# Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy for HR+/HER2- Locally Recurrent Inoperable or Metastatic Breast Cancer (MK-3475-B49/KEYNOTE-B49)

Source: https://onco.cc/trials/nct04895358/  
OnCo record `nct04895358` (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 and Capecitabine in advanced solid tumours, run by Merck Sharp & Dohme LLC, active and no longer recruiting.

## Summary

Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy for HR+/HER2- Locally Recurrent Inoperable or Metastatic Breast Cancer (MK-3475-B49/KEYNOTE-B49) is a phase 3 interventional study registered as NCT04895358 by Merck Sharp & Dohme LLC, with 342 participants enrolled, started 2021-06-18 and due to reach its primary completion in 2026-04-24. Interventions recorded: pembrolizumab, paclitaxel, nab-paclitaxel, liposomal doxorubicin, capecitabine and normal saline.

## Fields

- Kind: Trial
- Status: active
- Last checked: 2026-09-16
- Tags: pipeline; ctgov-ingest
- Registry id: NCT04895358
- Phase: 3
- Setting: A Randomized, Double-blind, Placebo-controlled, Phase 3 Study of Pembrolizumab Plus Chemotherapy Versus Placebo Plus Chemotherapy for the Treatment of Chemotherapy-Candidate Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative (HR+/HER2-) Locally Recurrent Inoperable or Metastatic Breast Cancer (KEYNOTE-B49)
- Sponsor: Merck Sharp & Dohme LLC
- Enrolled: 342

## Sources

- ClinicalTrials.gov NCT04895358: https://clinicaltrials.gov/study/NCT04895358

## Connected records

- cancers: [Metastatic cancer (cancer that has spread)](https://onco.cc/cancers/metastatic-cancer/)
- drugs: [Capecitabine](https://onco.cc/drugs/capecitabine/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- companies: [Merck & Co. (MSD)](https://onco.cc/companies/merck/)

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