P5091

P5091 is a **novel, potent, and selective small molecule inhibitor of ubiquitin-specific protease 7 (USP7)**, a deubiquitinase enzyme. It demonstrates an IC50 of approximately 4.2 µM for USP7 and shows selectivity over other deubiquitinases and cysteine proteases. By inhibiting USP7, P5091 disrupts the stability of multiple oncoproteins and tumor suppressors—such as HDM2 and p21—inducing apoptosis and cytotoxicity particularly in multiple myeloma cells (including those resistant to conventional or bortezomib-based therapies). Preclinical studies have shown that P5091 can inhibit tumor growth, prolong survival, and enhance antitumor immune responses in vivo, with increased efficacy when combined with agents such as lenalidomide, dexamethasone, or HDAC inhibitors. It can also modulate immune activity by influencing cytokine expression and T cell function[1][2][3][4][5].

Other names

1-(5-((2,3-dichlorophenyl)thio)-4-nitrothiophen-2-yl)ethanone