KW-2478 (CAS 819812-04-9)

KW-2478 is a novel, non-ansamycin, potent Hsp90 inhibitor (IC50 of 3.8 nM). KW-2478 is a novel non-purine analogue antagonist for Hsp90. KW-2478 suppresses the binding of bRD to HSP90α in concentration-dependent manner. KW-2478 indicates a potent anti-cancer activity in vitro. KW-2478 clearly prevents cancer cell growth in B-cell lymphoma (EC50 of 101-252), mantle cell lymphoma (EC50 of 81.4-91.4) and multiple myeloma (EC50 of 120-622 nM). KW-2478 also shows potent growth inhibitory activity in primary CLL (EC50 of 40-170 nM) and NHL (EC50 of 200-400 nM) cells. KW-2478 depletes the Hsp90 client Cdk9, a transcriptional kinase, and the phosphorylated 4E-BP1, a translational inhibitor. Both inhibitory effects of KW-2478 on such transcriptional and translational pathways have been shown to reduce c-Maf and cyclin D1 expression. In NCI-H929 s.c. inoculated model, KW-2478 displayed a significant inhibition of tumor growth and induced the degradation of client proteins in tumors.