Breast Cancer - A012103

This phase III trial compares the effect of pembrolizumab to observation for the treatment of patients with early-stage triple-negative breast cancer who achieved a pathologic complete response (pCR) after preoperative chemotherapy in combination with pembrolizumab. 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. This trial may help researchers determine if observation will result in the same risk of cancer coming back as pembrolizumab after surgery in triple-negative breast cancer patients who achieve pathologic complete response after preoperative chemotherapy with pembrolizumab.


  1. Patients must have received neoadjuvant chemotherapy in combination with pembrolizumab for a minimum of 6 cycles. All systemic chemotherapy and ICI therapy should have been completed preoperatively
  2. Diagnosis of early stage, triple negative breast cancer
  3. No residual invasive disease in the breast or lymph nodes after the completion of neoadjuvant therapy
  4. Not pregnant and not nursing


  1. No stage IV (metastatic) breast cancer
  2. No history of any prior (ipsi-or contralateral) invasive breast cancer. Prior DCIS is allowed.
  3. No evidence of recurrent disease following preoperative therapy and surgery
  4. No known active liver disease
  5. Patients with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the New York Heart Association Functional Classification; to be eligible for this trial, patients should be class 2B or better
  6. HIV-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months prior to registration are eligible for this trial
  7. No history of intolerance to pembrolizumab, murine proteins, or any components of the product
  8. No medical conditions that require chronic systemic steroids (>10 mg prednisone daily or equivalent) or any other form of immunosuppressive medications and has required such therapy in the last two years. Replacement therapy (e.g. thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic therapy

Locations: Hartford Hospital, Hartford HealthCare Medical Group - Manchester, Hartford HealthCare Cancer Institute - Avon, Hartford HealthCare Cancer Institute at The Hospital of Central Connecticut, Saint Vincent's Medical Center, MidState Medical Center

Contacts: Hartford region: 860-972-5371; Central region: 860-696-4958

Sponsor: The Alliance for Clinical Trials in Oncology

Cancer Clinical Research Office