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ClinicalTrials.gov 423 recruiting now early-phase tilt #1 of 28,707 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 28,707 conditions by registered trial count.

1,251 US clinical trials · 423 currently recruiting · #1 of 28,707 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.

Enrollment posture brief

Registry condition breast-cancer

OPEN 423 | RECR 34% | LATE 120 | EARLY 491 | RANK #1 | SPON 98

Nearest open-share peer: Refractory Multiple Myeloma (34% recruiting · 68 trials)

Prostate Cancer36.7%Depression35.7%Breast Cancer (this)34%Obesity28.9%Healthy20.5%
Open-enrollment share among volume-matched conditions near Breast Cancer

Breast Cancer lists 423 open slots (34% of 1,251 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →

Key findings

What ClinicalTrials.gov does not surface for Breast Cancer on its own pages , computed from the registry mirror as of 2026-08-08. 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 37.1% average across 139 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 5 of 26

RECRUITING NA 131 participants

A Study of a Decision Tool for People Considering Breast Reconstruction Surgery

Memorial Sloan Kettering Cancer Center

NCT07335354

RECRUITING 130 participants

Individuals on Hormone Therapy Breast Cancer Screening Pilot

Medical College of Wisconsin

NCT06383026

RECRUITING Phase 2 130 participants

A Study of Blood Pressure Control During Cancer Treatment

Memorial Sloan Kettering Cancer Center

NCT06023576

RECRUITING NA 130 participants

A Study of Mental Health Care in People With Cancer

Memorial Sloan Kettering Cancer Center

NCT06037954

RECRUITING Phase 3 126 participants

Trial Of PreoperAtive Radiation (TOPAz): A Randomized Trial Comparing Hypofractionated Versus Conventionally Fractionated Preoperative Radiation Followed by Mastectomy With Immediate Autologous Breast Reconstruction With Integrated Nanomechanical Biomarker Evaluation

M.D. Anderson Cancer Center

NCT05774678

RECRUITING Phase 2 125 participants

A Phase 2 Neoadjuvant Study of Zanidatamab in Combination With Chemotherapy in Participants With HER2-positive Breast Cancer

Jazz Pharmaceuticals

NCT07102381

RECRUITING Phase 1 124 participants

Administering Peripheral Blood Lymphocytes Transduced With a CD70-Binding Chimeric Antigen Receptor to People With CD70 Expressing Cancers

National Cancer Institute (NCI)

NCT02830724

RECRUITING Phase 1 122 participants

A Trial of AMXI-5001 for Treatment in Patients With Advanced Malignancies

AtlasMedx, Incorporated

NCT04503265

RECRUITING NA 120 participants

Cryoablation vs Lumpectomy in T1 Breast Cancers

Washington University School of Medicine

NCT05505643

RECRUITING Phase 2 120 participants

Phase II Study of Systemic Screening in Pathologic Node Positive Breast Cancer

H. Lee Moffitt Cancer Center and Research Institute

NCT06833502

RECRUITING Phase 1 120 participants

A Study of PARG Inhibitor ETX-19477 in Patients With Advanced Solid Malignancies

858 Therapeutics

NCT06395519

RECRUITING 120 participants

Generation of Heart Muscle Cells From Blood or Skin Cells of Breast Cancer Patients

Memorial Sloan Kettering Cancer Center

NCT02772367

RECRUITING NA 120 participants

Randomized Feasibility Trial for Mesh in Pre-Pectoral Reconstruction

University of California, Los Angeles

NCT05190978

RECRUITING NA 120 participants

Personalized Second Chance Breast Conservation (PSCBC): A Prospective Phase II Clinical Study

Weill Medical College of Cornell University

NCT04371913

RECRUITING NA 120 participants

Promoting Resilience in Women With Breast Cancer (PRISM -MBC)

UNC Lineberger Comprehensive Cancer Center

NCT06855654

RECRUITING NA 120 participants

Evaluating Digital Micro-Interventions to Reduce Distress and Increase Wellbeing in Breast Cancer Survivors

University of Virginia

NCT07160439

RECRUITING NA 115 participants

A Randomized Controlled Trial (RCT) to Determine the Efficacy of a Multidisciplinary CBT Based Pain Management Program for the Treatment of Aromatase Inhibitor Associated Musculoskeletal Symptoms (AIMSS) in Breast Cancer Survivors

Mayo Clinic

NCT06831838

RECRUITING Phase 1 115 participants

Dose Escalation and Dose Expansion Study of MDX2001 in Patients With Advanced Solid Tumors

ModeX Therapeutics, An OPKO Health Company

NCT06239194

RECRUITING NA 114 participants

Breast Re-irradiation After Second Ipsilateral Lumpectomy

Youssef Zeidan

NCT06867484

RECRUITING Phase 1 113 participants

FT836 With or Without Chemotherapy and/or Monoclonal Antibodies, in Participants With Advanced Solid Tumors

Fate Therapeutics

NCT07216105

RECRUITING Phase 2 110 participants

Sacituzumab Govitecan +/- Pembrolizumab in Metastatic TNBC

Dana-Farber Cancer Institute

NCT04468061

RECRUITING Phase 1 110 participants

A Study to Learn About Study Medicine ALTA2618 in Adults With AKT1 E17K-Mutant Solid Tumors

Alterome Therapeutics

NCT06533059

RECRUITING Phase 2 110 participants

Solifenacin Compared to Clonidine for Reducing Hot Flashes Among Breast Cancer Patients

University of Arkansas

NCT01530373

RECRUITING Phase 2 105 participants

Artificial Intelligence and Machine Learning to Guide CDK4/6 Inhibitor Rechallenge in Breast Cancer.

