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ClinicalTrials.gov 423 recruiting now early-phase tilt #1 of 28,963 conditions

Breast Cancer: early-phase trial registry

423 of 1,251 indexed Breast Cancer trials are currently recruiting, with more weight in Phase 1-2.

Corpus placement: #1 of 28,963 conditions by registered trial count.

1,251 US clinical trials · 423 currently recruiting · #1 of 28,963 conditions by registered trial count

Breast Cancer: 1,251 US clinical trials tracked, 423 recruiting.

Breast Cancer is the subject of 1,251 registered US clinical trials on ClinicalTrials.gov, 423 of them currently open to new participants. 120 are in Phase 3-4 (later-stage) and 491 in Phase 1-2 (earlier-stage). The most active sponsor is Memorial Sloan Kettering Cancer Center, running 98 of these trials.

Open enrollment, early-phase tilt

Breast Cancer has 1,251 registered US clinical trials, 423 of them open to new participants right now, about 34% of the total.

423
recruiting participants now
34%
of trials open to enrollment
120
in Phase 3-4 (later-stage)
98
top sponsor: Memorial Sloan Kettering Cancer Center

Corpus placement: #1 of 28,963 conditions by registered trial count on ClinicalTrials.gov-derived indexes. Registry reference only, not medical advice.

Key findings

What ClinicalTrials.gov does not surface for Breast Cancer on its own pages , computed from the registry mirror as of 2026-07-11. Each line carries its own denominator so it can be quoted as it stands.

  1. Breast Cancer is recruiting below its size-band peers.

    423 of 1,251 indexed trials (33.8%) are open to enrollment, against a 37.2% average across 135 conditions with 100+ trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

  2. Sponsorship of Breast Cancer trials is spread across many organizations.

    Memorial Sloan Kettering Cancer Center accounts for 98 of 1,251 trials (7.8%). 367 distinct sponsors appear on at least one study for this condition label.

  3. Typical Breast Cancer enrolment sits around 90 participants.

    Median target enrolment is 90 among the 1,225 trials that report a genuine target (sentinel values excluded). 630 of those (51.4%) plan for fewer than 100 participants.

  4. Breast Cancer research is mostly interventional.

    1,015 interventional and 236 observational studies make up this index (81.1% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 1235Phase 2256Phase 3100Phase 420

Open and recent trials

1,251 total, page 9 of 26

RECRUITING Early Phase 1 20 participants

FES BPET-DBT in Newly Diagnosed Breast Cancer

Abramson Cancer Center at Penn Medicine

NCT05659797

RECRUITING Phase 2 20 participants

Anastrazole, Fulvestrant & Abemaciclib for HR+HER2- Metastatic Breast Cancer

University of California, Irvine

NCT05524584

RECRUITING Phase 1 20 participants

Phase Ib Study of Axatilimab in Combination With Olaparib in BRCA1/2 and PALB2- Associated Metastatic HER2-negative Breast Cancer

Dana-Farber Cancer Institute

NCT06488378

RECRUITING Early Phase 1 20 participants

Bortezomib Followed by Pembrolizumab and Cisplatin in metTNBC

Baylor Research Institute

NCT04265872

RECRUITING Early Phase 1 20 participants

Comparison of CE-DBT and MRI in Patients With Known Breast Lesions

UNC Lineberger Comprehensive Cancer Center

NCT05754749

RECRUITING NA 20 participants

Preoperative Nicotine Cessation for Women With Breast Cancer Recommended for Reconstruction

University of Florida

NCT06461650

RECRUITING Phase 1 20 participants

Study of Psilocybin Assisted Psychotherapy to Address Fear of Recurrence

University of Colorado, Denver

NCT06430541

RECRUITING Phase 1 20 participants

Study to Evaluate Biomarkers and Safety of Dapagliflozin Concomitant with Neoadjuvant Therapy

Yale University

NCT05989347

RECRUITING NA 20 participants

Dissemination of BREASTChoice AIM1-B

UNC Lineberger Comprehensive Cancer Center

NCT07396766

RECRUITING NA 20 participants

Impact of Intermittent Fasting on Biomarkers of Inflammation and Health-Related Quality of Life: A Feasibility Trial for Women With HR+/HER2- Early Breast Cancer

Medical College of Wisconsin

NCT06106477

RECRUITING NA 18 participants

SABER Study for Selected Early Stage Breast Cancer

University of Miami

NCT04360330

RECRUITING Phase 1 18 participants

A Study of BRIA-OTS Cellular Immunotherapy in Metastatic Recurrent Breast Cancer

BriaCell Therapeutics Corporation

NCT06471673

RECRUITING Early Phase 1 16 participants

Personalized Dendritic Cell Vaccine Pilot for High Risk TNBC After Neoadjuvant Therapy

