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ClinicalTrials.gov 35 recruiting now early-phase tilt

Breast Neoplasms: early-phase trial registry

35 of 98 indexed Breast Neoplasms trials are currently recruiting, with more weight in Phase 1-2.

Corpus placement: #141 of 28,707 conditions by registered trial count.

98 US clinical trials · 35 currently recruiting · #141 of 28,707 conditions by registered trial count

Breast Neoplasms: 98 US clinical trials tracked, 35 recruiting.

Breast Neoplasms is the subject of 98 registered US clinical trials on ClinicalTrials.gov, 35 of them currently open to new participants. 20 are in Phase 3-4 (later-stage) and 51 in Phase 1-2 (earlier-stage). The most active sponsor is Pfizer, running 10 of these trials.

Enrollment posture brief

Registry condition breast-neoplasms

OPEN 35 | RECR 36% | LATE 20 | EARLY 51 | RANK #141 | SPON 10

Nearest open-share peer: Acute Respiratory Failure (36% recruiting · 14 trials)

Pregnancy Related56%Prostate Adenocarcinoma45%Neuroblastoma38.8%Breast Neoplasms (this)36%Colon Cancer34.3%
Open-enrollment share among volume-matched conditions near Breast Neoplasms

Breast Neoplasms lists 35 open slots (36% of 98 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 Neoplasms 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 Neoplasms is recruiting below its size-band peers.

    35 of 98 indexed trials (35.7%) are open to enrollment, against a 39.7% average across 762 conditions with 20-99 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

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

    Pfizer accounts for 10 of 98 trials (10.2%). 60 distinct sponsors appear on at least one study for this condition label.

  3. Typical Breast Neoplasms enrolment sits around 134 participants.

    Median target enrolment is 134 among the 98 trials that report a genuine target (sentinel values excluded). 40 of those (40.8%) plan for fewer than 100 participants.

  4. Breast Neoplasms research is mostly interventional.

    85 interventional and 13 observational studies make up this index (86.7% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 129Phase 222Phase 319Phase 41

Open and recent trials

98 total, page 2 of 2

ACTIVE NOT RECRUITING Phase 1 134 participants

A Phase 1 Study of ATV-1601 in Patients With Advanced Cancer That Have AKT1 E17K Mutations

Atavistik Bio

NCT07038369

ACTIVE NOT RECRUITING 125 participants

Multi-Institutional Transgender & Gender-Diverse Breast Cancer Study

Medical College of Wisconsin

NCT06234488

ACTIVE NOT RECRUITING Phase 2 84 participants

PD 0332991 and Anastrozole for Stage 2 or 3 Estrogen Receptor Positive and HER2 Negative Breast Cancer

Washington University School of Medicine

NCT01723774

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 Phase 1 44 participants

Anastrozole, Palbociclib, Trastuzumab and Pertuzumab in HR-positive, HER2-positive Metastatic Breast

Icahn School of Medicine at Mount Sinai

NCT03304080

ACTIVE NOT RECRUITING Phase 2 40 participants

Tolerability of the Combination of Lapatinib and Trastuzumab in Adults Age 60 or Older With HER2 Positive Locally Advanced or Metastatic Breast Cancer

City of Hope Medical Center

NCT01273610

ACTIVE NOT RECRUITING Phase 1 34 participants

Trial of Ibrutinib Plus Trastuzumab in HER2-amplified Metastatic Breast Cancer

US Oncology Research

NCT03379428

ACTIVE NOT RECRUITING Phase 1 31 participants

A Study of H3B-6545 in Combination With Palbociclib in Women With Advanced or Metastatic Estrogen Receptor-Positive Human Epidermal Growth Factor Receptor-2 (HER2)-Negative Breast Cancer

Eisai

NCT04288089

ACTIVE NOT RECRUITING Phase 2 12 participants

Pembrolizumab, IRX-2, and Chemotherapy in Triple Negative Breast Cancer

Providence Health & Services

NCT04373031

COMPLETED Phase 3 10,000 participants

Raloxifene Use for The Heart

Eli Lilly and Company

NCT00190593

COMPLETED 1,772 participants

A Study to Understand About the Study Medicine Palbociclib in Breast Cancer Patients After it is Out in the Japanese Market

Pfizer

NCT07096024

COMPLETED Phase 3 865 participants

Phase III Study of Atamestane Plus Toremifene Versus Letrozole in Advanced Breast Cancer

