A compound of Formula (I) and pharmaceutically and/or veterinarily acceptable derivatives thereof, wherein: R 1 is H, C 1-6 alkyl, - C(A)D, C 3-8 cycloalkyl, aryl, het, aryl-C 1-4 alkyl or het-C 1 - 4 alkyl, wherein the cycloalkyl, aryl or het groups are optionally substituted by at least one substituent independently selected from C 1-8 allkyl, C 1-8 alkoxy, OH, halo, CF 3 , OCHF 2 , OCF3, SCF 3 , hydroxy-C 1-6 alkyl, C l-4 alkoxy-C 1-6 alkyl and C 1-4 alkyl-S-C 1-4 alkyl; A is S or O; D is H, C 1-6 alkyl, aryl, het, aryl-C 1-4 alkyl or het-C 1-4 alkyl; R 2 represents aryl 1 or het 1 , each of which is substituted by at least one substituent independently selected from B, provided that when R 2 is substituted by halo then it is also substituted with at least one other substituent independently selected from B other than halo; B represents aryl 2 , het 2 , Oaryl 2 , Ohet 2 , Saryl 2 , Shet 2 , SC 1-6 alkyl, halogen, CHF 2 , OCHF 2 , CF 2 CF 3 , CH 2 CF 3 , CF2CH 3 , aryl 2 -C 1-4 alkyl, C 3-6 cycloalkyl, C 3-6 cycloalkyl-C 1-4 alkyl, C 3-6 cycloalkyl­C 1-4 alkoxy, C 3-6 cycloalkyl-O-C 1-4 alkyl, C 3-6 cycloalkyl-C 1-4 alkoxy-C 1-4 alkyl, OC 3-6 cycloalkyl, SC 3-6 cycloalkyl; wherein the aryl 2 and het 2 groups are optionally substituted by at least one group selected from C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 alkoxy, OC 3-6 cycloalkyl, halo, CN, OH, CF 3 , CHF 2 , OCF 3 , OCHF 2 , hydroxyC 1 $alkyl, C 1-4 alkoxy-C 1-4 alkyl, SC 1-6 alkyl and SCF 3 ; n is 1 or 2, provided that when n is 1, m is 0 or 1 and when n is 2, m is 0, wherein if m is 0, then * represents a chiral centre; R 3 is H, C 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 cycloalkyl­C 1-6 alkyl, aryl 3 , het 3 , aryl 3 -C 1-4 alkyl or het 3 -C 1 4alkyl, wherein the C 3-8 cycloalkyl, aryl 3 or het 3 groups are optionally substituted by at least one substituent independently selected from C 1-6 alkyl, C 1-6 alkoxy, CN, OH, halo, CF 3 , OCF 3 , SCF 3 , hydroxy-C 1-6 alkyl, C 1-4 alkoxy - C 1-6 alkyl and C 1-4 alkyl-S-C 1-4 alkyl; at each occurrence aryl, aryl 1 , aryl 2 and aryl 3 independently represent phenyl, naphthyl, anthracyl or phenanthryl; het 1 represents an aromatic 5- or 6- membered heterocycle which contains at least one N, O or S heteroatom, optionally fused to an aryl group; at each occurrence het, het 2 , and het 3 independently represents an aromatic or non-aromatic 4-, 5- or 6- membered heterocycle which contains at least one N, O or S heteroatom, optionally fused to a 5- or 6- membered carbocyclic group or a second 4-, 5- or 6­membered heterocycle which contains at least one N, 0 or S heteroatom.