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Pembrolizumab and Stereotactic Radio Surgery (SRS) of Selected Brain Metastases in Breast Cancer Patients

Clinical Trial Details

Breast cancer subjects with multiple brain metastases are often initially treated with stereotactic radiosurgery (SRS), a non-surgical radiation technique used to treat small brain tumors or whole brain radiation therapy (WBRT). When initially managed with SRS, subjects often develop new brain metastases in the untreated brain, requiring additional SRS procedures and, eventually, WBRT, which is often associated with significant neurocognitive sequelae (headache, nausea, dizziness, confusion, memory loss and motor dysfunction). Strategies to decrease the rate of new brain metastases are warranted.

This study will test whether combining SRS with a study immunotherapy drug can elicit an immune response against the irradiated tumor lesion and tumor lesion distal to the irradiated site. The immunotherapy tested in this trial is Pembrolizumab (Keytruda), which blocks a protective mechanism of cancer cells and allows the immune system to destroy those cancer cells. 

In summary, we are proposing to test whether SRS to a select number of brain metastases in combination with Pembrolizumab can effectively induce an immune response in the brain and rest of the body leading to tumor regression 

Key Eligibility: 

Inclusion Criteria 

  • Age older than 18
  • Eastern Cooperative Oncology Group (ECOG) performance status 0-1
  • Men and/or pre- or post-menopausal women with metastatic breast cancer with at least 2 intracranial untreated and measurable (≥ 5mm) metastases as visualized on brain MRI 
  • A diagnostic contrast enhanced MRI demonstrating at least 2 and no more than 10 measurable lesions in the brain, (≥5mm in size), performed within two weeks prior to treatment 

Exclusion Criteria 

  • Active connective tissue disorders, such as lupus or scleroderma requiring flare therapy |
  • Current use of systemic chemotherapy 
  • Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (eg, CTLA-4, OX 40, CD137)
  • Patients who have undergone complete resection of all known brain metastases 

Study contact by location

Upper East Side - Manhattan


Maria Fenton-Kerimian
(212) 746-6074

Primary Investigator(s)

Protocol ID(s)

Weill Cornell Medicine IRB #:




Open to Enrollment

Age Group