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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 13 of 26

ACTIVE NOT RECRUITING NA 80 participants

Omega 3 Fatty Acids and ERPR(-)HER2(+/-) Breast Cancer Prevention

City of Hope Medical Center

NCT02295059

ACTIVE NOT RECRUITING Phase 1 78 participants

ZAP-IT: ZN-c3 + Carboplatin + Pembrolizumab in mTNBC

Filipa Lynce, MD

NCT06351332

ACTIVE NOT RECRUITING Phase 1 78 participants

A Study of DS-1103a Combination Therapy in Participants With Advanced Solid Tumors

Daiichi Sankyo

NCT05765851

ACTIVE NOT RECRUITING 78 participants

Use of Sentinel Lymph Node Biopsy in Patients With Early-Stage, Palpable Node-Positive HR+/HER2- Breast Cancer Having Upfront Surgery and Adjuvant Radiation

Memorial Sloan Kettering Cancer Center

NCT04854005

ACTIVE NOT RECRUITING Phase 2 78 participants

Carboplatin +/- Nivolumab in Metastatic Triple Negative Breast Cancer

Dana-Farber Cancer Institute

NCT03414684

ACTIVE NOT RECRUITING Phase 1 77 participants

AKT Inhibitor, Ipatasertib, With Endocrine and CDK 4/6 Inhibitor for Patients With Metastatic Breast Cancer (TAKTIC)

Massachusetts General Hospital

NCT03959891

ACTIVE NOT RECRUITING NA 77 participants

Three Fraction Accelerated Partial Breast Irradiation as the Sole Method of Radiation Therapy for Low-risk Stage 0 and I Breast Carcinoma

Washington University School of Medicine

NCT03612648

ACTIVE NOT RECRUITING Phase 1 75 participants

Study to Evaluate Sacituzumab Govitecan in Combination With Talazoparib in Patients With Metastatic Breast Cancer.

Massachusetts General Hospital

NCT04039230

ACTIVE NOT RECRUITING NA 74 participants

Phase II Multi-center Trial Evaluating 5 Fraction Stereotactic Partial Breast Irradiation Using Gammapod

University of Texas Southwestern Medical Center

NCT03581136

ACTIVE NOT RECRUITING Phase 1 71 participants

A Study to Learn About Vepdegestrant When Given With PF-07220060 to People With Advanced or Metastatic Breast Cancer.

Pfizer

NCT06206837

ACTIVE NOT RECRUITING Phase 1 71 participants

Study of NGM438 as Monotherapy and in Combination With Pembrolizumab in Advanced or Metastatic Solid Tumors

NGM Biopharmaceuticals

NCT05311618

ACTIVE NOT RECRUITING Phase 2 70 participants

Phase II Study of Pembrolizumab and Nab-paclitaxel in HER-2 Negative Metastatic Breast Cancer

NYU Langone Health

NCT02752685

ACTIVE NOT RECRUITING NA 70 participants

Searching for Masses and Calcifications at the Same Time in Breast Cancer Screening

Brigham and Women's Hospital

NCT05975736

ACTIVE NOT RECRUITING Phase 2 68 participants

Carboplatin and Nab-Paclitaxel With or Without Vorinostat in Treating Women With Newly Diagnosed Operable Breast Cancer

Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins

NCT00616967

ACTIVE NOT RECRUITING 68 participants

Study of the Safety of MRI Scans in People Who Have Breast Tissue Expanders After Mastectomy

Memorial Sloan Kettering Cancer Center

NCT04769960

ACTIVE NOT RECRUITING NA 68 participants

Moving Forward Together 4

University of South Carolina

NCT05409664

ACTIVE NOT RECRUITING Phase 1 66 participants

Breast Cancer Study of Preoperative Pembrolizumab + Radiation

Stephen Shiao

NCT03366844

ACTIVE NOT RECRUITING Phase 2 62 participants

Niraparib + Dostarlimab In BRCA Mutated Breast Cancer

Dana-Farber Cancer Institute

NCT04584255

ACTIVE NOT RECRUITING Phase 2 61 participants

Preoperative Fulvestrant With or Without Enzalutamide in ER+/Her2- Breast Cancer

University of Colorado, Denver

NCT02955394

ACTIVE NOT RECRUITING NA 60 participants

Rehabilitation of Cognitive Changes in Breast Cancer Survivors

Memorial Sloan Kettering Cancer Center

NCT01182506

ACTIVE NOT RECRUITING 60 participants

Prospective Study of the Prosigna Assay on Neoadjuvant Clinical Decision-making in Women With HR+/Her2- Breast Cancer

Dana-Farber Cancer Institute

NCT03749421

ACTIVE NOT RECRUITING NA 60 participants

Physical Activity, Proliferation and Immune Markers in Benign Breast Tissue

Dana-Farber Cancer Institute

NCT03657628

ACTIVE NOT RECRUITING NA 60 participants

Psychosexual Educational Partners Program (PEPP)

The University of Tennessee, Knoxville

NCT06253182

ACTIVE NOT RECRUITING NA 60 participants

Ultrahypofractionation and Normal Tissue Toxicity

Massachusetts General Hospital

NCT05912231

ACTIVE NOT RECRUITING Phase 3 59 participants

Vepdegestrant (ARV-471/PF-07850327) + Palbociclib vs Letrozole + Palbociclib in ER(+)/HER2(-) Advanced Breast Cancer

