Compounds of the formula II, wherein R3 is C1-C3 alkyl or C3-C6 cycloalkyl, either of which is optionally substituted with one or two methyl and/or a fluoro, trifluoromethyl or methoxy, when R3 is C3-C6 cycloalkyl it may alternatively be gem substituted with fluoro； R4 is methyl or fluoro； m is 0, 1 or 2； E is a bond, or thiazolyl, optionally substituted with methyl or fluoro； A1 is CH or N, A2 is CR6R7 or NR6, provided at least one of A1 and A2 comprises N； n is 0 or 1 such that the ring containing A1 and A2 is a saturated, nitrogen-containing ring of 5 or 6 ring atoms； R6 is H, C1-C4 alkyl, C1-C4 haloalkyl, C1-C3 alkyl-O-C1-C3 alkyl, or when A2 is C, R6 can also be C1-C4 alkoxy or F； R7 is H, C1-C4 alkyl or F； or a pharmaceutically acceptable salt, N-oxide or hydrate thereof, have utility in the treatment of disorders characterized by inappropriate expression or activation of cathepsin K, such as osteoporosis, osteoarthritis, rheumatoid arthritis or bone metastases.
