# 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)

> **NCT04895358** · PHASE3 · ACTIVE_NOT_RECRUITING · sponsor: **Merck Sharp & Dohme LLC** · enrollment: 340 (estimated)

## Conditions studied

- Breast Neoplasms

## Interventions

- **BIOLOGICAL:** pembrolizumab
- **DRUG:** paclitaxel
- **DRUG:** nab-paclitaxel
- **DRUG:** liposomal doxorubicin
- **DRUG:** capecitabine
- **DRUG:** normal saline
- **DRUG:** dextrose

## Key facts

- **NCT ID:** NCT04895358
- **Lead sponsor:** Merck Sharp & Dohme LLC
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE3
- **Study type:** INTERVENTIONAL
- **Status:** ACTIVE_NOT_RECRUITING
- **Start date:** 2021-06-18
- **Primary completion:** 2027-12-18
- **Final completion:** 2027-12-18
- **Target enrollment:** 340 (ESTIMATED)
- **Last updated:** 2026-03-11


## Primary source

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

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT04895358, "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)". Retrieved via AI Analytics 2026-06-26 from https://api.ai-analytics.org/clinical/NCT04895358. Licensed CC0.

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