen Receptor Positive Breast Cancer","enrollment":518},{"nctId":"NCT07071038","phase":"PHASE2","title":"Evaluating the Use of a Medication 'Switch' vs Guideline-directed Interventions for Relieving Side Effects of Aromatase Inhibitors Among Breast Cancer Patients","status":"RECRUITING","sponsor":"Dartmouth-Hitchcock Medical Center","startDate":"2025-10-17","conditions":"Breast Cancer, Adjuvant Treatment, Early Stage Breast Cancer","enrollment":62},{"nctId":"NCT02624973","phase":"PHASE2","title":"PErsonalized TREatment of High-risk MAmmary Cancer - the PETREMAC Trial","status":"ACTIVE_NOT_RECRUITING","sponsor":"Haukeland University Hospital","startDate":"2016-04-15","conditions":"Breast Cancer","enrollment":200},{"nctId":"NCT06585969","phase":"PHASE3","title":"A Randomised Trial Comparing Trastuzumab Deruxtecan to CDK4/6 Inhibitors in Non-luminal A, ER-positive/HER2-low Metastatic Breast Cancer","status":"WITHDRAWN","sponsor":"Danish Breast Cancer Cooperative Group","startDate":"2026-01-01","conditions":"Metastatic Breast Cancer, ER-positive Breast Cancer, Luminal B","enrollment":""},{"nctId":"NCT06366347","phase":"PHASE2","title":"ALPINE: Maintenance Letrozole/Abemaciclib","status":"RECRUITING","sponsor":"Dana-Farber Cancer Institute","startDate":"2024-09-25","conditions":"Endometrial Cancer, Recurrent Endometrial Cancer, TP53","enrollment":32},{"nctId":"NCT02499146","phase":"PHASE1","title":"Palbociclib Pharmacokinetics Study In Postmenopausal Chinese Women With ER (+), HER2 (-) Advanced Breast Cancer","status":"COMPLETED","sponsor":"Pfizer","startDate":"2015-09-11","conditions":"Advanced Breast Cancer","enrollment":26},{"nctId":"NCT07401381","phase":"PHASE1","title":"A Study to Compare the Steady-State Bioavailability of Injectable Letrozole SIE and Oral Letrozole in Post-Menopausal Women With Hormone Receptor Positive Early Breast Cancer","status":"NOT_YET_RECRUITING","sponsor":"Rovi Pharmaceuticals Laboratories","startDate":"2026-03","conditions":"Hormone Receptor Positive Early Breast Cancer","enrollment":120},{"nctId":"NCT05909397","phase":"PHASE3","title":"Vepdegestrant (ARV-471/PF-07850327) + Palbociclib vs Letrozole + Palbociclib in ER(+)/HER2(-) Advanced Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Pfizer","startDate":"2023-08-09","conditions":"Breast Cancer","enrollment":59},{"nctId":"NCT06143631","phase":"PHASE4","title":"Prescription of Letrozole for Uterine Myoma","status":"RECRUITING","sponsor":"University of California, San Francisco","startDate":"2024-07-24","conditions":"Leiomyoma, Uterine, Leiomyoma, Fibroid","enrollment":140},{"nctId":"NCT06394804","phase":"PHASE2","title":"A Study of Avutometinib, Defactinib, and Letrozole in People With Low-Grade Serous Ovarian Cancer","status":"RECRUITING","sponsor":"Memorial Sloan Kettering Cancer Center","startDate":"2024-04-29","conditions":"Low-Grade Serous Ovarian Cancer","enrollment":20},{"nctId":"NCT05161195","phase":"PHASE4","title":"Roll-over Study to Allow Continued Access to Ribociclib","status":"ACTIVE_NOT_RECRUITING","sponsor":"Novartis Pharmaceuticals","startDate":"2022-07-07","conditions":"Metastatic Breast Cancer","enrollment":134},{"nctId":"NCT06311383","phase":"","title":"A Non-interventional Study for Women With HR-positive, HER2-negative Locally Advanced or Metastatic Breast Cancer to Evaluate the Real-world Effectiveness of Treatment Algorithms Beginning With Ribociclib + AI/FUL, or With Endocrine Therapy or Chemotherapy as First Line Treatment","status":"COMPLETED","sponsor":"Novartis Pharmaceuticals","startDate":"2017-10-09","conditions":"Breast Cancer","enrollment":2610},{"nctId":"NCT07024173","phase":"PHASE3","title":"A Phase 3 Study of HRS-8080 Versus Treatment Chosen by Physicians