ER-positive Breast Cancer

13

Review clinical trials related to ER-positive Breast Cancer. Use filters to narrow results by trial status, phase, treatment, biological sex and sponsor.

Condition / disease
Location
Status: Recruiting

Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer

This phase 3 clinical trial compares the efficacy and safety of palazestrant with ribociclib to letrozole and ribociclib in women and men who have not received prior systemic anti-cancer treatment for advanced breast cancer.

Participants needed: 1,000
Trial details
Phase: Phase 3Age: 18+Biological sex: AllType: InterventionalSponsor: Olema Pharmaceuticals, Inc.Updated: Jun 16, 2026Locations: 150
Eligibility criteria

Adult female or male participants. [+7]

Disease recurrence during adjuvant endocrine therapy [+5]

Status: Recruiting

Elacestrant for Treating ER+/HER2- Breast Cancer Patients With ctDNA Relapse (TREAT ctDNA)

This is an international, multi-center, randomised, open label, superiority phase III trial of elacestrant vs standard endocrine therapy in patients with ER+/HER2- breast cancer and ctDNA relapse. During the ctDNA screening phase, patients will be tested at different timepoints to detect the presence of ctDNA in their blood. Patients who are found to be ctDNA-positive and have no evidence of distant metastasis, will be randomised 1:1 between standard endocrine treatment (the same they were receiving when tested ctDNA positive) versus elacestrant, provided they meet all eligibility criteria. After completion of the protocol treatment period, treatment will be left at the discretion of the treating physician.

Participants needed: 220
Trial details
Phase: Phase 3Age: 18+Biological sex: AllType: InterventionalSponsor: European Organisation for Research and Treatment of Cancer - EORTCUpdated: May 15, 2026Locations: 109
Eligibility criteria

ER-positive defined as ≥ 10% of cells staining positive for ER or Allred proport... [+22]

Suspected recurrent disease or known conflicts with the inclusion and exclusion... [+29]

Status: Recruiting

Trial of Pre-operative Neratinib and Endocrine Therapy With Trastuzumab in ER-Positive, HER-2 Positive Breast Cancers

Patient will be treated with neratinib, an aromatase inhibitor and trastuzumab for 24 weeks prior to surgery, following an initial 3 weeks of neratinib alone, aromatase inhibitor alone or the combination of neratinib and an aromatase inhibitor. A breast biopsy will be performed prior to Day 1 of week 4 of treatment. Following surgery, patients will receive standard of care HER2-directed and endocrine therapy at the treating physician's discretion.

Participants needed: 30
Trial details
Phase: Phase 2Age: 18+Biological sex: AllType: InterventionalSponsor: Ruth O'ReganUpdated: Apr 8, 2026Locations: 4
Eligibility criteria

Written informed consent and HIPAA authorization for release of personal health... [+24]

Locally advanced or inflammatory breast cancer. NOTE: Locally advanced is define... [+15]

Status: Recruiting

Elacestrant + Everolimus in Patients ER+/HER2-, ESR1mut, Advanced Breast Cancer Progressing to ET and CDK4/6i.

This trial will study a type of advanced breast cancer (ABC) defined as endocrine receptor (ER)-positive/human epidermal growth factor receptor 2(HER2)-negative and estrogen receptor 1 (ESR1)-mutated. Patients will be treated with elacestrant, a compound that acts as a selective estrogen receptor degrader, and everolimus (or placebo), a kinase inhibitor indicated for the treatment of postmenopausal women with advanced hormone receptor-positive, HER2-negative breast cancer. The main purpose of the study is to analyze the efficacy (to find out how effective a treatment is) of elacestrant plus everolimus therapy in patients who have ER-positive/HER2-negative, ESR1-mutated, ABC progressing to endocrine therapy and cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. The efficacy of elacestrant plus everolimus combination will be determined by assessing the period from elacestrant plus everolimus (or placebo) treatment initiation until to the first occurrence of disease progression, unacceptable toxicity, death, or discontinuation from the study treatment for any other reason, whichever occurs first, defined as progression free survival. Rigorous eligibility criteria based on specific co-morbidities and clinicopathologic features of their disease have been designed to minimize the risk of patients participating in this study. The anticipated favorable clinical benefits of elacestrant combined with everolimus are projected to outweigh the risks of this treatment. This study will be performed in full compliance with International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and all applicable local Good Clinical Practice (GCP) and regulations.