Intarcia Therapeutics

NCT00044291

COMPLETED Phase 3 594 participants

Study Of Sunitinib In Combination With Docetaxel Vs Docetaxel In Patients With Advanced Breast Cancer

Pfizer

NCT00393939

COMPLETED Phase 3 488 participants

A Study Of SU011248 Plus Paclitaxel Versus Bevacizumab Plus Paclitaxel In Patients With Advanced Breast Cancer

Pfizer

NCT00373256

COMPLETED Phase 3 444 participants

A Study Evaluating Trastuzumab Emtansine Plus Pertuzumab Compared With Chemotherapy Plus Trastuzumab and Pertuzumab for Participants With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Breast Cancer

Hoffmann-La Roche

NCT02131064

COMPLETED Phase 3 431 participants

A Study Evaluating Talazoparib (BMN 673), a PARP Inhibitor, in Advanced and/or Metastatic Breast Cancer Patients With BRCA Mutation (EMBRACA Study)

Pfizer

NCT01945775

COMPLETED NA 224 participants

A Study to Determine the Clinical Significance of Molecular Detection of Breast Cancer in the Blood of Stage IV Breast Cancer Patients

Washington University School of Medicine

NCT00355316

COMPLETED NA 191 participants

Hypnosis to Reduce Aromatase Inhibitor Pain and Improve Adherence

Icahn School of Medicine at Mount Sinai

NCT02657993

COMPLETED Phase 1 174 participants

AG-013736 In Combination With Docetaxel Versus Docetaxel Alone For Patients With Metastatic Breast Cancer

Pfizer

NCT00076024

COMPLETED NA 151 participants

Nuevo Amanecer: Promoting the Psychosocial Health of Latinas

University of California, San Francisco

NCT01383174

COMPLETED Phase 1 144 participants

A Study of Multiple Immunotherapy-Based Treatment Combinations in Hormone Receptor (HR)-Positive Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Breast Cancer

Hoffmann-La Roche

NCT03280563

COMPLETED Phase 1 133 participants

This Study in Patients With Different Types of Cancer (Solid Tumours) Aims to Find a Safe Dose of Xentuzumab in Combination With Abemaciclib With or Without Hormonal Therapies. The Study Also Tests How Effective These Medicines Are in Patients With Lung and Breast Cancer

Boehringer Ingelheim

NCT03099174

COMPLETED NA 107 participants

Contrast Enhanced Mammography in Diagnosing Patients With Suspicious Breast Findings

Thomas Jefferson University

NCT03929783

COMPLETED Phase 1 106 participants

A Dose-escalation, Expansion Study of ARX788, in Advanced Solid Tumors Subjects With HER2 Expression (ACE-Pan Tumor 01)

Ambrx

NCT03255070

COMPLETED Early Phase 1 100 participants

Testing of Different Methods for Determining Whether Breast Cancer Has Spread to the Lymph Nodes

Washington University School of Medicine

NCT00360152

COMPLETED NA 100 participants

Efficacy Study of an Educational Program for Decision Support for Breast Cancer

Baylor College of Medicine

NCT00473096

COMPLETED Phase 2 90 participants

Study Of The Efficacy And Safety Of SU-014813 In Patients With Metastatic Breast Cancer

Pfizer

NCT00322517

COMPLETED Phase 1 79 participants

Study of Safety and Efficacy of Alpelisib With Everolimus or Alpelisib With Everolimus and Exemestane in Advanced Breast Cancer Patients, Renal Cell Cancer and Pancreatic Tumors

Novartis Pharmaceuticals

NCT02077933

COMPLETED Phase 2 79 participants

Bevacizumab Given With Either Anastrozole or Fulvestrant With Trastuzumab for Postmenopausal Metastatic Breast Cancer

SCRI Development Innovations

NCT00405938

COMPLETED NA 79 participants

Evaluating and Comparing Two Surgical Methods for Treatment of Early Stage Breast Cancer

Emory University

NCT01271738

COMPLETED Early Phase 1 79 participants

Using Hyperpolarized [1-13C]Pyruvate to Detect Cardiotoxicity

University of Texas Southwestern Medical Center

NCT03685175

COMPLETED 78 participants

Use of Dynamic Contrast-Enhanced Magnetic Resonance Imaging to Assess Tumor-Associated Vasculature in Patients With Metastatic Breast Cancer

