Inhibition of cellular proliferation of mutant-FLT3-expressing AML patient cells by NVP-AST487. (A) Three-day treatment of AML FLT3-ITD–expressing patient cells versus FLT3-ITD-Ba/F3 cells with NVP-AST487. Experiments were performed 1 time for each AML patient sample. Cell viability was determined by the Trypan blue exclusion. (B) Treatment of an AML peripheral blood sample with NVP-AST487 and PKC412, respectively. This sample tested positive for harboring both the FLT3-ITD mutation and the D835Y mutation. Cell viability was determined by Trypan blue exclusion. (C-E) Treatment of AML bone marrow samples with NVP-AST487 and PKC412, respectively. These samples tested negative for harboring the FLT3 mutation. Cell viability was determined by Trypan blue exclusion.