University of California, San Diego

NCT07227233

RECRUITING Early Phase 1 104 participants

Neuromodulation of Cardiovascular Risks Associated With Cardiotoxic Chemotherapy

University of Oklahoma

NCT05921253

RECRUITING 102 participants

Self Reported Pain in Women While Undergoing Treatment for Non-metastatic Breast Cancer

Wake Forest University Health Sciences

NCT04174742

RECRUITING Phase 2 102 participants

Combined Immunotherapies in Metastatic ER+ Breast Cancer

Weill Medical College of Cornell University

NCT04563507

RECRUITING Phase 1 100 participants

Safety, PK and Efficacy of QXL138AM in Patients With Solid Tumors and Multiple Myeloma

Nammi Therapeutics

NCT06582017

RECRUITING 100 participants

COOL-IT-PRO: Cryoablation of Breast Cancer in Non-surgical Patients

Washington University School of Medicine

NCT05972343

RECRUITING Phase 4 100 participants

Role of TXA in Patients Undergoing Breast Free Flap Reconstruction

University of Virginia

NCT06428682

RECRUITING 100 participants

Circulating Tumor DNA (ctDNA) for Early Treatment Response Assessment of Solid Tumors

Washington University School of Medicine

NCT04354064

RECRUITING Phase 3 100 participants

A Study of Dato-DXd in Inoperable or Metastatic Hormone Receptor-positive, HER2 IHC 0 Breast Cancer

AstraZeneca

NCT07205822

RECRUITING 100 participants

CTNNA1 Familial Expansion Study

Abramson Cancer Center at Penn Medicine

NCT05126290

RECRUITING NA 100 participants

Evaluation of Radiobiological Effects in Skin Toxicities for Breast Cancer Patients With Pencil Beam Scanning Proton Therapy

Covenant Health Cancer Center

NCT06006806

RECRUITING NA 100 participants

The Florida ASCENT Study

University of Florida

NCT07042243

RECRUITING Phase 4 100 participants

Post-mastectomy Recovery: Comparing Preoperative PECS-II Blocks With Intraoperative Pectoral Blocks

University of Cincinnati

NCT06574022

RECRUITING NA 100 participants

Molecular Residual Disease Assessment in a Representative Diverse Population of Patients With Early-stage Breast Cancer

UNC Lineberger Comprehensive Cancer Center

NCT07025785

RECRUITING Phase 1 100 participants

A Study of Disitamab Vedotin in Adults With HER2 Expressing Advanced Breast Cancer

Pfizer

NCT06966453

RECRUITING 100 participants

Observational Study of Bone Complications in People With Post-menopausal Breast Cancer Who Have Stopped Treatment With Denosumab and Aromatase Inhibitors

Memorial Sloan Kettering Cancer Center

NCT05590949

RECRUITING Phase 2 100 participants

Molecular Analyses to Predict Pathways of Endocrine Resistance Following Short Term Neoadjuvant Endocrine Treatment in Patients With Hormone Receptor-Positive HER2-negative Breast Cancer

Medical College of Wisconsin

NCT06361940

RECRUITING NA 100 participants

Exercise in Metastatic Breast Cancer: EMBody

Indiana University

NCT05468034

RECRUITING Phase 2 100 participants

Converting HR+ Breast Cancer Into an Individualized Vaccine

Weill Medical College of Cornell University

NCT03804944

RECRUITING 99 participants

Myeloid-Derived Suppressor Cell Function in Breast Cancer Patients

Ohio State University Comprehensive Cancer Center

NCT04022616

RECRUITING NA 99 participants

Study to Assess the Ability of the Portable Scalp Cooling System (PSCS) to Prevent Hair Loss

Cooler Heads Care

NCT05484973

RECRUITING NA 98 participants

Real-Time Assessment Of Breast Cancer Lumpectomy Specimen Margins With Nonlinear Microscopy

Beth Israel Deaconess Medical Center

NCT02926729

RECRUITING Phase 2 96 participants

Avelumab or Hydroxychloroquine with or Without Palbociclib to Eliminate Dormant Breast Cancer

Abramson Cancer Center at Penn Medicine

NCT04841148

RECRUITING Phase 1 96 participants

Study of the Kinesin Oral Molecular Degrader BBI-940 in Subjects With Advanced or Metastatic Breast Cancer

Boundless Bio

NCT07408089

RECRUITING NA 95 participants

TMEM-MRI: A Pilot Feasibility Study of MRI for Imaging of TMEM in Patients With Operable Breast Cancer

Montefiore Medical Center

NCT03694756

RECRUITING Phase 2 90 participants

A Phase 2 Study of PCS6422 With Capecitabine in Patients With Advanced or Metastatic Breast Cancer

Processa Pharmaceuticals

NCT06568692

RECRUITING Phase 1 90 participants

A Study of CLSP-1025 in Adult Patients With Solid Tumors That Harbor the p53 R175H Mutation

Clasp Therapeutics

NCT06778863

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Phase Distribution

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

Named interventions

Most-linked intervention names on Breast Cancer records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.

Fulvestrant Drug
33 trials
Paclitaxel Drug
32 trials
Trastuzumab Drug
26 trials
Letrozole Drug
24 trials
Pembrolizumab Drug
23 trials
Cyclophosphamide Drug
21 trials
Capecitabine Drug
20 trials
Abemaciclib Drug
19 trials

US sites by state

Facility locations filed on Breast Cancer trials. A trial with sites in several states counts in each.

California 298 trials
New York 270 trials
Texas 210 trials
Florida 206 trials
Massachusetts 184 trials
North Carolina 126 trials
Illinois 123 trials
Pennsylvania 122 trials

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

What to do with this Breast Cancer page

1,251 registered trials, 423 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Breast Cancer condition card totals 1,251 registered trials; most-linked intervention Fulvestrant; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.