Ceritinib is a potent inhibitor against ALK with IC50 of 0.2 nM in cell-free assays. Ceritinib (LDK378) also inhibits IGF-1R, InsR, STK22D and FLT3 with IC50 of 8 nM, 7 nM, 23 nM and 60 nM, respectively. Phase 3.