Participants needed: 240
Trial details
Phase: Phase 3Age: 18+Biological sex: AllType: InterventionalSponsor: MedSIRUpdated: Apr 3, 2026Locations: 99
Eligibility criteria

Patient must be capable to understand the purpose of the study and have signed w... [+19]

Resolution of all acute toxic effects of prior anti-cancer therapy to grade ≤ 1... [+28]

Status: Not yet recruiting

Supporting Health Including Endocrine Treatment for Long Duration

This research is being done to pilot an intervention which aims to test a new web- and mobile application ("app")-based supportive care tool (SHIELD portal) and to assess the feasibility of enrolling female breast cancer patients with hormone receptor-positive disease long-term endocrine treatment.

Participants needed: 30
Trial details
Age: 18-49Biological sex: FemaleType: InterventionalSponsor: Dana-Farber Cancer InstituteUpdated: Mar 19, 2026Locations: 1
Eligibility criteria

Female [+8]

Individuals under age 18 or over age 50 at initial breast cancer diagnosis [+5]

Status: Recruiting

OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer

This phase 3 clinical trial compares the safety and efficacy of palazestrant (OP-1250) to the standard-of-care options of fulvestrant or an aromatase inhibitor in women and men with breast cancer whose disease has advanced on one endocrine therapy in combination with a CDK4/6 inhibitor.

Participants needed: 510
Trial details
Phase: Phase 3Age: 18+Biological sex: AllType: InterventionalSponsor: Olema Pharmaceuticals, Inc.Updated: Mar 13, 2026Locations: 233
Eligibility criteria

Adult female or male participants. [+7]

Symptomatic visceral disease, imminent organ failure, or any other reason that m... [+6]

Status: Recruiting

Fulvestrant+Abemaciclib With Run-In of Fulvestrant in Er-Positive, Her2-Negative Metastatic Breast Cancer

The study will investigate if CDK4/6 inhibitor holiday will reset the cell cycle process to respond to the combination of fulvestrant and abemaciclib, and this approach may represent an effective therapeutic strategy to manage such patients.

Participants needed: 28
Trial details
Phase: Phase 2Age: 18+Biological sex: AllType: InterventionalSponsor: The Methodist Hospital Research InstituteUpdated: Jan 28, 2026Locations: 1
Eligibility criteria

Male or Female >18 years of age on the day of informed consent signing. [+24]

Currently participating and receiving study therapy or has participated in a stu... [+20]

Status: Recruiting

Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer

This is a Phase 1b open-label, 2-part study in 3 treatment groups. The 3 treatment groups are as follows: Treatment Group 1: Palazestrant (OP-1250) in combination with ribociclib (KISQALI®, Novartis Pharmaceuticals Corporation). Treatment Group 2: Palazestrant (OP-1250) in combination with alpelisib (PIQRAY®, Novartis Pharmaceuticals Corporation). Treatment Group 3: Palazestrant (OP-1250) in combination with everolimus. Treatment Group 4: Palazestrant (OP-1250) in combination with atirmociclib.

Participants needed: 190
Trial details
Phase: Phase 1Age: 18+Biological sex: AllType: InterventionalSponsor: Olema Pharmaceuticals, Inc.Updated: Oct 22, 2025Locations: 16
Eligibility criteria

Female or male aged >18 years. [+8]

Prior or concurrent malignancy whose natural history or treatment may interfere... [+13]

Status: Recruiting

DATO-BASE: DATOpotamab-deruxtecan for Breast Cancer Brain metAstaSEs

The purpose of this study is to test the safety and effectiveness of the study drug datopotamab deruxtecan in participants with metastatic breast cancer that has spread to the brain. The name of the study drug used in this research study is: Datopotamab deruxtecan (a type of antibody-drug conjugate)

