Relacatib (SB-462795) is a novel, potent, and orally active inhibitor of human cathepsins K, L, and V. It exhibits high affinity for these enzymes, with Ki values of 41 pM, 68 pM, and 53 pM, respectively. Moreover, Relacatib effectively inhibits endogenous cathepsin K in situ in human osteoclasts, as well as human osteoclast-mediated bone resorption, with IC 50 values of 45 nM and 70 nM, respectively. Additionally, in vitro studies demonstrate Relacatib's inhibitory effect on bone resorption in human tissue, while in vivo studies on cynomolgus monkeys further validate its efficacy in reducing bone resorption.
Thiocarbazate, also known as CID16725315, is an inhibitor of human cathepsin L. Inhibition of cathepsin L thus holds promise for therapeutic intervention for both SARS-CoV and Ebola virus infection. With respect to the development of antiviral agents, inhibitors of human cathepsin L are not subject to resistance because of rapid mutations of the viral genome. Cathepsin L is therefore an attractive target for drug development.
Oxocarbazate, also known as CID23631927, is an inhibitor of human cathepsin L. In the cathepsin L inhibition assay, The oxocarbazate caused a time-dependent 17-fold drop in IC50 from 6.9 nM (no preincubation) to 0.4 nM (4-h preincubation). Slowly reversible inhibition was demonstrated in a dilution assay. CID23631927 demonstrate activity in blocking both SARS-CoV (IC50 = 273 nM) and Ebola virus (IC50 = 193 nM) entry into human embryonic. CID 23631927 was a subnanomolar, slow-binding, reversible inhibitor of human cathepsin L that blocked SARS-CoV and Ebola pseudotype virus entry in human cells. Inhibition of cathepsin L thus holds promise for therapeutic intervention for both SARS-CoV and Ebola virus infection.