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ER Positive Breast Cancer clinical trials
7 of 11 indexed ER Positive Breast Cancer trials are currently recruiting.
11 US clinical trials · 7 currently recruiting
ER Positive Breast Cancer is the subject of 11 registered US clinical trials on ClinicalTrials.gov, 7 of them currently open to new participants. 2 are in Phase 3-4 (later-stage) and 8 in Phase 1-2 (earlier-stage). The most active sponsor is Olema Pharmaceuticals, running 3 of these trials.
The research picture
ER Positive Breast Cancer has 11 registered US clinical trials, 7 of them open to new participants right now, about 64% of the total.
- 7
- recruiting participants now
- 64%
- of trials open to enrollment
- 2
- in Phase 3–4 (later-stage)
- 3
- top sponsor: Olema Pharmaceuticals
Active & Recent Trials
11 total, page 1 of 1
Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer
Olema Pharmaceuticals
NCT07085767
OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer
Olema Pharmaceuticals
NCT06016738
Role of the Immune Environment in Response to Therapy in Breast Cancer
Abramson Cancer Center at Penn Medicine
NCT05396612
Phase 1b Study of OP-1250 (Palazestrant) in Combination With Ribociclib, Alpelisib, Everolimus, or Atirmociclib in ER+, HER2- Breast Cancer
Olema Pharmaceuticals
NCT05508906
DATO-BASE: DATOpotamab-deruxtecan for Breast Cancer Brain metAstaSEs
Sarah Sammons, MD
NCT06176261
Trial of Pre-operative Neratinib and Endocrine Therapy With Trastuzumab in ER-Positive, HER-2 Positive Breast Cancers
Ruth O'Regan
NCT04886531
Fulvestrant+Abemaciclib With Run-In of Fulvestrant in Er-Positive, Her2-Negative Metastatic Breast Cancer
The Methodist Hospital Research Institute
NCT05305924
Phase II Study of Neoadjuvant ArOMatase Inhibitor Therapy for ER+ Breast Cancer (NAOMI)
Dartmouth-Hitchcock Medical Center
NCT04568616
A Phase 1 Study of ATV-1601 in Patients With Advanced Cancer That Have AKT1 E17K Mutations
Atavistik Bio
NCT07038369
Levels of Circulating Tumor DNA as a Predictive Marker for Early Switch in Treatment for Patients With Metastatic (Stage IV) Breast Cancer
University of Miami
NCT05826964
Umbrella Trial of Subtype-Targeted Therapies in ER+/HER2- Breast Cancer
Jennifer Lee Caswell-Jin
NCT05101564
Phase Distribution
| Phase | Trial count |
|---|---|
| Phase 1 | 2 |
| Phase 2 | 6 |
| Phase 3 | 2 |
Top Sponsors
Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.
Reading the ER Positive Breast Cancer Trial Landscape
11 indexed ER Positive Breast Cancer studies · 7 recruiting (64%).
Phase mix: 2 late (III/IV) vs 8 early (I/II).
Top sponsor: Olema Pharmaceuticals (3 trials), 8 others listed. 11 shown below, recruiting first.
How to read this condition's trial landscape
That ratio is a useful proxy for activity level: a high share of recruiting studies often signals that research interest is current and that new enrollment opportunities are appearing, while a low share typically means the field is dominated by completed or follow-up work where most participant spots have already been filled. These counts reflect the public registry only and include studies at every stage of design, so they should be read as an index of research attention rather than as a measure of treatment availability.
Phase 1 and Phase 2 studies focus on early safety signals, dosing, and preliminary effect, while Phase 3 studies are typically the larger efficacy and safety trials submitted toward regulatory review, and Phase 4 studies follow approved interventions in real-world use. A condition weighted toward later phases often reflects a mature research pipeline with several interventions already close to or past approval, whereas a heavier early-phase tilt suggests the field is still exploring new mechanisms and candidate approaches.
All figures are derived from the public ClinicalTrials.gov dataset maintained by the National Library of Medicine and are reproduced here for reference. Inclusion of a trial, sponsor, or intervention on this page is neither an endorsement nor a recommendation, eligibility, protocol changes, and site-level status can shift frequently, so always verify current details on ClinicalTrials.gov and consult a qualified healthcare provider before acting on anything you see here.
Frequently Asked Questions
How many clinical trials are there for ER Positive Breast Cancer?
PlainTrial tracks 11 US clinical trials for ER Positive Breast Cancer, of which 7 are currently recruiting participants. Data sourced from ClinicalTrials.gov.
How do I find a recruiting trial for ER Positive Breast Cancer?
Use the trial list above filtered by "Recruiting" status, or visit our trial finder at /recruiting to search by condition and state. Always discuss trial participation with your healthcare provider before enrolling.
Is this data current?
Data is sourced from ClinicalTrials.gov and reflects our most recent data pull. Trial status may have changed since then. Always verify current information at ClinicalTrials.gov before making decisions about participation.
Related
Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from ClinicalTrials.gov (National Library of Medicine). Consult a qualified professional before making decisions based on this data.
Read our methodology - how this data is sourced, computed, and verified.
Source: ClinicalTrials.gov (NIH/NLM) ClinicalTrials.gov AACT registry · 2026 Trial counts and statuses sourced from ClinicalTrials.gov. Sponsor counts include both industry and federal/academic sponsors.
Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This page aggregates every registered trial for this condition, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.