Compounds of Formula (II) wherein R is H； and R is C-Calkyl, Carbocyclyl or Het； or R and R together define a saturated cyclic amine with 3-6 ring atoms； R and R are independently H, halo, C-Calkyl, C-Chaloalkyl or C-Calkoxy, or R and R together with the carbon atom to which they are attached form a C-Ccycloalkyl； R is a branched C-C alkyl chain, C-Chaloalkyl or -CHC-C cycloalkyl； R is C-Calkyl, C-Chaloalkyl or oxetany-3-yl. for use in the prophylaxis or treatment of a disorder characterised by inappropriate expression or activation of cathepsin S.
