A mono-ADP-ribosyltransferase (mARTD) inhibitor compound having i) a general formula wherein: the CLOSURE structure is absent and is replaced by -H on a carbon atom of the phenyl group and by -H 2 on the nitrogen atom; L represents a linker of 1 or 2 linking atom(s) in a linear or in a branched conformation, and being selected from the group consisting of: C, O, N or S, wherein at least one of the linking atoms is oxygen, and when one of the linking atoms is N, it is in form of NH or N(-CH 3), and when one of the linking atoms is C, it is in the form of C(=O) or CH 2; R is a saturated or unsaturated cycloalkyl consisting of 1 monocyclic ring, or an unsaturated heterocyclic ring system consisting of 1 heterocyclic ring, wherein said cycloalkyl or ring system may further contain one substituent selected from a group consisting of: H, F, Cl, Br, I, C 1-3 alkyl, halogen-substituted C 1-3 alkyl, C 1-3 alkoxy, halogen-substituted C 1-3 alkoxy, -CN, -OH, -COOH, -CONH 2 and -NO 2; or ii) a general formula wherein: the CLOSURE structure is absent and is replaced by -H on a carbon atom of the phenyl group and by -H 2 on the nitrogen atom; L represents a linker of 1 or 2 linking atom(s) in a linear or in a branched conformation, said atom(s) being selected from the group consisting of: C, O, N or S wherein at least one of the linking atoms is oxygen, and when one of the linking atoms is N, it is in form of NH or N(-CH 3), and when one of the linking atoms is C, it is in the form of C(=O) or CH 2; and R1 is absent or on 2, 3 or 4 position of the phenyl group and is selected from the group consisting of: H, F, Cl, Br, I, C 1-3 alkyl, halogen-substituted C 1-3 alkyl, C 1-3 alkoxy, halogen-substituted C 1-3 alkoxy, -CN, -OH, -COOH, -CONH 2 and -NO 2; or a tautomer, stereoisomer or a pharmaceutically acceptable salt thereof; for use in the treatment of cancer or an inflammatory disorder. the CLOSURE structure is absent and is replaced by -H on a carbon atom of the phenyl group and by -H 2 on the nitrogen atom; L represents a linker of 1 or 2 linking atom(s) in a linear or in a branched conformation, and being selected from the group consisting of: C, O, N or S, wherein at least one of the linking atoms is oxygen, and when one of the linking atoms is N, it is in form of NH or N(-CH 3), and when one of the linking atoms is C, it is in the form of C(=O) or CH 2; R is a saturated or unsaturated cycloalkyl consisting of 1 monocyclic ring, or an unsaturated heterocyclic ring system consisting of 1 heterocyclic ring, wherein said cycloalkyl or ring system may further contain one substituent selected from a group consisting of: H, F, Cl, Br, I, C 1-3 alkyl, halogen-substituted C 1-3 alkyl, C 1-3 alkoxy, halogen-substituted C 1-3 alkoxy, -CN, -OH, -COOH, -CONH 2 and -NO 2; or ii) a general formula the CLOSURE structure is absent and is replaced by -H on a carbon atom of the phenyl group and by -H 2 on the nitrogen atom; L represents a linker of 1 or 2 linking atom(s) in a linear or in a branched conformation, said atom(s) being selected from the group consisting of: C, O, N or S wherein at least one of the linking atoms is oxygen, and when one of the linking atoms is N, it is in form of NH or N(-CH 3), and when one of the linking atoms is C, it is in the form of C(=O) or CH 2; and R1 is absent or on 2, 3 or 4 position of the phenyl group and is selected from the group consisting of: H, F, Cl, Br, I, C 1-3 alkyl, halogen-substituted C 1-3 alkyl, C 1-3 alkoxy, halogen-substituted C 1-3 alkoxy, -CN, -OH, -COOH, -CONH 2 and -NO 2; or a tautomer, stereoisomer or a pharmaceutically acceptable salt thereof; for use in the treatment of cancer or an inflammatory disorder.