In particular, ceritinib effectively inhibits ALK harboring L1196M, G1269A, I1171T and S1206Y mutations, and a co-crystal of ceritinib bound to ALK provides structural bases for this increased potency….In the wild-type and I1171T resistant models, ceritinib demonstrated impressive anti-tumor activity, while it was less active in the C1156Y resistant model and was inactive against the G1202R resistant model.