Indole derivatives and uses thereof

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

• wherein:
• L is absent, O, S, NHCO or CONH;
• X is CH or N;
• R1 is H, C1-4alkyl, C1-4haloalkyl, or 3-6 membered cycloalkyl;
• R2 is H, —OH, halo, —CN, nitro, C1-4alkoxy, C1-4alkyl, C1-4alkoxy-C1-4alkyl, C1-4haloalkyl, C1-4hydroxyalkyl, a 5-10 membered heterocyclyl optionally substituted with 1-3 C1-4alkyl groups, —(CH2)n-(6 or 10 membered aryl optionally substituted with 1-3 C1-4alkyl groups), or —(CH2)n-(5-10 membered heteroaryl optionally substituted with 1-3 C1-4alkyl groups);
• R3 is H, halo, —OH, C1-4alkyl, C1-4alkoxy, C1-4haloalkyl or C1-4 haloalkoxy;
• R4 is a substituted C2-4alkynyl, a substituted or unsubstituted 5-10 membered heterocyclyl, a substituted or unsubstituted 5-10 membered heteroaryl, a substituted or unsubstituted 5-10 membered fused heterocyclyl-aryl, a substituted or unsubstituted 5-10 membered fused heterocyclyl-heteroaryl, or a substituted or unsubstituted 6 or 10 membered aryl, wherein when R4 is substituted, R4 is substituted with 1-3 substituents independently selected from halo, —OH, oxo (═O), —CN, nitro, C1-4alkyl, —C1-4alkyl-(3-6 membered cycloalkyl), C1-4alkoxy, —SO2—C1-4alkyl, —SO2—C1-4hydroxyalkyl, —SO2—C1-4alkyl-NR5R6, —NHSO2—C1-4alkyl, C1-4hydroxyalkyl, —SO2NR5R6, —CO—C1-4hydroxyalkyl, —CONR5R6, —CO—C1-4alkyl-NR5R6, —CO—NH—C1-4alkyl-NR5R6, —NR5R6, —C1-4alkyl-NR5R6 and —CO—C1-4alkyl;
• R5 and R6 are each, independently, selected from H, C1-4alkyl, C1-4hydroxyalkyl, —CO—C1-4alkyl and -(4-10 membered heterocyclyl)-C1-4alkyl;
• or R5 and R6, together with the nitrogen atom to which they are attached, form a 5-7 membered heterocyclyl optionally substituted with 1-3 C1-4alkyl groups;
• and
• n is 0 or 1.