According to the NCI website Ganetespib is a synthetic small-molecule inhibitor of heat shock protein 90 (Hsp90) with potential antineoplastic activity.
Abstract from Molecular Cancer Therapeutics:
Targeted inhibition of the molecular chaperone heat shock protein 90 (Hsp90) results in the simultaneous blockade of multiple oncogenic signaling pathways and has thus emerged as an attractive strategy for the development of novel cancer therapeutics. Ganetespib (formerly known as STA-9090) is a unique resorcinolic triazolone inhibitor of Hsp90 currently in clinical trials for a number of human cancers. Here we show that ganetespib exhibits potent in vitro cytotoxicity in a range of solid and hematological tumor cell lines, including those that express mutated kinases that confer resistance to small molecule tyrosine kinase inhibitors (TKIs). Ganetespib treatment rapidly induced the degradation of known Hsp90 client proteins, displayed superior potency to the ansamycin inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), and exhibited sustained activity even with short exposure times. In vivo, ganetespib demonstrated potent antitumor efficacy in solid and hematological xenograft models of oncogene addiction, as evidenced by significant growth inhibition and/or regressions. Of note, evaluation of the microregional activity of ganetespib in tumor xenografts showed that ganetespib efficiently distributed throughout tumor tissue, including hypoxic regions >150 μm from the microvasculature, to inhibit proliferation and induce apoptosis. Importantly, ganetespib showed no evidence of cardiac or liver toxicity. Taken together, this preclinical activity profile suggests that ganetespib may have broad application for a variety of human malignancies, and with select mechanistic and safety advantages over other first- and second-generation Hsp90 inhibitors. Molecular Cancer Therapeutics