Pfizer

NCT05909397

ACTIVE NOT RECRUITING NA 56 participants

Hypofractionated Regional Nodal Irradiation in Breast Cancer

Corewell Health East

NCT06443359

ACTIVE NOT RECRUITING NA 53 participants

Part II: Exercise in Hispanic Breast Cancer Survivors

M.D. Anderson Cancer Center

NCT01504789

ACTIVE NOT RECRUITING Phase 1 51 participants

Cisplatin Plus Romidepsin & Nivolumab in Locally Recurrent or Metastatic Triple Negative Breast Cancer (TNBC)

Priyanka Sharma

NCT02393794

ACTIVE NOT RECRUITING Phase 2 51 participants

Clinical Trial Assessing the Safety of Neoadjuvant Palbociclib in Combination With Endocrine Therapy

University of Nebraska

NCT05069038

ACTIVE NOT RECRUITING 50 participants

Imaging of Primary or Recurrent Breast Cancer With 18F-FluorThanatrace PET/CT

University of Pennsylvania

NCT03846167

ACTIVE NOT RECRUITING NA 50 participants

Heart Health After Cancer Treatment (HEART-ACT)

University of California, San Francisco

NCT06055803

ACTIVE NOT RECRUITING Phase 1 50 participants

Onvansertib + Paclitaxel In TNBC

Antonio Giordano, MD

NCT05383196

ACTIVE NOT RECRUITING Phase 2 50 participants

Feasibility Study of Adjuvant Enzalutamide for the Treatment of Early Stage AR (+) Triple Negative Breast Cancer

Memorial Sloan Kettering Cancer Center

NCT02750358

ACTIVE NOT RECRUITING Phase 2 50 participants

Study of Neoadjuvant Olaparib Monotherapy and Olaparib and Durvalumab Combination in HER2 Negative BRCAm Breast Cancer

AstraZeneca

NCT05498155

ACTIVE NOT RECRUITING NA 49 participants

The Preoperative Health & Body Study

Dana-Farber Cancer Institute

NCT01516190

ACTIVE NOT RECRUITING 49 participants

Brain Functional MRI in Older Women With Breast Cancer (Brain fMRI-BC)

City of Hope Medical Center

NCT01992432

ACTIVE NOT RECRUITING 49 participants

Longitudinal ctDNA Surveillance for Older Women With ER+ Breast Cancer Who Omit Surgery

University of Pittsburgh

NCT05914792

ACTIVE NOT RECRUITING Phase 1 48 participants

CAR-macrophages for the Treatment of HER2 Overexpressing Solid Tumors

Carisma Therapeutics

NCT04660929

ACTIVE NOT RECRUITING Phase 2 47 participants

Study of Pembrolizumab Plus Fulvestrant in Hormone Receptor Positive, HER-2 Negative Advanced/Metastatic Breast Cancer Patients

Nancy Chan, MD

NCT03393845

ACTIVE NOT RECRUITING NA 45 participants

A Study of the Use of Text Message Reminders to Take Palbociclib

Memorial Sloan Kettering Cancer Center

NCT04216576

ACTIVE NOT RECRUITING Phase 2 45 participants

Determinants of Resistance to Endocrine Therapy and a Cyclin-dependent Kinases 4 and 6 (CDK4/6) Inhibitor for HR+ MBC

Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins

NCT03439735

ACTIVE NOT RECRUITING Phase 1 45 participants

A Phase I Dose Escalation Study of Single Fraction Pre-operative Partial Breast (S-PBI) for Early Stage Breast Cancer

University of Texas Southwestern Medical Center

NCT04040569

ACTIVE NOT RECRUITING Phase 1 44 participants

CFI-402257, a Potent and Selective TTK Inhibitor, in Solid Tumors and With Fulvestrant in Breast Cancer

Treadwell Therapeutics

NCT05251714

ACTIVE NOT RECRUITING Phase 2 43 participants

A Study of Flibanserin in Breast Cancer Survivors on Tamoxifen or Aromatase Inhibitors

Memorial Sloan Kettering Cancer Center

NCT03707340

ACTIVE NOT RECRUITING 43 participants

Assessment of Paclitaxel-Induced Neuropathy

University of Chicago

NCT01953159

ACTIVE NOT RECRUITING NA 43 participants

Feasibility and Identification of Breast Cancer Patients for Potential Avoidance of Surgery

M.D. Anderson Cancer Center

NCT02455791

ACTIVE NOT RECRUITING Phase 2 43 participants

A Study of the Body's Response to Exercise and a Plant-Based Diet in Overweight Postmenopausal Women With Breast Cancer

Memorial Sloan Kettering Cancer Center

NCT04298086

ACTIVE NOT RECRUITING 42 participants

Exercise, Fitness and Tumor Profiling in Breast Cancer Patients

Memorial Sloan Kettering Cancer Center

NCT03424915

ACTIVE NOT RECRUITING NA 42 participants

Curcumin in Reducing Joint Pain in Breast Cancer Survivors With Aromatase Inhibitor-Induced Joint Disease

City of Hope Medical Center

NCT03865992

ACTIVE NOT RECRUITING Phase 1 41 participants

'ADVANCE' (A Pilot Trial)

Dana-Farber Cancer Institute

NCT03858322

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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.