National Institute of Neurological Disorders and Stroke (NINDS)

NCT00071357

COMPLETED Phase 3 65 participants

A Prospective, Randomized, Phase III Trial of FLAC (5-Fluorouracil, Leucovorin, Adriamycin, Cytoxan) Chemotherapy With GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor) Versus PIXY 321 in Advanced Breast Cancer

National Cancer Institute (NCI)

NCT00001338

COMPLETED Phase 2 60 participants

Phase 2 Study of TLK286 in Metastatic Breast Cancer

Telik

NCT00035841

COMPLETED Phase 1 58 participants

Vaccination of High Risk Breast Cancer Patients

University of Arkansas

NCT02229084

COMPLETED Phase 2 46 participants

Exemestane and Celecoxib in Postmenopausal Women at High Risk for Breast Cancer

Georgetown University

NCT00073073

COMPLETED Phase 1 42 participants

Study of XL147 (SAR245408) in Combination With Trastuzumab or Paclitaxel and Trastuzumab in Subjects With Metastatic Breast Cancer Who Have Progressed on a Previous Trastuzumab-based Regimen

Sanofi

NCT01042925

COMPLETED Phase 2 41 participants

Enzastaurin For Breast Cancer Patients Who Previously Received an Anthracycline and a Taxane Chemotherapy

Eli Lilly and Company

NCT00386087

COMPLETED NA 40 participants

Know Your Risk: Assessment at Screening for Breast Cancer - Pilot Study

Columbia University

NCT02954900

COMPLETED 33 participants

Treatment Patterns and Clinical Outcomes Among Talazoparib-Treated Adults With HER2-Negative mBC With gBRCA1/2m

Pfizer

NCT05141708

COMPLETED Phase 2 31 participants

PF-3512676 (CPG 7909) Injection For Patients Who Completed An Oncology Study Using PF-3512676 (CPG 7909)

Pfizer

NCT00043368

COMPLETED Phase 2 30 participants

Phase II Study to Evaluate Tariquidar (XR9576), a Selective MDR-1 Inhibitor, in Chemotherapy Resistant Advanced Breast Cancer

QLT

NCT00048633

COMPLETED Phase 2 26 participants

Afatinib (BIBW2992) in HER2 (Human Epidermal Growth Factor Receptor 2)-Overexpressing Inflammatory Breast Cancer

Boehringer Ingelheim

NCT01325428

COMPLETED Phase 1 25 participants

Study of Motexafin Gadolinium and Docetaxel for Advanced Cancer

Pharmacyclics

NCT00120939

COMPLETED 20 participants

Ultrasound Targeting for the Lumpectomy Cavity

University of Iowa

NCT00583843

COMPLETED Phase 1 19 participants

Bright Light on Fatigue in Women Being Treated for Breast Cancer

Washington University School of Medicine

NCT02658708

COMPLETED 13 participants

Studying Normal Breast Tissue and Cancer Risk

National Cancer Institute (NCI)

NCT00341692

COMPLETED Phase 1 9 participants

Evaluating the T Cell Response to a Peptide-based Vaccine in Patients With Breast Cancer

Craig L Slingluff, Jr

NCT00892567

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Phase Distribution

PhaseTrial count
Phase 1 29
Phase 2 22
Phase 3 19
Phase 4 1

Named interventions

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

Anastrozole Drug
7 trials
Fulvestrant Drug
6 trials
Exemestane Drug
6 trials
Paclitaxel Drug
6 trials
Abemaciclib Drug
5 trials
Carboplatin Drug
5 trials
Trastuzumab Drug
5 trials
Capecitabine Drug
4 trials

US sites by state

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

California 42 trials
Florida 27 trials
Texas 26 trials
New York 25 trials
Massachusetts 19 trials
Tennessee 18 trials
Arizona 18 trials
Illinois 16 trials

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

What to do with this Breast Neoplasms page

98 registered trials, 35 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

  • 35 Breast Neoplasms trials are currently recruiting, check eligibility criteria before contacting a site. Browse recruiting trials
  • Pfizer sponsors the most Breast Neoplasms trials on record, review their full trial history before evaluating a specific study. See Pfizer's trials
  • Bring the specific trial ID (NCT number) to your own doctor before enrolling, this page is a directory, not medical guidance. Read the trial-finding guide

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 Neoplasms condition card totals 98 registered trials; most-linked intervention Anastrozole; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.