in Locally Advanced and Metastatic Breast Cancer","status":"RECRUITING","sponsor":"Shandong Suncadia Medicine Co., Ltd.","startDate":"2025-07-23","conditions":"Locally Advanced Breast Cancer, Metastatic Breast Cancer","enrollment":240},{"nctId":"NCT05183828","phase":"PHASE4","title":"Effect of HSD3B1 (1245C) Gene Mutation on Treatment of Stage I-III Breast Cancer","status":"RECRUITING","sponsor":"University of Washington","startDate":"2022-01-23","conditions":"Anatomic Stage I Breast Cancer AJCC v8, Anatomic Stage II Breast Cancer AJCC v8, Anatomic Stage III Breast Cancer AJCC v8","enrollment":68},{"nctId":"NCT03879577","phase":"PHASE2","title":"Assessing the Response Rate of Neo-adjuvant Taxotere and Trastuzumab in Nigerian Women With Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"University of Chicago","startDate":"2019-11-25","conditions":"Breast Cancer, Breast Cancer Female, HER2-positive Breast Cancer","enrollment":53},{"nctId":"NCT06970912","phase":"PHASE2","title":"ctDNA-Guided De-Escalation of Adjuvant Chemotherapy With Dalpiciclib in HR-Positive/HER2-Negative Breast Cancer","status":"RECRUITING","sponsor":"Peking University People's Hospital","startDate":"2025-08-01","conditions":"Hormone Receptor-Positive Breast Cancer, High-risk Breast Cancer, Early-Stage Breast Cancer","enrollment":393},{"nctId":"NCT04568616","phase":"PHASE2","title":"Phase II Study of Neoadjuvant ArOMatase Inhibitor Therapy for ER+ Breast Cancer (NAOMI)","status":"ACTIVE_NOT_RECRUITING","sponsor":"Dartmouth-Hitchcock Medical Center","startDate":"2021-08-13","conditions":"Breast Cancer, ER Positive Breast Cancer","enrollment":178},{"nctId":"NCT04964934","phase":"PHASE3","title":"Phase III Study to Assess AZD9833+ CDK4/6 Inhibitor in HR+/HER2-MBC With Detectable ESR1m Before Progression (SERENA-6)","status":"ACTIVE_NOT_RECRUITING","sponsor":"AstraZeneca","startDate":"2021-06-30","conditions":"ER-Positive HER2-Negative Breast Cancer","enrollment":315},{"nctId":"NCT06001762","phase":"PHASE2","title":"TRADE: Dose Escalation Tolerability of Abemaciclib in HR+ HER2- Early Stage Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Dana-Farber Cancer Institute","startDate":"2023-10-05","conditions":"Breast Cancer, Early-stage Breast Cancer, High Risk Breast Carcinoma","enrollment":90},{"nctId":"NCT05860465","phase":"PHASE2, PHASE3","title":"Safety and Efficacy of SPH4336 in Combination With Endocrine Therapy in the Treatment of Locally Advanced or Metastatic Breast Cancer","status":"RECRUITING","sponsor":"Shanghai Pharmaceuticals Holding Co., Ltd","startDate":"2023-09-08","conditions":"Locally Advanced or Metastatic Breast Cancer","enrollment":254},{"nctId":"NCT05826964","phase":"PHASE2","title":"Levels of Circulating Tumor DNA as a Predictive Marker for Early Switch in Treatment for Patients With Metastatic (Stage IV) Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"University of Miami","startDate":"2023-06-12","conditions":"Breast Cancer, ER-positive Breast Cancer, HER2-negative Breast Cancer","enrollment":24},{"nctId":"NCT03056755","phase":"PHASE2","title":"Study Assessing the Efficacy and Safety of Alpelisib Plus Fulvestrant or Letrozole, Based on Prior Endocrine Therapy, in Patients With PIK3CA Mutant, HR+, HER2- Advanced Breast Cancer Who Have Progressed on or After Prior Treatments","status":"COMPLETED","sponsor":"Novartis Pharmaceuticals","startDate":"2017-08-29","conditions":"Breast Cancer","enrollment":383},{"nctId":"NCT05150652","phase":"PHASE2","title":"Neoadjuvant Endocrine Therapy in ER-positive, HER2-negative Early Stage Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Irada Ibrahim-zada","startDate":"2022-02-18","conditions":"Breast Cancer, HER2-negative Breast