PD-L1 Protein Expression on Both Tumor Cells and Macrophages are Associated with Response to Neoadjuvant Durvalumab with Chemotherapy in Triple-negative Breast Cancer

PURPOSE: In both the IMpassion 130 trial in the metastatic setting and in Keynote 522 in the neoadjuvant setting, patients with triple-negative breast cancer (TNBC) showed benefit from PD-1 axis immunotherapy. Here, we assess PD-L1 expression on both tumor and immune cells using quantitative immunofluorescence to assess association with benefit from neoadjuvant durvalumab concurrent with chemotherapy in TNBC. EXPERIMENTAL DESIGN: cells, and overall stroma. RESULTS: cells in the tumor or stromal compartments between cases with pCR and non-pCR. CONCLUSIONS: cells is associated with higher rates of pCR to durvalumab and chemotherapy in TNBC.