Therapeutic or prophylactic agent for multiple sclerosis

A therapeutic or prophylactic agent for multiple sclerosis, comprising, as an effective component, a cyclohexane derivative represented by Formula (I):

• wherein
• A is a substituent represented by Formula (IIa) or (IIb):
• R1 and R2 are each independently a hydrogen atom, chlorine atom, C1-C3 haloalkyl, C1-C4 alkyl, C1-C4 alkoxy, or cyano;
• R3 is a hydrogen atom or chlorine atom;
• R4 is a fluorine atom, hydroxymethyl, or hydroxyl;
• R5 and R6 are each independently a hydrogen atom, fluorine atom, C1-C3 haloalkyl, carboxyl, methoxycarbonyl, ethoxycarbonyl, C1-C4 alkoxy, hydroxyl, or C2-C5 alkylcarbonyloxy, or optionally together form oxo;
• R7 and R8 are each independently a hydrogen atom or fluorine atom;
• Y is an oxygen atom or sulfur atom;
• and
• Z is a nitrogen atom or methane
• or a pharmaceutically acceptable salt thereof.

A therapeutic or prophylactic agent for multiple sclerosis, comprising, as an effective component, a cyclohexane derivative represented by Formula (I):

• wherein
• A is a substituent represented by Formula (IIc) or (IId):
• R1 and R2 are each independently a hydrogen atom, chlorine atom, C1-C3 haloalkyl, C1-C4 alkyl, or C1-C4 alkoxy;
• R3 is a hydrogen atom or chlorine atom;
• R4 is a fluorine atom, hydroxymethyl, or hydroxyl;
• R5 and R6 are each independently a hydrogen atom, fluorine atom, C1-C3 haloalkyl, carboxyl, C1-C4 alkoxy, hydroxyl, or C2-C5 alkylcarbonyloxy, or optionally together form oxo;
• Y is an oxygen atom or sulfur atom;
• and
• Z is a nitrogen atom or methane
• or a pharmaceutically acceptable salt thereof.