Laratinib is a third-generation ALK tyrosine kinase inhibitor (TKI) suitable for treating ALK positive metastatic non-small cell lung cancer (NSCLC) patients whose disease has progressed prior to a) treatment with clotozantinib and at least one other ALK inhibitor. Or b) previously used erlotinib as the first ALK inhibitor for treating metastatic diseases, or c) previously used clotozantinib as the first ALK inhibitor for treating metastatic diseases.