IRAK1/4/pan-FLT3 Kinase Inhibitors with Reduced hERG Block as Treatments for Acute Myeloid Leukemia

We report the optimization of a series of IRAK1/4/pan-FLT3 kinase inhibitors. These efforts have produced a key compound <b>27</b> that displays potent and selective inhibition of IRAK1, IRAK4, and FLT3, reduced block of hERG, and good pharmacokinetic properties. In a mouse xenograft model of acute myeloid leukemia (AML), <b>27</b> produces survival prolongation superior to that of gilteritinib, the leading FDA-approved FLT3 inhibitor currently used to treat AML.