H. Lee Moffitt Cancer Center and Research Institute

NCT06435351

RECRUITING NA 16 participants

Investigating the Metabolic Pathways in Hormone Receptor Positive/HER2 Negative Breast Cancer

Rutgers, The State University of New Jersey

NCT05736367

RECRUITING Phase 1 15 participants

RADIANT: Pre-op Radiation With Abemaciclib and Letrozole

Mridula George, MD

NCT06139107

RECRUITING NA 15 participants

NearWave Optical Molecular Monitoring

Indiana University

NCT06744465

RECRUITING 15 participants

Prospective Study of EXErcise Regimens After Treatment for Breast Cancer for Hypertrophy and Conditioning

Allegheny Singer Research Institute (also known as Allegheny Health Network Research Institute)

NCT07023887

RECRUITING Phase 2 13 participants

Evaluation of PSMA in HER2- AR+ Metastatic Breast Cancer

University of Wisconsin, Madison

NCT04573231

RECRUITING Phase 1 11 participants

Brodalumab in the Treatment of Immune-Related Adverse Events

Brian Henick, MD

NCT06673329

RECRUITING 10 participants

Ovarian-Sparing Adaptive Radiotherapy in Young Adult Women

Washington University School of Medicine

NCT06904365

RECRUITING Early Phase 1 10 participants

Positron Emission Tomography (PET) Imaging With Zirconium-89 (89Zr)-Trastuzumab for Prediction of HER2 Targeted Therapy Effectiveness

University of Alabama at Birmingham

NCT03321045

RECRUITING NA 10 participants

Feasibility Study for the SIRA-1000, SIRA® RFA Electrosurgical Device as an Adjunct to Breast Conserving Surgery

Innoblative Designs

NCT07206121

RECRUITING Phase 2 8 participants

Biomarkers to Detect Endocrine Therapy Resistance

University of Wisconsin, Madison

NCT06067503

ACTIVE NOT RECRUITING NA 21,081 participants

Germline Alterations of Tumor Susceptibility Genes in New York Cancer Patients

Memorial Sloan Kettering Cancer Center

NCT00579514

ACTIVE NOT RECRUITING 13,320 participants

Clinical Significance of Germline BRCA Mutations

Memorial Sloan Kettering Cancer Center

NCT00579488

ACTIVE NOT RECRUITING NA 8,000 participants

Salud en Mis Manos - Breast and Cervical Cancer Prevention and Early Detection - Expansion 2

The University of Texas Health Science Center, Houston

NCT06082882

ACTIVE NOT RECRUITING NA 7,920 participants

Increasing Screening for Cancer Using EHR-Nudges Replication

Abramson Cancer Center at Penn Medicine

NCT06995703

ACTIVE NOT RECRUITING 7,000 participants

Collection of Tissue, Blood, and Cells to Be Used For Studying the Causes, Prevention, Diagnosis, and Treatment of Breast Cancer

Memorial Sloan Kettering Cancer Center

NCT00588029

ACTIVE NOT RECRUITING Phase 3 5,796 participants

PALbociclib CoLlaborative Adjuvant Study

Alliance Foundation Trials

NCT02513394

ACTIVE NOT RECRUITING Phase 3 5,637 participants

Endocrine Therapy With or Without Abemaciclib (LY2835219) Following Surgery in Participants With Breast Cancer

Eli Lilly and Company

NCT03155997

ACTIVE NOT RECRUITING 4,000 participants

The Breast Program - Translational Cancer Resource

Abramson Cancer Center at Penn Medicine

NCT02798341

ACTIVE NOT RECRUITING Phase 3 3,966 participants

Letrozole in Treating Postmenopausal Women Who Have Received Hormone Therapy for Hormone Receptor-Positive Breast Cancer

NSABP Foundation

NCT00382070

ACTIVE NOT RECRUITING 3,465 participants

Breast Cancer Index (BCI) Registry

Biotheranostics

NCT04875351

ACTIVE NOT RECRUITING Phase 3 3,294 participants

S0221 Adjuvant Doxorubicin, Cyclophosphamide, and Paclitaxel in Treating Patients With Breast Cancer

SWOG Cancer Research Network

NCT00070564

ACTIVE NOT RECRUITING NA 2,500 participants

Early Point-of-Service Social and Behavioral Determinants of Health (SBDOH) Screening and Enhanced Navigation on Care Delivery for Patients With Breast Cancer

