Abstract: N-terminal substituted dipeptide nitriles as defined are useful as inhibitors of cysteine cathepsins, e.g. cathepsins B, K, L and S, and can be used for the treatment of cysteine cathepsin dependent diseases and conditions, including inflammation, rheumatoid arthritis, osteoarthritis, osteoporosis, tumors (especially tumor invasion and tumor metastasis), coronary disease, atherosclerosis (including atherosclerotic plaque rupture and destabilization). Particular dipeptide nitriles are compounds of formula I, or physiologically-acceptable and -cleavable esters or a salts thereof wherein: the symbols are as defined. In particular it has been found that by appropriate choice of groups R, R2, R3, R4, R5, X1, Y and L, the relative selectivity of the compounds as inhibitors of the various cysteine cathepsin types, e.g. cathepsins B, K, L and S may be altered, e.g. to obtain inhibitors which selectively inhibit a particular cathepsin type or combination of cathepsin types.

Abstract: Compound of the formula wherein R represents OH or NHOH; R1 represents hydrogen, optically substituted lower alkyl, aryl-lower alkyl, cycloalkyl-lower alkyl, or acyl derived from a carboxylic acid, from a carbonic acid, from a carbamic acid or from a sulfonic acid; R2 represents biarylsulfonyl or aryloxyrylsulfonyl; R3 represents hydrogen, optionally substituted lower alkyl, aryl-lower alkyl, cycloalkyl-lower alkyl or acyl derived from a carboxylic acid, from a carbonic acid or from a carbamic acid; R4 and R5 represent independently hydrogen, lower alkyl, lower alkoxycarbonyl, aryl-lower alkyl or cycloalkyl-lower alkyl; m is zero, 1, 2 or 3; pharmaceutically acceptable prodrug derivatives thereof; pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising said compounds; and their use for inhibiting matrix degrading metalloproteinases and preventing or treating matrix metalloproteinase dependent conditions in mammals.