Cancer, Node-negative Breast Cancer","enrollment":8},{"nctId":"NCT06630325","phase":"PHASE2","title":"A Precision Medicine Approach (SMMART-ACT) for the Treatment of Patients With Advanced Sarcoma, Prostate, Breast, Ovarian or Pancreatic Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"OHSU Knight Cancer Institute","startDate":"2025-06-24","conditions":"Advanced Breast Carcinoma, Advanced Malignant Solid Neoplasm, Advanced Ovarian Carcinoma","enrollment":30},{"nctId":"NCT06974929","phase":"PHASE1, PHASE2","title":"A Clinical Study of HRS-6209 Combined With Other Treatment Regimens in Patients With Breast Cancer","status":"RECRUITING","sponsor":"Jiangsu HengRui Medicine Co., Ltd.","startDate":"2025-05-22","conditions":"Breast Cancer","enrollment":80},{"nctId":"NCT07305246","phase":"PHASE2","title":"Clinical Study of SHR-A1811 With or Without Letrozole in Neoadjuvant Therapy for Early-Stage HR-Positive, HER2-Low Breast Cancer","status":"NOT_YET_RECRUITING","sponsor":"First Hospital of China Medical University","startDate":"2025-12","conditions":"Breast Cancer","enrollment":120},{"nctId":"NCT03673124","phase":"PHASE2","title":"Ribociclib and Letrozole Treatment in Ovarian Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Gynecologic Oncology Group","startDate":"2019-05-20","conditions":"Low Grade Serous Carcinoma","enrollment":51},{"nctId":"NCT05069038","phase":"PHASE2","title":"Clinical Trial Assessing the Safety of Neoadjuvant Palbociclib in Combination With Endocrine Therapy","status":"ACTIVE_NOT_RECRUITING","sponsor":"University of Nebraska","startDate":"2022-03-02","conditions":"Breast Cancer","enrollment":51},{"nctId":"NCT07285382","phase":"PHASE2","title":"Different Doses of Dalpicicl Combined With Letrozole in the First-line Treatment of HR-positive, HER2-negative Advanced Breast Cancer","status":"RECRUITING","sponsor":"wanghaibo","startDate":"2025-06-25","conditions":"HR Positive HER2 Negative Advanced Breast Cancer","enrollment":120},{"nctId":"NCT04563507","phase":"PHASE2","title":"Combined Immunotherapies in Metastatic ER+ Breast Cancer","status":"RECRUITING","sponsor":"Weill Medical College of Cornell University","startDate":"2020-11-12","conditions":"Breast Cancer","enrollment":102},{"nctId":"NCT04603183","phase":"PHASE2","title":"ABemaciclib, ET ± paclItaxel in aGgressive HR+/HER2- MBC trIaL","status":"COMPLETED","sponsor":"MedSIR","startDate":"2021-06-02","conditions":"Breast Cancer Metastatic","enrollment":162},{"nctId":"NCT06706414","phase":"PHASE1, PHASE2","title":"NT-NOA - Novel Treatment of Some Men With Non-Obstructive Azoospermia","status":"ACTIVE_NOT_RECRUITING","sponsor":"Martin Blomberg Jensen","startDate":"2025-03-01","conditions":"Infertility, Male","enrollment":16},{"nctId":"NCT05226871","phase":"PHASE2","title":"Study for Participants Continuing From Pfizer-sponsored Palbociclib (a Study Medicine) Studies","status":"ACTIVE_NOT_RECRUITING","sponsor":"Pfizer","startDate":"2022-07-07","conditions":"Breast Cancer, Head and Neck Cancer","enrollment":35},{"nctId":"NCT06495164","phase":"","title":"A Real-life Study to Understand the Use and Effects of Palbociclib in US Patients With Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Pfizer","startDate":"2024-06-24","conditions":"Breast Cancer, Malignant Neoplasm of Breast","enrollment":1},{"nctId":"NCT01771458","phase":"PHASE2","title":"A Randomized Phase II Trial Comparing Therapy Based on Tumor Molecular Profiling Versus Conventional Therapy in Patients With Refractory Cancer","status":"COMPLETED","sponsor":"Institut Curie","startDate":"2012-10","conditions":"Reccurent/Metastatic Solid Tumor Disease","enrollment":742},{"nctId":"NCT05867251","phase":"PHASE1, PHASE2","title":"Study of AVZO-021 in Patients