| Not Yet Recruiting | Supporting Health Including Endocrine Treatment for Long Duration NCT07482384 | Dana-Farber Cancer Institute | N/A |
| Withdrawn | A Randomised Trial Comparing Trastuzumab Deruxtecan to CDK4/6 Inhibitors in Non-luminal A, ER-positive/HER2-lo NCT06585969 | Danish Breast Cancer Cooperative Group | Phase 3 |
| Recruiting | Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer NCT07085767 | Olema Pharmaceuticals, Inc. | Phase 3 |
| Active Not Recruiting | A Phase 1 Study of ATV-1601 in Patients With Advanced Cancer That Have AKT1 E17K Mutations NCT07038369 | Atavistik Bio, Inc | Phase 1 |
| Recruiting | Elacestrant + Everolimus in Patients ER+/HER2-, ESR1mut, Advanced Breast Cancer Progressing to ET and CDK4/6i. NCT06382948 | MedSIR | Phase 3 |
| Recruiting | DATO-BASE: DATOpotamab-deruxtecan for Breast Cancer Brain metAstaSEs NCT06176261 | Sarah Sammons, MD | Phase 2 |
| Recruiting | Elacestrant for Treating ER+/HER2- Breast Cancer Patients With ctDNA Relapse (TREAT ctDNA) NCT05512364 | European Organisation for Research and Treatment of Cancer - EORTC | Phase 3 |
| Recruiting | OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer NCT06016738 | Olema Pharmaceuticals, Inc. | Phase 3 |
| Withdrawn | Fulvestrant + Neratinib In Breast Cancer NCT04901299 | Massachusetts General Hospital | Phase 2 |
| Active Not Recruiting | Levels of Circulating Tumor DNA as a Predictive Marker for Early Switch in Treatment for Patients With Metasta NCT05826964 | University of Miami | Phase 2 |
| Completed | Umbrella Trial of Subtype-Targeted Therapies in ER+/HER2- Breast Cancer NCT05101564 | Jennifer Lee Caswell-Jin | Phase 2 |
| Recruiting | PRE-I-SPY Phase I/Ib Oncology Platform Program NCT05868226 | QuantumLeap Healthcare Collaborative | Phase 1 |
| Recruiting | Immunotherapy, Hormone Therapy, and AKT Inhibitor for Premenopausal ER Positive MBC NCT05720260 | National Taiwan University Hospital | Phase 2 |
| Completed | Neoadjuvant Treatment of Locally-advanced Breast Cancer Patients With Ribociclib and Letrozole NCT05163106 | University Hospital, Akershus | Phase 2 |
| Recruiting | Role of the Immune Environment in Response to Therapy in Breast Cancer NCT05396612 | Abramson Cancer Center at Penn Medicine | — |
| Recruiting | Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmocicli NCT05508906 | Olema Pharmaceuticals, Inc. | Phase 1 |
| Recruiting | Trial of Pre-operative Neratinib and Endocrine Therapy With Trastuzumab in ER-Positive, HER-2 Positive Breast NCT04886531 | Ruth O'Regan | Phase 2 |
| Completed | Study to Evaluate the Extended Overall Survival (OS) Data From PARSIFAL Study (The PARSIFAL-LONG Study) NCT06525675 | MedSIR | — |
| Completed | D4 Choline Breast PET/CT NCT04276272 | Imperial College London | — |
| Terminated | Onapristone and Fulvestrant for ER+ HER2- Metastatic Breast Cancer After Endocrine Therapy and CDK4/6 Inhibito NCT04738292 | University of Wisconsin, Madison | Phase 2 |
| Active Not Recruiting | Phase II Study of Neoadjuvant ArOMatase Inhibitor Therapy for ER+ Breast Cancer (NAOMI) NCT04568616 | Dartmouth-Hitchcock Medical Center | Phase 2 |
| Recruiting | Fulvestrant+Abemaciclib With Run-In of Fulvestrant in Er-Positive, Her2-Negative Metastatic Breast Cancer NCT05305924 | The Methodist Hospital Research Institute | Phase 2 |
| Terminated | Study of Infigratinib in Combination With Tamoxifen in Hormone Receptor Positive, HER2 Negative, FGFR Altered NCT04504331 | Jennifer Lee Caswell-Jin | Phase 1 |
| Terminated | A Study of Zilovertamab Vedotin (MK-2140/VLS-101) in Participants With Solid Tumors (MK-2140-002) NCT04504916 | VelosBio Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) | Phase 2 |
| Recruiting | To Identify Primary Resistance to CDK4/6 Inhibitors in Breast Cancer NCT04660435 | Fondazione Sandro Pitigliani | — |
| Unknown | A Study of Neoadjuvant SHR6390 in Combination With Anastrozole, Pyrotinib, and Trastuzumab in Patients With ER NCT04236310 | Ruijin Hospital | Phase 2 |
| Terminated | Neoadjuvant Hormonal Therapy Combined With Chemoimmunotherapy NCT02345772 | Western Regional Medical Center | Phase 1 / Phase 2 |
| Withdrawn | AUY922 With Lapatinib and Letrozole for ER+ HER2+ Advanced Breast Cancer NCT01361945 | Texas Tech University Health Sciences Center, El Paso | Phase 1 / Phase 2 |
| Completed | An Observational Study to Assess Response to Tamoxifen in Breast Cancer Patients NCT00965939 | Vlaamse Vereniging voor Obstetrie en Gynaecologie | — |