Inhibitors of DUX4 induction for regulation of muscle function

1. A method for modulating DUX4 activity in a subject in need thereof comprising administering to the subject in need thereof a composition comprising a compound, or a pharmaceutically acceptable salt thereof, having the structure of Formula (III):

wherein:

Ar is phenyl or 5- or 6-membered heteroaryl;

each R 1 is independently hydrogen, halogen, —CN, —OH, —OR 20 , —SH, —SR 20 , —NO 2 , —NR 21 R 21 , —S(═O) 2 R 20 , —NR 21 S(═O) 2 R 20 , —S(═O)R 20 , —S(═O) 2 NR 21 R 21 , —C(═O)R 20 , —OC(═O)R 20 , —C(═O)OR 21 , —OC(═O)OR 21 , —C(═O)NR 21 R 21 , —OC(═O)NR 21 R 21 , —NR 21 C(═O)NR 21 R 21 , —NR 21 C(═O)R 20 , —NR 21 C(═O)OR 21 , unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted C 2 -C 6 alkenyl, unsubstituted or substituted C 2 -C 6 alkynyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted —C 1 -C 6 -alkylene-cycloalkyl, unsubstituted or substituted —C 1 -C 6 -alkylene-heterocycloalkyl, unsubstituted or substituted —C 1 -C 6 -alkylene-aryl, or unsubstituted or substituted —C 1 -C 6 -alkylene-heteroaryl;

n is 0-5;

L 1 is absent or *—(CR a R b )—C(═O)—, wherein * denotes attachment point to the carbonyl carbon;

R a and R b are independently selected from hydrogen, C 1 -C 6 alkyl, or C 1 -C 6 haloalkyl;

or R a and R b are taken together with the carbon to which they are attached to form a 3-, 4-, 5-, or 6-membered cycloalkyl or a 3-, 4-, 5-, or 6-membered heterocycloalkyl;

each R 2 is independently hydrogen, halogen, —CN, —OH, —OR 20 , —NR 21 R 21 , —C(═O)R 20 , —OC(═O)R 20 , —C(═O)OR 21 , —C(═O)NR 21 R 21 , —NR 21 C(═O)R 20 , C 1 -C 6 alkyl, or C 1 -C 6 haloalkyl;

or two R 2 on adjacent atoms are taken together with the atoms to which they are attached to form an unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl;

m is 0-4;

L 2 is absent, —O—, —O—(C 1 -C 4 alkylene)-, or —NR c —C(═O)—;

each R c is independently selected from hydrogen, C 1 -C 6 alkyl, or C 1 -C 6 haloalkyl;

R 3 is unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl; wherein when R 3 is substituted, it is substituted by 1-3 R 4 ;

each R 4 is independently hydrogen, halogen, —CN, —OH, —OR 20 , —SH, —SR 20 , —NO 2 , —NR 21 R 21 , —S(═O) 2 R 20 , —NR 21 S(═O) 2 R 20 , —S(═O)R 20 , —S(═O) 2 NR 21 R 21 , —C(═O)R 20 , —OC(═O)R 20 , —C(═O)OR 21 , —OC(═O)OR 21 , —C(═O)NR 21 R 21 , —OC(═O)NR 21 R 21 , —NR 21 C(═O)NR 21 R 21 , —NR 21 C(═O)R 20 , —NR 21 C(═O)OR 21 , unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted C 2 -C 6 alkenyl, unsubstituted or substituted C 2 -C 6 alkynyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl;

each R 20 is independently selected from unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted C 2 -C 6 alkenyl, unsubstituted or substituted C 2 -C 6 alkynyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl;

each R 21 is independently selected from hydrogen, unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted C 1 -C 6 alkenyl, unsubstituted or substituted C 1 -C 6 alkynyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl;

or two R 21 on the same N atom are taken together with the N atom to which they are attached to form an unsubstituted or substituted N-containing heterocycle;

wherein when any R 1 , R 2 , R 4 , R 20 , or R 21 is substituted, substituents on the R 1 , R 2 , R 4 , R 20 , or R 21 are independently selected at each occurrence from halogen, —CN, —NO 2 , —OR 22 , —CO 2 R 22 , —C(═O)R 23 , —C(═O)N 22 R 22 , —NR 22 R 22 , —NR 22 C(═O)R 23 , —NR 22 C(═O)OR 22 , —SR 22 , —S(═O)R 23 , —SO 2 R 23 , —SO 2 NR 22 R 22 , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, monocyclic cycloalkyl, monocyclic heterocycloalkyl, phenyl, benzyl, 5-membered heteroaryl, and 6-membered heteroaryl; or two substituents on the same carbon atom are taken together to form a C═O or C═S;

each R 22 is independently selected from hydrogen, C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, phenyl, benzyl, 5-membered heteroaryl, and 6-membered heteroaryl;

or two R 22 groups are taken together with the N atom to which they are attached to form a N-containing heterocycle; and

each R 23 is independently selected from C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, phenyl, benzyl, 5-membered heteroaryl, and 6-membered heteroaryl.

2. The method of claim 1 , wherein the modulating DUX4 activity comprises reducing expression of DUX4.

3. The method of claim 1 , wherein DUX4 expression is monitored by monitoring DUX4 mRNA expression, DUX4 protein expression, or both DUX4 mRNA expression and DUX4 protein expression.

4. The method of claim 1 , wherein the DUX4 target gene is one or more genes selected from the group consisting of CCNA1, KHDC1L, LEUTX, M8D3L2, PRAMEF2, PRAMEF6, SPRYD5, TRIM43, TRIM49, ZNF296, and ZSCAN4.

5. The method of claim 1 , wherein the compound comprises rebastinib, 4-(4-(3-(3-(tert-butyl)-1-(quinolin-6-yl)-1H-pyrazol-5-yl)ureido)-2-methylphenoxy)-N-methylpicolinamide, or 4-(4-(3-(3-(tert-butyl)-1-(1H-indazol-5-yl)-1H-pyrazol-5-yl)ureido)-3-fluorophenoxy)-N-methylpicolinamide.