With Advanced Solid Tumors","status":"RECRUITING","sponsor":"Avenzo Therapeutics, Inc.","startDate":"2023-08-30","conditions":"Advanced Solid Tumor, HR+/HER2- Breast Cancer, HR+, HER2-, Advanced Breast Cancer","enrollment":430},{"nctId":"NCT05041842","phase":"PHASE2","title":"Treatment With Tucatinib in Patients With an Isolated Brain Progression of a Metastatic Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"UNICANCER","startDate":"2021-12-17","conditions":"Metastatic Breast Cancer With a Isolated Brain Progression","enrollment":53},{"nctId":"NCT06139107","phase":"PHASE1","title":"RADIANT: Pre-op Radiation With Abemaciclib and Letrozole","status":"RECRUITING","sponsor":"Mridula George, MD","startDate":"2024-08-22","conditions":"Breast Cancer","enrollment":15},{"nctId":"NCT02101788","phase":"PHASE2, PHASE3","title":"Trametinib in Treating Patients With Recurrent or Progressive Low-Grade Ovarian Cancer or Peritoneal Cavity Cancer","status":"COMPLETED","sponsor":"National Cancer Institute (NCI)","startDate":"2014-04-11","conditions":"Borderline Ovarian Serous Tumor, Micropapillary Serous Carcinoma, Ovarian Serous Adenocarcinoma","enrollment":260},{"nctId":"NCT04569747","phase":"PHASE2","title":"A Single Arm Phase II Study of ADjuvant Endocrine Therapy, Pertuzumab, and Trastuzumab for Patients With Anatomic Stage I Hormone Receptor-positive, HER2-positive Breast Cancer","status":"RECRUITING","sponsor":"Dana-Farber Cancer Institute","startDate":"2021-01-11","conditions":"HER2-positive Breast Cancer, Invasive Carcinoma of the Breast, Breast Cancer","enrollment":375},{"nctId":"NCT03671330","phase":"PHASE2","title":"Efficacy and Safety of Ribociclib in Pre- and Postmenopausal Chinese Women With HR Positive, HER2-negative, Advanced Breast Cancer.","status":"COMPLETED","sponsor":"Novartis Pharmaceuticals","startDate":"2018-08-29","conditions":"Breast Cancer","enrollment":327},{"nctId":"NCT02297438","phase":"PHASE3","title":"A Study Of Palbociclib (PD-0332991) + Letrozole VS. Placebo+ Letrozole For 1st Line Treatment Of Asian Postmenopausal Women With ER+/HER2- Advanced Breast Cancer [PALOMA-4]","status":"COMPLETED","sponsor":"Pfizer","startDate":"2015-03-23","conditions":"Breast Neoplasms","enrollment":340},{"nctId":"NCT04272801","phase":"PHASE2","title":"Pre-Operative Window of Adjuvant Endocrine Therapy to Inform RT Decisions in Older Women With Early-Stage Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Shayna Showalter, MD","startDate":"2020-04-07","conditions":"Breast Cancer Female","enrollment":84},{"nctId":"NCT04049227","phase":"EARLY_PHASE1","title":"Abemaciclib and Letrozole in Treating Patients With Endometrial Cancer","status":"COMPLETED","sponsor":"Northwestern University","startDate":"2019-08-12","conditions":"Endometrial Endometrioid Adenocarcinoma","enrollment":27},{"nctId":"NCT03822468","phase":"PHASE2","title":"Study of 2 Ribociclib Doses in Combination With Aromatase Inhibitors in Women With HR+, HER2- Advanced Breast Cancer","status":"COMPLETED","sponsor":"Novartis Pharmaceuticals","startDate":"2019-06-11","conditions":"Breast Cancer","enrollment":376},{"nctId":"NCT06361940","phase":"PHASE2","title":"Molecular Analyses to Predict Pathways of Endocrine Resistance Following Short Term Neoadjuvant Endocrine Treatment in Patients With Hormone Receptor-Positive HER2-negative Breast Cancer","status":"RECRUITING","sponsor":"Medical College of Wisconsin","startDate":"2024-09-30","conditions":"Breast Cancer","enrollment":100},{"nctId":"NCT07190443","phase":"PHASE3","title":"Adjuvant Abemaciclib for Locoregional Recurrence of HR-positive, HER2-negative Breast Cancer (JCOG2313, AURA)","status":"RECRUITING","sponsor":"Japanese Foundation for Cancer