Diamino heterocyclic carboxamide compound

A method for preventing or treating cancer, lung cancer, non-small cell lung cancer, small cell lung cancer, EML4-ALK fusion polynucleotide-positive cancer, EML4-ALK fusion polynucleotide-positive lung cancer, or EML4-ALK fusion polynucleotide-positive non-small cell lung cancer, which comprises administering to a patient an effective amount of a compound of formula (I) or a salt thereof:

• wherein the symbols are as defined below:
• —X— is a group of formula (II):
• A is chloro, ethyl, or isopropyl;
• R1 is phenyl in which the carbon at the 4-position is substituted with —W—Y—Z and the carbon at the 3-position may be substituted with a group selected from the group consisting of halogen, R00, and —O—R00;
• R00 is lower alkyl which may be substituted with one or more halogens;
• —W— is a bond, piperidine-1,4-diyl, or piperazine-1,4-diyl;
• —Y— is a bond;
• Z is a non-aromatic heterocyclic ring which may be substituted with one or more R00;
• R2 is (i) cycloalkyl which may be substituted with one or more groups selected from the group consisting of —N(lower alkyl)2, lower alkyl, —COO-lower alkyl, —OH, —COOH, —CONH—RZB, and morpholinyl, or (ii) a non-aromatic heterocyclic ring which may be substituted with one or more groups selected from the group consisting of lower alkyl, —CO-lower alkyl, oxo, —CO—RZB, and benzyl;
• RZB is phenyl which may be substituted with a group selected from the group consisting of halogen and —O-lower alkyl;
• and
• R3 is —H.