Abstract
IPH5201 treatment decreases tumoral CD39 enzymatic activity. The Wachstein–Meisel assay detects the presence of phosphates hydrolyzed from ATP due to enzymatic activity of CD39. A, Representative histology images of tumor tissues with reduction in CD39 enzymatic activity after treatment with IPH5201. B, Enzymatic activity was assessed by semi-quantitative scoring methodology for tumor, stroma, and vasculature. The pathologist conducted an overall assessment to determine whether a significant decrease was present on day 15 compared with screening biopsies.