Patent ID: 7576057

Claim:
A method of treating or preventing hepatitis C virus infection in a subject, the method comprising administering to the subject a therapeutically effective amount of a cyclosporine derivative of formula (I): wherein: A represents (E) —CH═CHCH 2 R, wherein R represents hydrogen, —SH, thioalkyl, or carboxyl; B represents methyl or ethyl; R 1 represents: straight- or branched-chain alkyl containing from one to six carbon atoms, substituted by one or more groups R 3 which may be the same or different; straight- or branched-chain alkenyl or alkynyl containing from two to six carbon atoms substituted by one or more groups R 3 which may be the same or different; or cycloalkyl containing from three to six carbon atoms optionally substituted by one or more groups R 3 which may be the same or different; R 2 represents isobutyl or 2-hydroxyisobutyl; R 3 is selected from the group consisting of —NR 4 R 5 , —C(═O)NR 4 R 5 and —C(═NR 6 )NR 4 R 5 ; R 4 and R 5 , which may be the same or different, each represent: hydrogen; straight- or branched-chain alkyl containing from one to six carbon atoms; straight- or branched-chain alkenyl or alkynyl containing from two to four carbon atoms; or cycloalkyl containing from three to six carbon atoms optionally substituted by straight- or branched-chain alkyl containing from one to six carbon atoms; or R 4 and R 5 , together with the nitrogen atom to which they are attached, form a saturated or unsaturated heterocyclic ring containing from four to six ring atoms, which ring may optionally contain another heteroatom selected from the group consisting of nitrogen, oxygen and sulfur and may be optionally substituted by from one to four groups which may be the same or different selected from the group consisting of alkyl, phenyl and benzyl; R 6 represents hydrogen, straight- or branched-chain alkyl containing from one to six carbon atoms, cyano, alkylsulfonyl, sulfonamide, or nitro; or a pharmaceutically acceptable salt thereof; with the proviso that when A is (E)—CH═CHCH 3 and B is ethyl, then R 1 is not L—CH 2 CH 2 CH 2 NH 2 .