A phase II study of atezolizumab, pertuzumab, and high-dose trastuzumab for central nervous system metastases in patients with HER2-positive breast cancer

Patients with HER2-positive breast cancer brain metastases have few effective systemic therapy options. In a prior study, pertuzumab with high-dose trastuzumab demonstrated a high clinical benefit rate (CBR) in the central nervous system (CNS) in patients with brain metastases. The current trial evaluated whether the addition of atezolizumab to this regimen would produce further improvements in CNS response.