NVP-CGM097 binds to human MDM2 with an IC50 of 1.7 nM and shows high selectivity over MDM4 (IC50=2000 nM). NVP-CGM097 is about four times more potent than Nutlin-3a (IC50=8 nM). In addition, NVP-CGM097 shows no significant activity against Bcl-2:Bak, Bcl-2:Bad, Mcl-1:Bak, Mcl-1:NOXA, XIAP:BIR3, and c-IAP:BIR3 protein-protein interactions. NVP-CGM097 significantly inhibits the proliferation of cells expressing wild-type p53, while sparing the p53 null cells with a 35-58-fold difference. NVP-CGM097 is able to significantly redistribute wild-type p53 into the cell nucleus with an IC50 of 0.224 μM, demonstrating its ability to inhibit the p53:MDM2 interaction in living cells. In addition, NVP-CGM097 activity against the p53:MDM2 interaction is assessed in proliferation assays using either wild-type p53 or p53 null cells. NVP-CGM097 significantly inhibits the proliferation of cells expressing wild-type p53, while sparing the p53 null cells with a 35-58-fold difference. NVP-CGM097 inhibtis HCT116 (p53) with IC50 of 454±136 nM.