Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: one of R3 and R4 is H, and the other is selected from C1-6-alkyl, C1-6-haloalkyl, C1-6-alkoxy, and C6-12-aralkyl; or R3 and R4 are each independently selected from C1-6-alkyl and halo; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high efficacies for human cathepsin S, excellent selectivity verses other mammalian cathepsins and are useful for treatment of diseases such as rheumatoid arthritis, multiple sclerosis, myasthenia gravis, transplant rejection, diabetes, Sjogrens syndrome, Grave's disease, systemic lupus erythematosis, osteoarthritis, psoriasis, idiopathic thrombocytopenic purpura, allergic rhinitis, asthma, atherosclerosis, obesity, chronic obstructive pulmonary disease and chronic pain.

Abstract: A compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein one of R1 and R2 is H, and the other is selected from C1-8-alkyl, C3-6-cycloalkyl and C1-8-alkyl-C5-10-aryl; R3 is selected from tert-butylmethyl, iso-propylmethyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl and 1-methylcyclopentyl; R9 is selected from the following: wherein: R4 is selected from C1-8-alkyl and C3-8-cycloalkyl; G is selected from: CH, CMe and N; E is selected from: O, S, SO2, NH, NMe and N-oxide (N?O); J and R are independently selected from: CH, N and N-oxide (N?O); and R41 is selected from amino, methylamino, dimethylamino, isopropylamino, isopropyl(methyl)amino, cyclopropylamino, cyclopropyl (methyl) amino, cyclopentylamino, morpholino, piperidin-1-yl, piperidin-1-ylmethyl, morpholinomethyl, 4-methylpiperazin-1-yl, 4-(2-methoxyethyl)piperazin-1-yl, 1-morpholino ethyl, 1-(dimethyl amino)ethyl, 1-(methyl amino)ethyl, 4-fluoro-1-methylpyrrolidin-2-yl, 4,4-difluoropiperi

Abstract: A compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein one of R1 and R2 is H, and the other is selected from C1-8-alkyl, C3-6-cycloalkyl and C1-8-alkyl-C5-10-aryl; R3 is selected from tert-butylmethyl, iso-propylmethyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl and 1-methylcyclopentyl; R9 is selected from the following: wherein: R4 is selected from C1-8-alkyl and C3-8-cycloalkyl; G is selected from: CH, CMe and N; E is selected from: O, S, SO2, NH, NMe and N-oxide (N?O); J and R are independently selected from: CH, N and N-oxide (N?O); and R41 is selected from amino, methylamino, dimethylamino, isopropylamino, isopropyl(methyl)amino, cyclopropylamino, cyclopropyl(methyl)amino, cyclopentylamino, morpholino, piperidin-1-yl, piperidin-1-ylmethyl, morpholinomethyl, 4-methylpiperazin-1-yl, 4-(2-methoxyethyl)piperazin-1-yl, 1-morpholinoethyl, 1-(dimethylamino)ethyl, 1-(methylamino)ethyl, 4-fluoro-1-methylpyrrolidin-2-yl, 4,4-difluoropiperidin-

Abstract: A compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein one of R1 and R2 is H, and the other is selected from C1-8-alkyl, C3-6-cycloalkyl and C1-8-alkyl-C5-10-aryl; R3 is selected from tert-butylmethyl, iso-propylmethyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl and 1-methylcyclopentyl; R9 is selected from the following: wherein: R4 is selected from C1-8-alkyl and C3-8-cycloalkyl; G is selected from: CH, CMe and N; E is selected from: O, S, SO2, NH, NMe and N-oxide (N?O); J and R are independently selected from: CH, N and N-oxide (N?O); and R41 is selected from amino, methylamino, dimethylamino, isopropylamino, isopropyl(methyl)amino, cyclopropylamino, cyclopropyl(methyl)amino, cyclopentylamino, morpholino, piperidin-1-yl, piperidin-1-ylmethyl, morpholinomethyl, 4-methylpiperazin-1-yl, 4-(2-methoxyethyl)piperazin-1-yl, 1-morpholinoethyl, 1-(dimethylamino)ethyl, 1-(methylamino)ethyl, 4-fluoro-1-methylpyrrolidin-2-yl, 4,4-difluoropiperidin-

Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: one of R3 and R4 is H, and the other is selected from C1-6-alkyl, C1-6-haloalkyl, C1-6-alkoxy, and C6-12-aralkyl; or R3 and R4 are each independently selected from C1-6-alkyl and halo; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high efficacies for human cathepsin S, excellent selectivity verses other mammalian cathepsins and are useful for treatment of diseases such as rheumatoid arthritis, multiple sclerosis, myasthenia gravis, transplant rejection, diabetes, Sjogrens syndrome, Grave's disease, systemic lupus erythematosis, osteoarthritis, psoriasis, idiopathic thrombocytopenic purpura, allergic rhinitis, asthma, atherosclerosis, obesity, chronic obstructive pulmonary disease and chronic pain.

Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: R3 is selected from cyclopentyl and cyclohexyl; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high dual efficacies for human cathepsin S and K and are useful for the treatment of rheumatoid arthritis, osteoarthritis, chronic obstructive pulmonary disease (COPD), atherosclerosis, cardiovascular diseases which exhibit significant damage and remodeling of extracellular matrix (ECM) and chronic pain.

Abstract: A compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein one of R1 and R2 is H, and the other is selected from C1-8-alkyl, C3-6-cycloalkyl and C1-8-alkyl-C5-10-aryl; R3 is selected from tert-butylmethyl, iso-propylmethyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl and 1-methylcyclopentyl; R9 is selected from the following: wherein: R4 is selected from C1-8-alkyl and C3-8-cycloalkyl; G is selected from: CH, CMe and N; E is selected from: O, S, SO2, NH, NMe and N-oxide (N?O); J and R are independently selected from: CH, N and N-oxide (N?O); and R41 is selected from amino, methylamino, dimethylamino, isopropylamino, isopropyl(methyl)amino, cyclopropylamino, cyclopropyl(methyl)amino, cyclopentylamino, morpholino, piperidin-1-yl, piperidin-1-ylmethyl, morpholinomethyl, 4-methylpiperazin-1-yl, 4-(2-methoxyethyl)piperazin-1-yl, 1-morpholino ethyl, 1-(dimethylamino)ethyl, 1-(methylamino)ethyl, 4-fluoro-1-methylpyrrolidin-2-yl, 4,4-difluoropiperidin-

Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: R3 is selected from cyclopentyl and cyclohexyl; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high dual efficacies for human cathepsin S and K and are useful for the treatment of rheumatoid arthritis, osteoarthritis, chronic obstructive pulmonary disease (COPD), atherosclerosis, cardiovascular diseases which exhibit significant damage and remodeling of extracellular matrix (ECM) and chronic pain.

Abstract: A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt, hydrate, complex or pro-drug thereof, wherein: one of R3 and R4 is H, and the other is selected from C1-6-alkyl, C1-6-haloalkyl, C1-6-alkoxy, and C6-12-aralkyl; or R3 and R4 are each independently selected from C1-6-alkyl and halo; R9 is a substituted 5 or 6-membered aryl or heteroaryl group or a 6,5- or 6,6-fused biaryl or heterobiaryl group. Compounds of formula (I) exhibit surprisingly high efficacies for human cathepsin S, excellent selectivity verses other mammalian cathepsins and are useful for treatment of diseases such as rheumatoid arthritis, multiple sclerosis, myasthenia gravis, transplant rejection, diabetes, Sjogrens syndrome, Grave's disease, systemic lupus erythematosis, osteoarthritis, psoriasis, idiopathic thrombocytopenic purpura, allergic rhinitis, asthma, atherosclerosis, obesity, chronic obstructive pulmonary disease and chronic pain.

Abstract: The invention provides compounds of formula I ##STR1## and pharmaceutically acceptable salts thereof; wherein R.sub.50 is hydrogen or C.sub.1-4 alkyl, A.sub.51 is oxygen, sulphur or a group of the formula --NR.sub.52 -- wherein R.sub.52 is hydrogen or C.sub.1-4 alkyl; A.sub.50 comprises i) a mono or bicyclic aromatic ring optionally containing one or more nitrogen, oxygen or sulphur atoms, ii) a cycloalkendiyl group, or iii) an acyclic bridging group having a chain of one, two or three atoms between the cyclobutenedione group and X.sub.50, said chain being a chain of one or two carbon atoms or a chain of one carbon atom and one or more nitrogen, oxygen or sulphur atoms or iv) a bond; X.sub.50 is either a bond or a spacer group providing a chain between A.sub.50 and B.sub.50 of one or two atoms length; B.sub.