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Active, not recruiting Phase 3 Interventional

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)

ClinicalTrials.gov ID: NCT03725059

Public ClinicalTrials.gov record NCT03725059. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 13, 2026, 12:33 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

A Randomized, Double-Blind, Phase III Study of Pembrolizumab Versus Placebo in Combination With Neoadjuvant Chemotherapy and Adjuvant Endocrine Therapy for the Treatment of High-Risk Early-Stage Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative (ER+/HER2-) Breast Cancer (KEYNOTE-756)

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

The purpose of this study is to assess the efficacy and safety of pembrolizumab (MK-3475) versus placebo in combination with neoadjuvant (pre-surgery) chemotherapy and adjuvant (post-surgery) endocrine therapy in the treatment of adults who have high-risk early-stage estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. The primary study hypotheses are: 1) pembrolizumab is superior to placebo, both in combination with the protocol-specified neoadjuvant anticancer therapy, as assessed by pathological Complete Response (pCR) rate defined by the local pathologist, and 2) pembrolizumab is superior to placebo (both in combination with the protocol-specified neoadjuvant and adjuvant anticancer therapies) as assessed by Event-Free Survival (EFS) as determined by the investigator. The study is considered to have met its primary objective if pembrolizumab is superior to placebo with respect to either pCR (ypT0/Tis ypN0) or EFS.

Study identification

NCT ID
NCT03725059
Recruitment status
Active, not recruiting
Study type
Interventional
Phase
Phase 3
Lead sponsor
Merck Sharp & Dohme LLC
Industry
Enrollment
1,240 participants

Conditions and interventions

Conditions

Interventions

Biological · Drug · Radiation + 1 more

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Dec 26, 2018
Primary completion
Jan 23, 2031
Completion
Jan 23, 2031
Last update posted
Jul 10, 2025

2018 – 2031

United States locations

U.S. sites
45
U.S. states
26
U.S. cities
42
Facility City State ZIP Site status
Southern Cancer Center, PC ( Site 8003) Daphne Alabama 36526
Cancer Treatment Centers of America at Western Regional Medical Center ( Site 0001) Goodyear Arizona 85338
Arizona Oncology Associates PC- HOPE ( Site 8008) Tucson Arizona 85704
Cedars Sinai Medical Center Samuel Oschin Comp. Cancer Institute ( Site 0079) Los Angeles California 90048
El Camino Hospital Cancer Center ( Site 0004) Mountain View California 94040
Stanford Cancer Center ( Site 0072) Palo Alto California 94304
UC Davis Comprehensive Cancer Center ( Site 0073) Sacramento California 95817
University of Colorado, Anschutz Cancer Pavilion ( Site 0008) Aurora Colorado 80045
Baptist MD Anderson Cancer Center ( Site 0014) Jacksonville Florida 32207
Southeastern Regional Medical Center, Inc. ( Site 0075) Newnan Georgia 30265
The University of Chicago Medical Center ( Site 0080) Chicago Illinois 60637
Orchard Healthcare Research Inc. ( Site 0020) Skokie Illinois 60077
Midwestern Regional Medical Center, Inc. ( Site 0077) Zion Illinois 60099
Goshen Center for Cancer Care ( Site 0021) Goshen Indiana 46526
MercyOne Waterloo Cancer Center ( Site 0016) Waterloo Iowa 50702
James Graham Brown Cancer Center ( Site 0022) Louisville Kentucky 40202
Maryland Oncology Hematology, P.A. ( Site 8007) Bethesda Maryland 20817
Massachusetts General Hospital ( Site 0024) Boston Massachusetts 02114
MGH - North Shore Cancer Center ( Site 0081) Danvers Massachusetts 01923
MGH Newton-Wellesley Hospital's Vernon Cancer Center ( Site 0082) Newton Massachusetts 02462
Henry Ford Health System ( Site 0028) Detroit Michigan 48202
Mayo Clinic and Medical School (Rochester) ( Site 0029) Rochester Minnesota 55905
St. Vincent Frontier Cancer Center ( Site 0033) Billings Montana 59102
Oncology Hematology West, PC dba Nebraska Cancer Specialists ( Site 0039) Omaha Nebraska 68130
Holy Name Medical Center ( Site 0041) Teaneck New Jersey 07666
Weill Cornell Medical College ( Site 0043) New York New York 10065
CTCA Southwestern ( Site 0074) Tulsa Oklahoma 74133
OHSU Knight Cancer Institute ( Site 0051) Portland Oregon 97239
Northwest Cancer Specialists, P.C. ( Site 8000) Tigard Oregon 97223
Geisinger Medical Center ( Site 0052) Danville Pennsylvania 17822
Fox Chase Cancer Center ( Site 0078) Philadelphia Pennsylvania 19111
Cancer Treatment Centers of America-Eastern Regional Medical Center ( Site 0076) Philadelphia Pennsylvania 19124
Medical University of South Carolina ( Site 0053) Charleston South Carolina 29425
Tennessee Oncology, PLLC/The Sarah Cannon Research Institute ( Site 7000) Nashville Tennessee 37203
Texas Oncology-Austin Central ( Site 8004) Austin Texas 78731
Texas Oncology-Dallas Presbyterian Hospital ( Site 8002) Dallas Texas 75231
Texas Oncology-Baylor Charles A. Sammons Cancer Center ( Site 8009) Dallas Texas 75246
Texas Oncology-Memorial City ( Site 8012) Houston Texas 77024
University of Texas-MD Anderson Cancer Center ( Site 0083) Houston Texas 77030
Texas Oncology- Plano East ( Site 8010) Plano Texas 75075
Texas Oncology - Northeast Texas ( Site 8006) Tyler Texas 75702
Bon Secours St. Francis Medical Center Oncology Research ( Site 0064) Midlothian Virginia 23114
Virginia Oncology Associates ( Site 8001) Norfolk Virginia 23502
Kadlec Clinic Hematology and Oncology ( Site 0070) Kennewick Washington 99336
Medical Oncology Associates (Summit Cancer Centers) ( Site 0066) Spokane Washington 99208

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 199 non-U.S. sites.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT03725059, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jul 10, 2025 · Synced Sep 13, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT03725059 live on ClinicalTrials.gov.

View official ClinicalTrials.gov record →