P5091 is a selective and inhibitor of ubiquitin-specific protease 7 (USP7) with an IC50 of 4.2 µM. P5091 displays little or no inhibition of other USP variants or proteases such as caspase, cathepsins and serine proteases but does have some activity at USP47. P5091 induces elevated p53 and apoptosis in cancer cell lines and possesses antiangiogenic activity in vivo.
