Substituted bicyclic heterocyclic compounds as gamma secretase modulators

A compound of formula (I)

• or a stereoisomeric form thereof, wherein
• Het1 is a 5-membered or 6-membered aromatic heterocycle,
• having formula (a-1), (a-2), (a-3), (a-4) or (a-5):
• R0 is H or C1-4alkyl;
• R1 is H, C1-4alkyl or C1-4alkyloxyC1-4alkyl;
• R2 is C1-4alkyl;
• X is O or S;
• G1 is CH or N;
• G2 is CH, N or C substituted with C1-4alkyl;
• provided that G1 and G2 are not simultaneously N;
• G3 is CH or N;
• R10a and R10b each independently are hydrogen or C1-4alkyl;
• A1 is CR3 or N;
• wherein R3 is H, halo or C1-4alkyloxy;
• A2, A3 and A4 each independently are CH, CF or N;
• provided that maximum two of A1, A2, A3 and A4 are N;
• Het2 is a 9-membered bicyclic aromatic heterocycle, having formula (b-2):
• Y1 is CH;
• Y2 is CR4b ;
• Y3 is CH;
• R4b is H;
• halo;
• C1-4alkyloxy;
• cyano;
• cycloC3-7alkyl;
• or C1-4alkyl optionally substituted with one or more substituents each independently selected from the group consisting of halo and amino;
• R6b is C2-6alkyl substituted with one or more halo substituents;
• C1-6alkyl optionally substituted with one or more substituents each independently selected from the group consisting of piperidinyl, Ar, C1-6alkyloxy, tetrahydropyranyl, cycloC3-7alkyloxy, and cycloC3-7alkyl;
• cycloC3-7alkyl;
• cycloC3-7alkyl substituted with one or more phenyl substituents optionally substituted with one or more halo substituents;
• piperidinyl;
• morpholinyl;
• pyrrolidinyl;
• NR8R9;
• tetrahydropyranyl;
• O—Ar;
• C1-6alkyloxy;
• C1-6alkylthio;
• Ar;
• CH2—O—Ar;
• S—Ar;
• NCH3—Ar;
• or NH—Ar;
• wherein each piperidinyl, morpholinyl, and pyrrolidinyl may optionally be substituted with one or more substituents each independently selected from the group consisting of C1-4alkyl, C2-6alkenyl, C1-4alkylcarbonyl, halo, and C1-4alkyloxycarbonyl;
• wherein each Ar independently is phenyl optionally substituted with one or more substituents each independently selected from the group consisting of halo, C1-4alkyloxy cyano, NR8R9, morpholinyl, C1-4alkyl, and C1-4alkyl substituted with one or more halo substituents;
• pyridinyl optionally substituted with one or more substituents each independently selected from the group consisting of halo, C1-4alkyloxy, cyano, C1-4alkyl, and C1-4alkyl substituted with one or more halo substituents;
• oxazolyl optionally substituted with one or more C1-4alkyl substituents;
• or thienyl optionally substituted with one or more halo substituents;
• each R8 independently is H or C1-4alkyl;
• each R9 independently is H or C1-4alkyl;
• R7 is H, C1-6alkyl optionally substituted with one or more substituents each independently selected from the group consisting of halo, phenyl, and C1-4alkyloxy;
• or a pharmaceutically acceptable addition salt or a solvate thereof.