Abstract
Therapeutic immune checkpoint antibodies promote potentially durable cancer control by modulating key regulatory factors of the endogenous anti-tumor immune response. The first clinical trial data of these agents in breast cancer were presented at the 2014 San Antonio Breast Cancer Symposium, with seemingly modest response rates compared with metastatic melanoma and Hodgkin’s lymphoma. In this article, we review the San Antonio immunotherapy data, drawing key analogies to historical experiences in metastatic melanoma that support an enthusiastic outlook for immunotherapy in breast cancer.