5-[2,4-Dihydroxy-6-(4-nitrophenoxy)phenyl]-N-(1-methyl-4-piperidinyl)-3-isoxazolecarboxamide

nms-e973 is a potent and selective inhibitor of heat shock protein 90 (hsp90) with dc50 value of < 10nm [1].since hsp90 plays an important role in the conformational maturation, stability and function of some oncogenic proteins, the inhibitors of hsp90 are developed as therapeutic for cancers. nms-e973 is a selective inhibitor of hsp90. it binds to hsp90α within the atp binding site with dc50 value of < 10nm. besides that, nms-e973 shows no effect on a panel of 52 various protein kinases such as abl, ack1, akt1 and alk. the ic50 value of it for hsc70 is > 10μm. nms-e973 exerts antiproliferation effects on a2780 tumor cell line and bt-474 breast cancer cell line with ic50 values of 69nm and 110nm, respectively. when treated with mice bearing a2780 xenografts, the intravenous administration of nms-e973 significantly inhibits tumor growth with tgi value of 53% at dose of 30mg/kg. moreover, nms-e973 also displays antitumor activity in tumors resistant to kinase inhibitors such as vemurafenib [1, 2].

Hsp90

[1] brasca m g, mantegani s, amboldi n, et al. discovery of nms-e973 as novel, selective and potent inhibitor of heat shock protein 90 (hsp90). bioorganic & medicinal chemistry, 2013, 21(22): 7047-7063.
[2] fogliatto g, gianellini l, brasca m g, et al. nms-e973, a novel synthetic inhibitor of hsp90 with activity against multiple models of drug resistance to targeted agents, including intracranial metastases. clinical cancer research, 2013, 19(13): 3520-3532.