Inhibitory activity of MLN518 on colony formation by AML blasts. AML cells expressing (A) FLT3 ITD or (B) wild-type FLT3 were plated in methylcellulose in the presence of cytokines, and graded concentration of MLN518 and colonies were counted after 7 to 14 days. Results are plotted as a function of MLN518 concentration versus the percentage of inhibition of colony formation. Data points represent means of individual patient samples. Assays were performed in duplicate.