PF-04929113

PF-04929113 is a prodrug for the Hsp90 inhibitor, PF-04958473 (SNX-2112). It binds both Hsp90α and Hsp90β with an IC50 value of 30 nM. PF-04929113, is rapidly absorbed and converted into the active inhibitor after oral administration. The active inhibitor causes degradation of Hsp90 client proteins, including HER2, and reduces phosphorylation of downstream kinases, including Akt and ERK1/2, leading to apoptosis in cancer cells.