3-Hydroxy Midostaurin (CGP 52421), a metabolite of PKC412, effectively inhibits FMS-like tyrosine kinase-3 (FLT3) autophosphorylation with IC 50 s of approximately 132 nM and 9.8 μM in culture medium and plasma, respectively. 3-Hydroxy Midostaurin is less selective but more cytotoxic than PKC412 In Vitro CGP52421 (200, 400, 600, 800, 1000 nM) is more cytotoxic than PKC412 over the dose range 100 to 500 nM. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 132 nM (FLT3 in culture medium) and 9.8 μM (FLT3 in plasma)