Compounds with tubulin polymerisation inhibitory activity and immunomodulatory properties

A compound of following formula (I):

• in which:
• X represents a —CH— group or a nitrogen atom,
• R1 represents a hydrogen atom, a halogen atom, a (C1-C6)alkyl group, a —CN group or a —CF3 group,
• R2 represents a hydrogen atom, a (C1-C6)alkyl group, an aryl-(C1-C6)alkyl group, or a —COR21 group with R21 representing a (C1-C6)alkyl group or an aryl group,
• R3 represents a (C1-C6)alkyl group, an aryl-(C1-C6)alkyl group or a —COR31 group with R31 representing a (C1-C6)alkyl group or an aryl group,
• R41, R42, R43 and R44 represent independently of each other a hydrogen atom;
• a halogen atom;
• —OR45;
• —SR45;
• —NR45R46;
• —NO2;
• or a (C1-C6)alkyl group optionally substituted by one or more substituents selected from among a halogen atom, —OR45, —SR45, —NR45R46 and —NO2, with R45 and R46 representing independently of each other a hydrogen atom, a (C1-C6)alkyl group, a —CF3 group or a —COR47 group with R47 representing a (C1-C6)alkyl group or an aryl group,
• R5 and R6 represent a hydrogen atom or form together a —CR51═CR52—CR53═CR54— chain with R51, R52, R53 and R54 representing independently of each other a hydrogen atom;
• a halogen atom;
• —OR55;
• —SR55;
• —NR55R56;
• —NO2;
• or a (C1-C6)alkyl group optionally substituted by one or more substituents selected from among a halogen atom, —OR55, —SR55, —NR55R56 and —NO2, with R55 and R56 representing independently of each other a hydrogen atom, a (C1-C6)alkyl group, a —CF3 group or a —COR57 group with R57 representing a (C1-C6)alkyl group or an aryl group,
• wherein, when X represents a nitrogen atom, R1 represents a chlorine atom, a —CN group or a —CF3 group, or R5 and R6 form together a —CR51═CR52—CR53═CR54— chain,
• or a pharmaceutically acceptable salt thereof.