Participants needed: 58
Trial details
Phase: Phase 2Age: 18+Biological sex: AllType: InterventionalSponsor: Sarah Sammons, MDUpdated: Jul 30, 2025Locations: 3
Eligibility criteria

Metastatic breast cancer that is pathologically confirmed to be HER2-negative ac... [+20]

Visceral crisis or impending visceral crisis [+22]

Status: Recruiting

Role of the Immune Environment in Response to Therapy in Breast Cancer

This is an observational case-control study of tissues collected from women with ER+HER2- breast cancers. The immune environments of these cancers will be compared to triple negative and HER2+ breast cancers. No randomization or changes to standard of care treatment will occur as part of the study.

Participants needed: 300
Trial details
Age: 18+Biological sex: FemaleType: ObservationalSponsor: Abramson Cancer Center at Penn MedicineUpdated: Jul 8, 2025Locations: 1
Eligibility criteria

Not listed

Status: Recruiting

PRE-I-SPY Phase I/Ib Oncology Platform Program

I-SPY Phase I/Ib (I-SPY-P1) is an open-label, multisite platform study designed to evaluate single agents or combinations in a metastatic treatment setting that may be relevant for breast cancer patients with the overall goal of moving promising drug regimens into the I-SPY 2 SMART Design Trial (NCT01042379) and/or other oncology-based trials in a timely manner.

Participants needed: 124
Trial details
Phase: Phase 1Age: 18+Biological sex: AllType: InterventionalSponsor: QuantumLeap Healthcare CollaborativeUpdated: Apr 4, 2025Locations: 7
Eligibility criteria

GIC1: The participant must have ability to understand and willingness to provide... [+15]

chemotherapy or investigational agents, 3 weeks [+17]

Status: Recruiting

To Identify Primary Resistance to CDK4/6 Inhibitors in Breast Cancer

This is a multi-center biomarkers study aiming to prospectively collect biological samples from patients with ER+ and HER2-negative metastatic breast cancer, who are candidate to first-line treatment with an aromatase inhibitor and a CDK4/6 inhibitor as per standard clinical practice. Blood and tissue samples will be collected for biomarker analysis, including thymidine kinase1 activity, gene expression signatures and circulating tumor DNA.

Participants needed: 150
Trial details
Biological sex: FemaleType: ObservationalSponsor: Fondazione Sandro PitiglianiUpdated: Feb 26, 2025Locations: 1Duration: 5 Years
Eligibility criteria

Women aged 18 years or older, with a diagnosis of metastatic breast cancer [+6]

Patients with metastatic disease isolated to the central nervous system (CNS) wi... [+1]

Status: Recruiting

Immunotherapy, Hormone Therapy, and AKT Inhibitor for Premenopausal ER Positive MBC

This is an open-label randomized phase II study in estrogen receptor positive locally advanced or metastatic breast cancer patients. The main inclusion population are either luminal subtype B by PAM50 analysis or failed less than 2 lines of hormonal therapy for locally advanced or metastatic breast cancer. The subjects have to be premenopausal or perimenopausal and are not allowed to receive any systemic chemotherapy for their locally advanced or metastatic breast cancer. Eligible subjects will be randomized into goserelin/ fulvestrant/ durvalumab (Arm A), goserelin/ fulvestrant/ capivasertib/ durvalumab (Arm B), or goserelin/ fulvestrant/ capivasertib (Arm C) at a 1:1:1 ratio. The primary endpoint is objective response rate (ORR) of the whole other three arm compared to historical goserelin/ fulvestrantcontrol arm. The major secondary endpoint will be progression-free survival or ORR compared among different treatment arms.

Participants needed: 42
Trial details
Phase: Phase 2Age: 20+Biological sex: FemaleType: InterventionalSponsor: National Taiwan University HospitalUpdated: Jun 10, 2024Locations: 1
Eligibility criteria

A histological confirmed ER positive (>1%) invasive breast cancer. [+19]

Prior therapy with capivasertib, fulvestrant, anti-PD1 or anti-PDL1 immunotherap... [+37]