AUY922 is a synthetic Hsp90 inhibitor. It is not related to the natural products geldanamycin (as is IPI504) or radicicol.
This drug is under development by Novartis.
For information at the manufacturer website click here.
For details about this compound see this link, a paper by Brough et al in the Journal of Medicinal Chemistry.
A Phase II trial is pending for patients with resistant GIST: