# 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)

Source: https://onco.cc/trials/nct03725059/  
OnCo record `nct03725059` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A phase 3 trial of Pembrolizumab, Doxorubicin, Epirubicin and Cyclophosphamide in HR-positive / HER2-negative breast cancer, run by Merck Sharp & Dohme LLC, active and no longer recruiting.

## Summary

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) is a phase 3 interventional study registered as NCT03725059 by Merck Sharp & Dohme LLC, with 1240 participants enrolled, started 2018-12-27 and due to reach its primary completion in 2031-01-24. Interventions recorded: Pembrolizumab (K), Placebo (P), Paclitaxel (X), Doxorubicin (A), Epirubicin (E) and Cyclophosphamide (C).

## Fields

- Kind: Trial
- Status: active
- Last checked: 2026-09-16
- Tags: pipeline; ctgov-ingest
- Registry id: NCT03725059
- Phase: 3
- Setting: 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)
- Sponsor: Merck Sharp & Dohme LLC
- Enrolled: 1240

## Sources

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

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- drugs: [Cyclophosphamide](https://onco.cc/drugs/cyclophosphamide/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Epirubicin](https://onco.cc/drugs/epirubicin/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- companies: [Merck & Co. (MSD)](https://onco.cc/companies/merck/)

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