FIELD: chemistry.SUBSTANCE: invention relates to a novel derivative of 1,5- and 1,7-naphthyridine of the formulasor ,as well as to its tautomeric or isomeric form, and a pharmaceutically acceptable salt, wherein X1 is N and X2 is CR3a or X2 is N and X1 is CR3a Each R2 is independently selected from halogen and C1-4alkoxy Y is -E-D D is a 5- or 6-membered aromatic monocyclic heterocyclyl containing one or two N atoms, wherein said heterocyclyl may be optionally substituted with one or two R1 groups E is a chain R1 is C1-6alkyl R3a is hydrogen or chlorine R3 is C2-6alkynyl, halo C1-6alkyl, hydroxyC1-6alkyl, cyano C1-6alkyl, C1-6alkoxyC1-6alkyl, C1-6alkyl, substituted R9, C1-6alkyl substituted with -NR10R11, C1-6alkyl substituted with -C(=O)-NR10R11, R13 R9 is a 5- or 6-membered saturated or aromatic monocyclic heterocyclyl containing one, two or three heteroatoms selected from N or O, wherein mentioned 5- or 6-membered monocyclic heterocyclyl is optionally and independently substituted with 1 or 2 substituents, wherein each substituent is independently selected from =O, C1-4alkyl, -S(=O)2-NR14R15 and phenyl C1-6alkyl R10 and R11 are each independently hydrogen, C1-6alkyl, C1-6alkyl substituted with -NR14R15 R13 is a saturated 6-membered monocyclic heterocyclyl containing one N atom R14 and R15 are each independently hydrogen or C1-4alkyl N is independently an integer of 2, 3 or 4. The invention also relates to a pharmaceutical composition based on a compound of formulas (IA) or (IB), the use of mentioned compound, a method for treating or preventing a condition mediated by FGFR kinase, a product based on a compound of formulas (IA) or (IB).EFFECT: new naphthyridine derivatives, useful in the treatment of cancer, have been obtained.36 cl, 4 tbl, 38 exИзобретение относится к области органической химии, а именно к новому производному 1,5- и 1,7-нафтиридина формул (I-A) или (I-B), а также к его таутомерной или изомерной форме, и фармацевтически приемлемой соли, где X1 пре
