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)

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

EU CTIS

Registry ID

CTIS2023-506921-12-00

Acronym

MK-3475-756

Enrollment

424

Registered

2023-11-10

Start date

2018-12-27

Completion date

Unknown

Last updated

2026-01-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

ER+/HER2- Breast Cancer

Brief summary

Pathological Complete Response (pCR) Rate Using the Definition of ypT0/Tis ypN0, Event-Free Survival (EFS)

Detailed description

Overall Survival (OS), pCR Rate Using the Definition of ypT0ypN0, pCR Rate Using the Definition of ypT0/Tis, pCR Rate Using the Definitions of ypT0/Tis ypN0, ypT0/Tis, and ypT0 ypN0 in Participants With a Combined Positive Score [CPS] ≥1, EFS in Participants with a CPS ≥1, OS in Participants with a CPS ≥1, Number of Participants Experiencing an Adverse Event (AE), Number of Participants Experiencing a Serious Adverse Event (SAE), Number of Participants Experiencing an Immune-related AE (irAE), Number of Study Treatment Discontinuations Due to AEs, Change from Baseline in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life (QoL) Questionnaire Core 30 (QLQ-C30) Score, Change from Baseline in EORTC Breast Cancer-Specific QoL Questionnaire (QLQ-BR23) Score

Interventions

DRUGEPIRUBICIN

DRUGKEYTRUDA 25 mg/mL concentrate for solution for infusion

DRUGCYCLOPHOSPHAMIDE

DRUGDOXORUBICIN

DRUGPACLITAXEL

DRUGPacebo to Keytruda: Normal saline or dextrose

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Design outcomes

Primary

Measure	Time frame
Pathological Complete Response (pCR) Rate Using the Definition of ypT0/Tis ypN0, Event-Free Survival (EFS)	—

Secondary

Measure	Time frame
Overall Survival (OS), pCR Rate Using the Definition of ypT0ypN0, pCR Rate Using the Definition of ypT0/Tis, pCR Rate Using the Definitions of ypT0/Tis ypN0, ypT0/Tis, and ypT0 ypN0 in Participants With a Combined Positive Score [CPS] ≥1, EFS in Participants with a CPS ≥1, OS in Participants with a CPS ≥1, Number of Participants Experiencing an Adverse Event (AE), Number of Participants Experiencing a Serious Adverse Event (SAE), Number of Participants Experiencing an Immune-related AE (irAE), Number of Study Treatment Discontinuations Due to AEs, Change from Baseline in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life (QoL) Questionnaire Core 30 (QLQ-C30) Score, Change from Baseline in EORTC Breast Cancer-Specific QoL Questionnaire (QLQ-BR23) Score	—

Measure

Time frame

—

Countries

Belgium, France, Germany, Hungary, Ireland, Poland, Portugal, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026