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)

Principal Investigator

Apurva Pandey

Study Purpose

This trial is being done to:
• Test the safety and tolerability of the pembrolizumab plus chemotherapy

• See how long participants’ cancer does not get worse while taking the pembrolizumab plus chemotherapy compared to the placebo plus chemotherapy

• See if participants who get pembrolizumab plus chemotherapy live longer compared to those who get the placebo plus chemotherapy

• See if participants have a better quality of life

Medical Condition(s)

chemotherapy-candidate hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) locally recurrent inoperable or metastatic breast cancer

Eligibility Criteria

All adults 18 years and older

Has locally recurrent inoperable or metastatic HR+/HER2- breast cancer

Is a chemotherapy candidate that meets the criteria specified in the protocol

Age Range

18 - 101

Healthy Volunteers Needed


Duration of Participation

You will receive the study drugs for up to three years as long as your cancer does not get worse or you do not have bad side effects. After you are done getting treated with the study drugs, we may contact you every 12 weeks until the study closes to see how you are doing and to ask about your cancer.

Minors Included



Knight Cancer Institute Clinical Trials
503 494-1080


Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Recruitment End


Compensation Provided


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