Ciluprevir
Ciluprevir was a drug used experimentally in the treatment of hepatitis C. It is manufactured by Boehringer Ingelheim and developed under the research code of BILN 2061. It was the first-in-class NS3/4A protease inhibitor to enter clinical development and tested in human. Ciluprevir is a potent competitive reversible inhibitor of NS3/4A protease from HCV genotype 1a and 1b. It shows good selectivity for NS3 protease against representative serine and cysteine proteases, human leukocyte elastase and cathepsin B.
Its development was halted in phase Ib clinical trials because of toxicity in animals. However, ciluprevir scaffold was exploited to design new macrocyclic inhibitors such as simeprevir and danoprevir.