Research","startDate":"2025-02-07","conditions":"Breast Cancer, Locoregional Recurrence, Abemaciclib","enrollment":290},{"nctId":"NCT02562118","phase":"PHASE1, PHASE2","title":"Neoadjuvant Lenvatinib Combined With Letrozole in Hormone Receptor Positive Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"National University Hospital, Singapore","startDate":"2015-10-02","conditions":"Breast Cancer","enrollment":40},{"nctId":"NCT04158362","phase":"PHASE3","title":"Endocrine Therapy With Abemaciclib or Chemotherapy as Initial Metastatic Treatment in ER+/HER2- Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"UNICANCER","startDate":"2020-06-11","conditions":"Cancer Metastatic","enrollment":180},{"nctId":"NCT03283384","phase":"PHASE2","title":"Tailoring NEOadjuvant Therapy in Hormone Receptor Positive, HER2 Negative, Luminal Breast Cancer.","status":"ACTIVE_NOT_RECRUITING","sponsor":"Borstkanker Onderzoek Groep","startDate":"2019-06-15","conditions":"Breast Neoplasms","enrollment":100},{"nctId":"NCT07183787","phase":"PHASE2","title":"Letrozole vs Danazol for Endometriosis-Related Pain: Randomized Trial","status":"COMPLETED","sponsor":"Sidra Salman","startDate":"2019-04-10","conditions":"Endometriosis","enrollment":60},{"nctId":"NCT03425838","phase":"PHASE3","title":"Endocrine Therapy Plus CDK4/6 in First or Second Line for Hormone (SONIA) Receptor Positive Advanced Breast Cancer","status":"ACTIVE_NOT_RECRUITING","sponsor":"Borstkanker Onderzoek Groep","startDate":"2017-11-09","conditions":"Breast Neoplasm Female","enrollment":1050},{"nctId":"NCT07179939","phase":"PHASE2","title":"Maintenance Therapy in HER2-Positive Unresectable Locally Recurrent or Metastatic Breast Cancer: A Phase II Study","status":"NOT_YET_RECRUITING","sponsor":"Fudan University","startDate":"2025-09-10","conditions":"HER2-positive Breast Cancer","enrollment":288},{"nctId":"NCT04191382","phase":"PHASE2","title":"Phase 2 Window Study of SAR439859 (Amcenestrant) Versus Letrozole in Post-menopausal Patients With ER+, HER2- Pre-operative Post-menopausal Primary Breast Cancer","status":"TERMINATED","sponsor":"Sanofi","startDate":"2020-02-04","conditions":"Breast Cancer","enrollment":105},{"nctId":"NCT03778931","phase":"PHASE3","title":"Phase 3 Trial of Elacestrant Versus Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer","status":"COMPLETED","sponsor":"Stemline Therapeutics, Inc.","startDate":"2019-05-10","conditions":"Breast Cancer","enrollment":478},{"nctId":"NCT06145308","phase":"PHASE2","title":"Precision Treatment of Recurrent/Metastatic Salivary Gland Carcinoma Guided by Molecular Typing","status":"RECRUITING","sponsor":"Peking Union Medical College","startDate":"2023-08-15","conditions":"Salivary Gland Carcinoma, Precision Therapy","enrollment":39},{"nctId":"NCT04478266","phase":"PHASE3","title":"Amcenestrant (SAR439859) Plus Palbociclib as First Line Therapy for Patients With ER (+) HER2(-) Advanced Breast Cancer","status":"TERMINATED","sponsor":"Sanofi","startDate":"2020-10-14","conditions":"Breast Cancer","enrollment":1068},{"nctId":"NCT02958852","phase":"PHASE2","title":"A Clinical Trial to Compare Efficacy and Tolerability of Atorvastatin in Addition to Endocrine Treatment With Focus on Mechanisms of Resistance to Endocrine Treatment (Fulvestrant/Aromatase Inhibitors) in Patients With Advanced Breast Cancer","status":"COMPLETED","sponsor":"Lund University Hospital","startDate":"2025-01-02","conditions":"Breast Cancer","enrollment":126},{"nctId":"NCT07160855","phase":"PHASE4","title":"Letrozole Plus Misoprostol Versus Misoprostol Alone for Treating Women With Missed Miscarriage","status":"RECRUITING","sponsor":"Nishtar Medical University","startDate":"2025-05-13","conditions":"Miscarriage in First