GW-311616, a specific NE inhibitor, may act as a potential targeted drug for leukemia, which may have a profound impact on the future of leukemia-targeted therapy. GW-311616 hydrochloride is a potent, selective, intracellular, orally bioavailable and long duration inhibitor of human neutrophil elastase (HNE) with an IC50 value of 22nM. GW-311616 hydrochloride has been found to be selevtive over other human serine proteases with IC50 values of 22nM for HNE, >100uM for trypsin, cathepsin G, and plasmin, >3uM for chymotrypsin and tissue plasminogen activator. In HNE enzyme kinetic tests, GW-311616 has been reported to inhibit HNE with a Ki value of 0.13nM. In addition, GW-311616 has been revealed to inhibit HWB with an IC50 values of 0.67uM in HWB assay. Moreover, by measurement of intraneutrophil elastase activity, GW-311616 hydrochloride has been suggested to have a dose-response and duration of action in blood samples of dog. At present, although research on GW-311616 has being dropped at the preclinical stage, the beneficial profile of oral GW-311616 may make it usuful in the design of new drugs.