# 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)

> **NCT03725059** · PHASE3 · ACTIVE_NOT_RECRUITING · sponsor: **Merck Sharp & Dohme LLC** · enrollment: 1240 (estimated)

## Conditions studied

- Breast Cancer

## Interventions

- **BIOLOGICAL:** Pembrolizumab (K)
- **DRUG:** Placebo (P)
- **DRUG:** Paclitaxel (X)
- **DRUG:** Doxorubicin (A)
- **DRUG:** Epirubicin (E)
- **DRUG:** Cyclophosphamide (C)
- **DRUG:** Endocrine therapy
- **RADIATION:** Radiation therapy
- **PROCEDURE:** Surgery

## Key facts

- **NCT ID:** NCT03725059
- **Lead sponsor:** Merck Sharp & Dohme LLC
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE3
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2018-12-27
- **Primary completion:** 2031-01-24
- **Final completion:** 2031-01-24
- **Target enrollment:** 1240 (ESTIMATED)
- **Last updated:** 2025-07-11


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT03725059

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT03725059, "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)". Retrieved via AI Analytics 2026-06-05 from https://api.ai-analytics.org/clinical/NCT03725059. Licensed CC0.

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