Propranolol and Pembrolizumab for Tumor Re-sensitization and Treatment of Patients With Checkpoint Inhibitor Refractory Metastatic or Unresectable Triple Negative Breast Cancer

This phase II trial tests how well propranolol and pembrolizumab work to cause tumor re-sensitization and therefore treatment in patients with triple negative breast cancer that has not responded to previous checkpoint inhibitor therapy (refractory), cannot be removed by surgery (unresectable) or has spread from where it first started (primary site) to other places in the body (metastatic). Propranolol is a drug that is classified as a beta-blocker. Beta-blockers affect the heart and circulation. Beta-blockers, like propranolol, may help to counteract effects of certain stress hormones produced by the body during cancer treatment and may increase the effectiveness of the pembrolizumab. Pembrolizumab is a drug that is classified as an immune checkpoint inhibitor. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Propranolol may be able to re-sensitize the cells of the immune system to respond to the checkpoint inhibitor pembrolizumab in patients with checkpoint inhibitor refractory metastatic or unresectable triple negative breast cancer.