Di(arylamino)aryl compound

A method for preventing 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, which comprises administering an effective amount of a compound of formula (I) or a salt thereof to a patient:

• wherein:
• —X— represents
• (1) a group of formula (II), or
• (2) a group of formula (III)
• —R5 represents
• (1) —H,
• (2) —OH,
• (3) halogen,
• (4) lower alkyl which may be substituted with one or more halogens,
• (5) O-lower alkyl which may be substituted with one or more halogens,
• (6) —S-lower alkyl,
• (7) cyano,
• (8) amino which may be substituted with one or two lower alkyls, or
• (9) cyclic amino which may be substituted with one or more groups selected from the group consisting of lower alkyl, oxo, —OH, —O-lower alkyl, and amino which may be substituted with one or two lower alkyls (provided that the triazine ring to which —R5 is attached is attached to the nitrogen atom in the cyclic amino),
• —R6a, —R6b, —R6c and —R6d, K which may be the same or different, each represent
• (1) —H,
• (2) halogen,
• (3) lower alkyl which may be substituted with one or more halogens,
• (4) O-lower alkyl which may be substituted with one or more halogens,
• (5) —S-lower alkyl, or
• (6) cyano,
• —W represents
• a group represented by -A-B,
• -A- is —S(═O)2—,
• -B is isopropyl,
• —R1a, —R1b, —R1c and —R1d are each —H, —R2 is —O-methyl, —R4 is —H, and —R3 is 4-(4-methylpiperazin-1-yl)piperidin-1-yl.