2-heteroaryl-3-oxo-2,3-dihydropyridazine-4-carboxamides for the treatment of cancer

A compound of formula (I):

• wherein
• R1 is C2-C6-hydroxyalkyl, wherein said C2-C6-hydroxyalkyl groups are optionally substituted once with cyano, —COOR10, —CONR11R12, C1-C4-alkoxy or C3-C6-cycloalkyl and optionally one to three times with halogen, or
• C3-C6-cycloalkyl substituted once with hydroxy and optionally once with C1-C3-alkyl and/or one to three times with halogen, or
• C3-C6-cycloalkyl-C1-C3-alkyl substituted once with hydroxy and optionally once with C1-C3-alkyl and/or one to three times with halogen, or
• (C3-C6-cycloalkyl)2-C1-C3-alkyl substituted once with hydroxy and optionally once with C1-C3-alkyl and/or one to three times with halogen, or
• 4- to 6-membered heterocycloalkyl substituted once with hydroxy and optionally once with C1-C3-alkyl and/or one to three times with halogen;
• R2 is chloro, cyano, dimethylamino, methyl, fluoromethyl, difluoromethyl, trifluoromethyl, methoxy, difluoromethoxy or trifluoromethoxy;
• R3 is hydrogen, fluoro, chloro or methyl;
• R4 is hydrogen or fluoro;
• R5 is monocyclic heteroaryl, which is optionally substituted one to three times, independently from each other, with R6;
• R6 is C1-C4-alkyl, C1-C4-haloalkyl, C3-C6-cycloalkyl, C1-C4-alkoxy, halogen or cyano;
• X is CH;
• R10 is C1-C4-alkyl;
• and
• R11 and R12 are the same or different and are independently hydrogen or C1-C3-alkyl, or
• R11 and R12 together with the nitrogen atom to which they are attached form a 4- to 6-membered nitrogen containing heterocyclic ring, said ring optionally containing one additional heteroatom selected from O, S, NH, NRa in which Ra represents a C1-C4-alkyl group,
• or a polymorph, an enantiomer, a diastereomer, a racemate, a tautomer, an N-oxide, a hydrate, a solvate, a physiologically acceptable salt, a solvate of the physiologically acceptable salt, or a mixture of the same.