However, we observed that ceritinib did not overcome two crizotinib-resistant ALK mutations, G1202R and F1174C, and one of these mutations were identified in 5 out of 11 biopsies from patients with acquired resistance to ceritinib….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.