Testing MK-3475 (pembrolizumab) as adjuvant therapy for triple receptor-negative breast cancer (S1418)


This randomized phase III trial studies how well pembrolizumab works in treating patients with triple-negative breast cancer. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread.


Accepting new patients

Primary Study Objective(s)

The primary objective of this study is to compare invasive disease-free survival (IDFS) of patients with triple-negative (TNBC) or low estrogen receptor (ER)-positive and/or HER2 borderline breast cancer who have >= 1 cm residual invasive breast cancer and/or positive lymph nodes (ypN1mi, ypN1, ypN2, ypN3) after neoadjuvant chemotherapy randomized to receive one year of MK-3475 (pembrolizumab) adjuvant therapy compared to no MK-3475 (pembrolizumab), in both the entire study population and also in the PD-L1 positive subset.

Core eligibility

Note: This is only a partial list of eligibility criteria.

Including patients who meet the following criteria:

  • Patients must complete Step 1 registration.
  • Patients must have histologically confirmed estrogen receptor (ER)-, progesterone receptor (PR)- and HER2-negative (triple-negative, TNBC) or ER-, PR- weakly positive and/or 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 weakly ER or PR positive disease, defined as ER and/or PR less than or equal to (=<) 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 (ypN1mi, ypN1, ypN2, ypN3) observed on pathologic exam.
    • NOTE: If the ER and/or HER2 results are discordant between the initial, pre-chemotherapy, and post-chemotherapy surgical tissue, the receptor status of the residual disease has to be used to determine eligibility. 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 to be eligible.
  • Patients must not have metastatic dise¬ase (i.e., must be clinically M0 or Mx; systemic staging studies with imaging should follow routine practice as per National Comprehensive Cancer Network [NCCN] and ASCO guidelines); patients must not have locally recurrent disease.

Accepting new patients


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