Testing MK-3475 (Pembrolizumab) as Adjuvant Therapy for Triple Receptor-Negative Breast Cancer


If you have "triple negative" breast cancer you may qualify for this study. 

This means that your type of breast cancer doesn’t have receptors for estrogen, progesterone, or the protein HER2, that are found in some other types of breast cancer. Additionally, you have already had preoperative chemotherapy (also called “neoadjuvant” chemotherapy) and your breast cancer has at least partly survived
that treatment

The purpose of this study is to compare the usual approach (i.e. no more treatment or additional post-operative chemotherapy), to any effects, good and/or bad, of the experimental drug MK-3475 (also called pembrolizumab) after surgery. This study will allow the researchers to know whether treatment with MK-3475 (pembrolizumab) is better, the same, or worse than the usual approach.


This study has two study groups (also called study “arms”). A computer will by chance assign you to one of the two study arms.

Arm 1

If you are in Arm 1, you will get observation with close clinical monitoring. Your doctors may recommend postoperative radiotherapy, or more post-operative chemotherapy, as part of your usual treatment.

This treatment plan must be determined by you and your physician before entering the trial. If you are assigned to Arm 1, you may not receive any other treatment that is not part of the study. You will have visits with your physician every 12 weeks for one year. 

Arm 2

If you are in Arm 2, you will receive MK-3475 (pembrolizumab) by intravenous infusion over a 30-minute period. You will not have to be hospitalized for this infusion unless your doctor feels it is needed.

You will receive MK-3475 (pembrolizumab) infusions every three weeks for one year and will be seen by your physician every six weeks during treatment. Your doctors may also recommend postoperative radiotherapy.

For questions about study procedures and details about each study arm, please contact Karen Daily:


  • Patients must have histologically confirmed estrogen receptor (ER)-, progesterone receptor (PR)- and HER2-negative (triple-negative, TNBC) or ER, PR, and HER2 equivocal status and must not have received and not be planning to receive adjuvant anti-HER2 or endocrine therapies after completion of neoadjuvant chemotherapy
  • Patients who are HER2 positive by American Society of Clinical Oncology (ASCO) College of American Pathologists (CAP) guidelines are ineligible
  • HER2 negative and HER2 equivocal cases as per ASCO CAP guidelines that do not receive HER2-targeted therapy are eligible
  • Patients with weekly ER or PR positive disease, defined as ER and/or PR < 5% by immunohistochemistry, are eligible if the treating physician considers the patient not eligible for adjuvant endocrine therapy
  • Residual disease must be >= 1 cm in greatest dimension, and/or have positive lymph nodes (ypN+) observed on pathologic exam
  • NOTE: Immunohistochemistry (IHC)-positive isolated tumor cells in the lymph node (N0 [i+]) are not considered node-positive and these patients also must have >= 1 cm Residual invasive cancer in the breast in order to be eligible
  • Patients must not have metastatic disease (i.e., must be M0); patients must not have locally recurrent disease
  • It is preferred that axillary lymph node sampling is performed after completion of neoadjuvant chemotherapy to allow more accurate assessment of pathologic response
  • Patients must have a complete axillary lymph node dissection after neoadjuvant chemotherapy in the following situations (exceptions will be granted for patients participating in the Alliance A11202 trial):
  • Patients had documented pathologic involvement of the axillary nodes (fine needle aspiration [FNA] or core biopsy) before neoadjuvant chemotherapy and had sentinel node biopsy after neoadjuvant chemotherapy with positive sentinel node(s)
  • Patient had documented pathologic involvement of the axillary nodes (FNA or core biopsy) before neoadjuvant chemotherapy and had only 1 sentinel lymph node removed after neoadjuvant chemotherapy
  • NOTE: Patients who undergo sentinel node biopsy before starting neoadjuvant treatment and do not undergo post neoadjuvant assessment of the axillary nodes or who have negative axillary nodes on post neoadjuvant assessment must have >= 1 cm residual invasive cancer in the breast after completion of neoadjuvant chemotherapy


18 to 65
65 and over



Monetary compensation


Can be done from home



Breast cancer

Principal Investigator

Karen Daily, D.O.


Hematology and Oncology

Contact Information



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