Targeting Immune Pathways in Breast Cancer

Novel treatment strategies in immunotherapy are benefiting breast cancer patients. Atezolizumab, a PD-L1 inhibitor, has been approved by the FDA, in combination with the chemotherapy drug nab-paclitaxel, for the initial treatment of women with locally advanced or metastatic triple-negative breast cancer that cannot be treated surgically and whose tumors are positive for PD-L1 protein. What biomarkers have been identified? How can they benefit patients?