Substituted quinoline derivative

A compound of formula (I) or a salt thereof:

• wherein,
• R1a and R1b each are the same or different, and are H, optionally substituted C1-6 alkyl, halogen, hydroxy, or —O-(optionally substituted C1-6 alkyl), and when R1a and R1b are attached to the same carbon atom, R1a and R1b may be linked to each other to form C3-8 cycloalkyl group together with the carbon atom to which R1a and R1b are attached,
• R2 is H, optionally substituted C1-6 alkyl, halogen, cyano, or —O-(optionally substituted C1-6 alkyl),
• R3 is H or halogen,
• R4 is H, methyl, or halogen,
• R5 is methyl, ethyl, or fluoromethyl,
• X is N or CRX and Y is N or CRY, provided that X and Y are not CRX and CRY at the same time,
• RX is H or halogen,
• RY is H or halogen,
• L is a bond, C1-6 alkylene, —O—(C1-6 alkylene), C2-6 alkenylene, C3-8 cycloalkylene, or C4-8 cycloalkenylene,
• Z is —COOH or —CONRZ1RZ2, or
• L and Z may together form optionally substituted C1-6 alkyl, —O-(optionally substituted C1-6 alkyl), or optionally substituted 3- to 8-membered heterocyclic ring group comprising 1 to 2 nitrogen atoms,
• RZ1 is optionally substituted C1-6 alkyl, optionally substituted 3- to 8-membered heterocyclic ring group comprising 1 to 2 nitrogen atoms, or —SO2—RZ3,
• RZ3 is C1-6 alkyl or C3-8 Cycloalkyl,
• RZ2 is H or C1-6 alkyl, or
• RZ1 and R72 may be linked to each other to form optionally substituted 3- to 8-membered heterocyclic ring group comprising 1 to 2 nitrogen atoms together with the nitrogen atom to which RZ1 and RZ2 are attached, and,
• n is 0 or 1.