ciluprevir 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 (ki = 0.3 nm) and 1b (ki = 0.66 nm). it shows good selectivity for ns3 protease against representative serine and cysteine proteases, human leukocyte elastase and cathepsin b (ic50 > 30 μm). ciluprevirclinical dataroutes ofadministrationby mouthatc codenonelegal statuslegal status development terminated pharmacokinetic dataprotein binding>99.1%identifiers iupac name (2r,6s,12z,13as,14ar,16as)-6--2-(oxy)-5,16-dioxo-1,2,3,6,7,8,9,10,11,13a,14,15,16,16a-tetradecahydrocyclopropapyrrolo diazacyclopentadecine-14a(5h)-carboxylic acid cas number300832-84-2pubchem cid9853710chemspider8029420unii75c8du40t0chemblchembl297884chemical and physical dataformulac40h50n6o8smolar mass774.93 g·mol−13d model (jsmol) smiles o=c2n7(c(=o)o)c7/c=c\ccccc(nc(=o)oc1cccc1)c(=o)n62c(oc3cc(nc4c3ccc(oc)c4)c5nc(sc5)nc(c)c)c6 inchi inchi=1s/c40h50n6o8s/c1-23(2)41-38-43-32(22-55-38)31-19-34(28-16-15-26(52-3)17-30(28)42-31)53-27-18-33-35(47)45-40(37(49)50)20-24(40)11-7-5-4-6-8-14-29(36(48)46(33)21-27)44-39(51)54-25-12-9-10-13-25/h7,11,15-17,19,22-25,27,29,33h,4-6,8-10,12-14,18,20-21h2,1-3h3,(h,41,43)(h,44,51)(h,45,47)(h,49,50)/b11-7-/t24-,27-,29+,33+,40-/m1/s1key:pjzpdfuuxkkdnb-kninvfkusa-n 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 (tmc-435) and danoprevir.