Abramson Cancer Center at Penn Medicine

NCT06019988

ACTIVE NOT RECRUITING NA 2,450 participants

The Engaging Primary Care in Cancer Survivorship (EPICS) Study

Kaiser Permanente

NCT04745754

ACTIVE NOT RECRUITING Phase 3 2,354 participants

Higher Per Daily Treatment-Dose Radiation Therapy or Standard Per Daily Treatment Radiation Therapy in Treating Patients With Early-Stage Breast Cancer That Was Removed by Surgery

Radiation Therapy Oncology Group

NCT01349322

ACTIVE NOT RECRUITING 2,187 participants

MRI Background Parenchymal Enhancement as a Risk Factor for Breast Cancer: The IMAGINg and Epidemiology (IMAGINE) Study

Memorial Sloan Kettering Cancer Center

NCT02301767

ACTIVE NOT RECRUITING 2,000 participants

The OPBC-07/microNAC Study

University Hospital, Basel, Switzerland

NCT06529302

ACTIVE NOT RECRUITING Phase 3 1,939 participants

S1207 Hormone Therapy With or Without Everolimus in Treating Patients With Breast Cancer

SWOG Cancer Research Network

NCT01674140

ACTIVE NOT RECRUITING Phase 3 1,902 participants

A Phase III Randomised Study to Evaluate Dato-DXd and Durvalumab for Neoadjuvant/Adjuvant Treatment of Triple-Negative or Hormone Receptor-low/HER2-negative Breast Cancer

AstraZeneca

NCT06112379

ACTIVE NOT RECRUITING Phase 3 1,836 participants

Olaparib as Adjuvant Treatment in Patients With Germline BRCA Mutated High Risk HER2 Negative Primary Breast Cancer

AstraZeneca

NCT02032823

ACTIVE NOT RECRUITING 1,699 participants

Study of Radiation Exposure and Bilateral Breast Cancer

Memorial Sloan Kettering Cancer Center

NCT00903591

ACTIVE NOT RECRUITING NA 1,647 participants

Tomosynthesis vs. Contrast-Enhanced Mammography in Women With Personal History of Breast Cancer in Western Pennsylvania

Wendie Berg

NCT04085510

ACTIVE NOT RECRUITING Phase 1 1,410 participants

Phase I-II, FIH, TROP2 ADC, Advanced Unresectable/Metastatic Solid Tumors, Refractory to Standard Therapies (KL264-01)

Klus Pharma

NCT04152499

ACTIVE NOT RECRUITING 1,302 participants

The Young Women's Breast Cancer Study

Dana-Farber Cancer Institute

NCT01468246

ACTIVE NOT RECRUITING 1,275 participants

Genomic Structural Variation in Cancer Susceptibility

Memorial Sloan Kettering Cancer Center

NCT00996710

ACTIVE NOT RECRUITING Phase 3 1,240 participants

Study of Pembrolizumab (MK-3475) Versus Placebo in Combination With Neoadjuvant Chemotherapy & Adjuvant Endocrine Therapy in the Treatment of Early-Stage Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative (ER+/HER2-) Breast Cancer (MK-3475-756/KEYNOTE-756)

Merck Sharp & Dohme

NCT03725059

ACTIVE NOT RECRUITING NA 1,238 participants

Pragmatic Randomized Trial of Proton vs. Photon Therapy for Patients With Non-Metastatic Breast Cancer: A Radiotherapy Comparative Effectiveness (RADCOMP) Consortium Trial

Abramson Cancer Center at Penn Medicine

NCT02603341

ACTIVE NOT RECRUITING Phase 3 1,188 participants

A Study Evaluating the Efficacy and Safety of Adjuvant Atezolizumab or Placebo and Trastuzumab Emtansine for Participants With HER2-Positive Breast Cancer at High Risk of Recurrence Following Preoperative Therapy

Hoffmann-La Roche

NCT04873362

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Phase Distribution

PhaseTrial count
Phase 1 235
Phase 2 256
Phase 3 100
Phase 4 20

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

What is open for Breast Cancer right now

423 recruiting of 1,251 indexed (34% open).

Phase mix: 120 late (III/IV) vs 491 early (I/II) (early-phase heavy).

Top sponsor: Memorial Sloan Kettering Cancer Center (98 trials), 9 others listed. 50 shown below, recruiting first. #1 of 28,963 conditions by registered trial count.

How open-enrollment share is computed

Open share is recruiting_count divided by trial_count for this condition label in the public registry export. Status can change between pulls; treat the figure as a snapshot of research attention, not treatment availability.

Frequently Asked Questions

How many clinical trials are there for Breast Cancer?

PlainTrial tracks 1,251 US clinical trials for Breast Cancer, of which 423 are currently recruiting participants. Data sourced from ClinicalTrials.gov.

How do I find a recruiting trial for 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.

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.

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.

Verify with NIH →

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, the data changelog, or report a data error.