The present invention provides a compound which is useful as an inhibitor against the kinase activity of EML4-ALK fusion proteins and mutant EGFR proteins.As a result of extensive and intensive studies on compounds having an inhibitory effect against the kinase activity of EML4-ALK fusion proteins and mutant EGFR proteins, the inventors of the present invention have found that the di(arylamino)aryl compound of the present invention has inhibitory activity against the kinase activity of EML4-ALK fusion proteins and mutant EGFR proteins. This finding led to the completion of the present invention. The compound of the present invention can be used as a pharmaceutical composition for preventing and/or treating cancer, lung cancer, non-small cell lung cancer, small cell lung cancer, EML4-ALK fusion polynucleotide-positive and/or mutant EGFR polynucleotide-positive cancer, EML4-ALK fusion polynucleotide-positive and/or mutant EGFR polynucleotide-positive lung cancer, or EML4-ALK fusion polynucleotide-positive and/or mutant EGFR polynucleotide-positive non-small cell lung cancer, etc.
