A compound of formula: wherein: k is 0, 1, 2, 3 or 4; m is 0, 1 or 2; n is 0, 1, 2, 3, 4 or 5; q is 0, 1, 2, 3, 4, 5 or 6; A is -O- or -S-; is aryl or N -heteroaryl; R 1 is -O-, -C(R 9) 2 -, -N(R 10)-, -N(R 11)- or -S t (where t is 0, 1 or 2); R 2 is C(R 9); R 3 is hydrogen, alkyl, haloalkyl, optionally substituted aryl or optionally substituted aralkyl; or R 3 is a direct bond to R 4; R 4 is H, optionally substituted alkyl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted cycloalkyl, haloalkyl, -C R 10, -C N(R 10) 2 or -C(=NCN)N(R 10) 2; or R 3 and R 4, together with the nitrogen to which they are both attached, form an optionally substituted N -heterocyclyl or optionally substituted N -heteroaryl; each R 5 and each R 6 are independently hydrogen, alkyl, halo, haloalkyl, nitro, cyano, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; each R 7 is independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; or any two R 7 's on the same carbon may form an oxo and the other R 7 's are independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; or any two R 7 's on different carbons may form an optionally substituted straight or branched alkylene chain optionally containing one or more heteroatoms, and the other R 7 's, if present, are independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; R 8 is a direct bond or an optionally substituted straight or branched divalent hydrocarbon, consisting solely of carbon and hydrogen, containing no unsaturation and having from one to twelve carbon atoms; each R 9 is independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -N(R 10) 2, -N(R 11) 2, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; each R 10 is independently hydrogen, alkyl, haloalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl; and each R 11 is independently -C R 10; -C OR 10, -C N(R 10) 2, -S p R 10 (where p is 1 or 2) or -S p N(R 10) 2 (where p is 1 or 2); as individual stereoisomers, enantiomers or tautomers thereof or mixtures thereof; or as pharmaceutically acceptable salts, or solvates thereof; or 2,5-difluoro-4-((trans-3-(4-fluorophenyl)piperidin-4-yl)methoxy)- N- (1,2,4-thiadiazol-5-yl)benzenesulfonamide, or a salt thereof. k is 0, 1, 2, 3 or 4; m is 0, 1 or 2; n is 0, 1, 2, 3, 4 or 5; q is 0, 1, 2, 3, 4, 5 or 6; A is -O- or -S-; is aryl or N -heteroaryl; R 1 is -O-, -C(R 9) 2 -, -N(R 10)-, -N(R 11)- or -S t (where t is 0, 1 or 2); R 2 is C(R 9); R 3 is hydrogen, alkyl, haloalkyl, optionally substituted aryl or optionally substituted aralkyl; or R 3 is a direct bond to R 4; R 4 is H, optionally substituted alkyl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted cycloalkyl, haloalkyl, -C R 10, -C N(R 10) 2 or -C(=NCN)N(R 10) 2; or R 3 and R 4, together with the nitrogen to which they are both attached, form an optionally substituted N -heterocyclyl or optionally substituted N -heteroaryl; each R 5 and each R 6 are independently hydrogen, alkyl, halo, haloalkyl, nitro, cyano, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; each R 7 is independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; or any two R 7 's on the same carbon may form an oxo and the other R 7 's are independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; or any two R 7 's on different carbons may form an optionally substituted straight or branched alkylene chain optionally containing one or more heteroatoms, and the other R 7 's, if present, are independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; R 8 is a direct bond or an optionally substituted straight or branched divalent hydrocarbon, consisting solely of carbon and hydrogen, containing no unsaturation and having from one to twelve carbon atoms; each R 9 is independently hydrogen, alkyl, halo, haloalkyl, -OR 10, -N(R 10) 2, -N(R 11) 2, -S t R 10 (where t is 0, 1 or 2), -C OR 10, -C R 10 or -C N(R 10) 2; each R 10 is independently hydrogen, alkyl, haloalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl; and each R 11 is independently -C R 10; -C OR 10, -C N(R 10) 2, -S p R 10 (where p is 1 or 2) or -S p N(R 10) 2 (where p is 1 or 2); as individual stereoisomers, enantiomers or tautomers thereof or mixtures thereof; or as pharmaceutically acceptable salts, or solvates thereof; or 2,5-difluoro-4-((trans-3-(4-fluorophenyl)piperidin-4-yl)methoxy)- N- (1,2,4-thiadiazol-5-yl)benzenesulfonamide, or a salt thereof.