Pembrolizumab With Carboplatin Compared to Carboplatin Alone in Breast Cancer Patients With Chest Wall Disease

This is a phase II multicenter study including breast cancer patients with chest wall disease that is hormone resistant (estrogen receptor (ER) positive/progesterone receptor (PR) positive/human epidermal growth factor receptor 2 (HER2) negative breast cancer with progressive disease on 2 prior lines of hormonal therapy) or triple negative (ER negative/PR negative/HER2 negative, TNBC). A companion translational study is operating concurrently with the study described above. In this study, biomarker research to be performed on tumor biopsies and peripheral blood samples will be performed to explore the immunologic and genomic mechanism of action underlying treatment with pembrolizumab and carboplatin versus carboplatin alone. This protocol includes tissue and blood correlative exploratory endpoints including changes in tumor PD-L1 (programmed death ligand 1) gene expression, tumor and peripheral blood immune composition and cytokine expression, plasma tumor DNA, circulating tumor cells, and tumor myelocytomatosis (MYC) oncogene expression using tumor biopsy and peripheral blood testing before and after treatment; correlations with these markers and disease control rate will be assessed.