Trimester, Missed Miscarriage","enrollment":92},{"nctId":"NCT07153757","phase":"PHASE3","title":"De-escalation Therapy in Stage I ER-Positive Breast Cancer: A Non-Inferiority Trial","status":"NOT_YET_RECRUITING","sponsor":"Fudan University","startDate":"2025-09-01","conditions":"Breast Cancer Early Stage Breast Cancer (Stage 1-3)","enrollment":2934},{"nctId":"NCT04486352","phase":"PHASE1, PHASE2","title":"A Study of Targeted Agents for Patients With Recurrent or Persistent Endometrial Cancer","status":"RECRUITING","sponsor":"Alliance Foundation Trials, LLC.","startDate":"2021-10-20","conditions":"Endometrial Cancer","enrollment":148},{"nctId":"NCT06041204","phase":"NA","title":"Best Treatment for Women With Both (Polycystic Ovary Syndrome) PCOS and Subclinical Hypothyroidism","status":"RECRUITING","sponsor":"Muhamed Ahmed Abdelmoaty Muhamed Alhagrasy","startDate":"2021-05-06","conditions":"PCOS (Polycystic Ovary Syndrome) of Bilateral Ovaries, Subclinical Hypothyroidism, Female Infertility","enrollment":200},{"nctId":"NCT05900206","phase":"PHASE2","title":"Trastuzumab Deruxtecan Versus Standard Neoadjuvant Treatment for HER2-positive Breast Cancer","status":"RECRUITING","sponsor":"Karolinska University Hospital","startDate":"2023-10-26","conditions":"Breast Cancer","enrollment":370},{"nctId":"NCT05512364","phase":"PHASE3","title":"Elacestrant for Treating ER+/HER2- Breast Cancer Patients With ctDNA Relapse (TREAT ctDNA)","status":"RECRUITING","sponsor":"European Organisation for Research and Treatment of Cancer - EORTC","startDate":"2023-12-15","conditions":"ER-positive Breast Cancer, HER2-negative Breast Cancer, Stage IIB Breast Cancer","enrollment":220},{"nctId":"NCT05744687","phase":"PHASE2, PHASE3","title":"Phase II/III Study of SPH4336 Combined With Letrozole vs Placebo Combined With Letrozole in First-line Treatment of Breast Cancer","status":"RECRUITING","sponsor":"Shanghai Pharmaceuticals Holding Co., Ltd","startDate":"2023-04-24","conditions":"Locally Advanced or Metastatic Breast Cancer","enrollment":374},{"nctId":"NCT05316935","phase":"PHASE2, PHASE3","title":"GnRHa + Letrozole in Non-obese Progestin-insensitive Endometrial Cancer and Atypical Hyperplasia Patients","status":"RECRUITING","sponsor":"Xiaojun Chen","startDate":"2022-07-13","conditions":"Endometrial Neoplasms, Atypical Endometrial Hyperplasia, Progesterone Resistance","enrollment":80}],"_emaApprovals":[],"_faersSignals":[],"_approvalHistory":[],"publicationCount":1613,"rwe":[],"genericFilers":[],"relatedDrugs":[],"labelChanges":[],"biosimilarFilings":[],"pricing":[],"formularyStatus":[],"manufacturing":[],"companionDiagnostics":[],"competitors":[],"timeline":[],"patents":[],"ownershipHistory":[],"trials":[],"biosimilars":[],"latestUpdates":[],"references":[],"tags":[],"ecosystem":[],"genericManufacturerList":[],"offLabel":[],"developmentCodes":[],"aliases":["Oral administration of letrozole"],"phase":"phase_3","status":"active","brandName":"Administration of letrozole","genericName":"Administration of letrozole","companyName":"IVI Madrid","companyId":"ivi-madrid","modality":"Small molecule","firstApprovalDate":"","aiSummary":"Letrozole is an aromatase inhibitor that blocks the conversion of androgens to estrogen, reducing circulating estrogen levels in postmenopausal women. Used for Hormone receptor-positive breast cancer in postmenopausal women (adjuvant and metastatic settings), Extended adjuvant therapy following tamoxifen in early-stage breast cancer, First-line treatment of advanced breast cancer.","enrichmentLevel":3,"visitCount":0,"trialStats":{"total":0,"withResults":0},"verificationStatus":"verified","dataCompleteness":{"mechanism":true,"indications":true,"safety":true,"trials":true,"score":4}}