Abstract A067: PD-1 blockade enhances OX40 expression on regulatory T-cells and decreases suppressive function through induction of phospho-STAT3 signaling

Blockade of the co-inhibitory receptor PD-1 has had unprecedented success in the treatment of metastatic melanoma, with response rates of approximately 40% in previously untreated patients. However, since the majority of patients fail to respond, a better understanding of the mechanisms of action involved in response/resistance and novel approaches to overcome resistance are needed. We evaluated T-cells present in peripheral blood samples of...