GDC-0152

GDC-0152 is a potent IAPs inhibitor, and binds to the BIR3 domains of XIAP, cIAP1, cIAP2 and the BIR domain of ML-IAP with K_i values of 28 nM, 17 nM, 43 nM and 14 nM, respectively. IC50 & Target: Ki: 28 nM (XIAP BIR3), 14 nM (MLIAP-BIR3), 17 nM (cIAP1-BIR3), 43 nM (cIAP2-BIR3) In Vitro: GDC-0152 can block protein−protein interactions that involve IAP proteins and pro-apoptotic molecules. Using transiently transfected HEK293T cells, GDC-0152 is shown to disrupt XIAP binding to partially processed caspase-9 and to disrupt the association of ML-IAP, cIAP1, and cIAP2 with Smac. In melanoma SK-MEL28 cells, the endogenous association of ML-IAP and Smac is also effectively abolished by GDC-0152. GDC-0152 leads to a decrease in cell viability in the MDA-MB-231 breast cancer cell line, while having no effect on normal human mammary epithelial cells (HMEC). GDC-0152 is found to activate caspases 3 and 7 in a dose- and time-dependent manner. GDC-0152 is shown to induce rapid degradation of cIAP1 in A2058 melanoma cells. It effectively induces degradation of cIAP1 at concentrations as low as 10 nM, consistent with its affinity for cIAP1^[1]. In Vivo: GDC-0152 has moderate predicted hepatic clearance based on metabolic stability assays conducted using human liver microsomes. Plasma−protein binding of GDC-0152 is moderate and comparable among mice (88−91%), rats (89−91%), dogs (81−90%), monkeys (76−85%), and humans (75−83%) over the range of concentrations investigated (0.1−100 μM); higher plasma−protein binding is observed in rabbits (95−96%). GDC-0152 does not preferentially distribute to red blood cells with blood−plasma partition ratios ranging from 0.6 to 1.1 in all species tested. The pharmacokinetics for GDC-0152 is achieved with a C max of 53.7 μM and AUC of 203.5 h·μM^[1].