WEHI-539 hydrochloride

An apoptosis inducer that selectively targets the anti-apoptotic Bcl-2 family member Bcl-XL with high affinity.

WEHI-539 is an apoptosis inducer that selectively targets the anti-apoptotic Bcl-2 family member Bcl-XL with high affinity (KD = 0.6 nM; 500-fold over Bcl-2 and 400-fold over Bcl-W, Mcl-1 and A1) in a manner distinct from that of ABT-737. WEHI blocks Bcl-XL from targeting the BH3 domain of the pro-apoptotic family member Bim with high potency (IC50 = 1.1 nM), exhibiting no inhibitory potency against Mcl-1-BimBH3 interaction (IC50 >10 μM). WEHI-539 is shown to induce apoptosis in human and murine cultures by selectively antagonizing Bcl-XL prosurvival activity (EC50 <10 nM/Mcl-1-knockout MEF, <0.5 nM/mouse platelets, and <32 nM/human platelets).