NVP-AUY922 is a highly potent HSP90 inhibitor for HSP90α/β with IC50 of 13 nM /21 nM, weaker potency against the HSP90 family members GRP94 and TRAP-1, exhibits the tightest binding of any small-molecule HSP90 ligand.

Hsp90 is a molecular chaperone of many different kinases, transcription factors, and hormone receptors involved in signal transduction, cell cycle regulation, and apoptosis. In addition to its important function in normal cell homeostasis, a high affinity form of Hsp90 is prevalent in tumor cells. Hsp90 inhibition has been associated with the degradation of oncogenic client proteins. NVP-AUY922 is a Hsp90 inhibitor (IC50 = 21 nM in a FP binding assay) that prevents the proliferation of a range of human cancer cell lines in vitro with GI50s averaging 9 nM.In a human colon cancer xenograft model, 50 mg/kg NVP-AUY922 inhibits tumor growth by ~50% compared to vehicle controls.Unlike some first generation Hsp90 inhibitors that are quickly glucuronidated, NVP-AUY922 is retained in tumors in vivo when administered at 4 mg/kg i.p. by cassette dosing in tumor-bearing mice.