Fig. 1: Identification of gilteritinib as an inhibitor of ALK-rearranged cancer cells.

a Relative cell viability of parental (with IL-3), EML4-ALK wild-type (WT), EML4-ALK I1171N + F1174I, and EML4-ALK I1171N + L1198H Ba/F3 cells treated with 50 nM of the indicated inhibitors. Cell viability was analyzed using the CellTiter-Glo assay and calculated relative to the viability of dimethyl sulfoxide-treated Ba/F3 cells. b The suppression of phospho-ALK in I1171N + F1174I, I1171N + L1198H mutation-expressing Ba/F3 cells was evaluated using western blotting. Cells were treated with the indicated concentrations of gilteritinib for 3 h (n = 2). c The suppression of phospho-ALK and its downstream signals in H3122 parental cells and I1171N + F1174I compound mutation-expressing cells were evaluated using western blotting. Cells were treated with the indicated concentrations of inhibitors for 6 h (n = 2). d The evaluation of the inhibitory activity of gilteritinib in the in vitro kinase assay using the ADP-Glo assay kit showed a dose-dependent decrease in ALK activity with gilteritinib according to the increase of ATP concentration. N = 3 independent samples examined over three independent experiments and representative experiment data are presented as mean values ± SD. e Volcano plot displaying the −log₁₀ (p-value) versus log₂ (gilteritinib treatment/DMSO treatment) for all quantified phosphopeptides. The red diamond indicates phospho-ALK.