Background:

Ki: 0.185 nM

Cathepsin S is a lysosomal cysteine protease, playing an important role in antigen presentation. The inhibition of Cathepsin S is expected to result in immunosuppression, which makes this enzyme an attractive target to potentially treat autoimmune and inflammatory diseases. Cathepsin S inhibitor is a novel Cathepsin S inhibitor.

In vitro: Cathepsin S inhibitor was a slow, tight-binding reversible inhibitor of recombinant cathepsin S, exhibiting greater selectivity for cathepsin S compared to cathepsin B [1].

In vivo: No animal in vivo data available currently

Clinical trial: Oral Cathepsin S inhibitor that blocked MHCII antigen presentation could result in a T-cell-selective immunosuppressant agent with improved safety over the current standard of care for the treatment of rheumatoid arthritis, psoriasis, multiple sclerosis and other autoimmune-based inflammatory diseases [2].

参考文献:
[1] Wiener JJ, Sun S, Thurmond RL.  Recent advances in the design of cathepsin S inhibitors. Curr Top Med Chem. 2010;10(7):717-32.
[2] Lee-Dutra A, Wiener DK, Sun S.  Cathepsin S inhibitors: 2004-2010. Expert Opin Ther Pat. 2011;21(3):311-37.