3-Hydroxy Midostaurin (CGP 52421), a metabolite of PKC412, effectively inhibits FMS-like tyrosine kinase-3 (FLT3) autophosphorylation with IC50s 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[1].
[1]. Levis M, et al. Plasma inhibitory activity (PIA): a pharmacodynamic assay reveals insights into the basis for cytotoxic response to FLT3 inhibitors. Blood. 2006 Nov 15;108(10):3477-83.