Patent ID: 7824851

Claim:
A method for treating a hepatitis C virus infection in a host, comprising (a) administering an effective amount of a 2′-branched nucleoside of the formula: or a pharmaceutically acceptable prodrug or salt thereof to the host, wherein R 1 and R 2 are independently H; mono, di or triphosphate; acyl; sulfonate ester; benzyl; an amino acid ester; a carbohydrate; a peptide; a cholesterol or a pharmaceutically acceptable leaving group that provides a compound wherein R 1 or R 2 is independently H or phosphate when administered in vivo; R 3 is hydrogen; R 4 is alkyl, alkenyl, or alkynyl; and Base is a pyrimidine; (b) identifying viral resistance to the 2′-branched nucleoside in the host by detecting an amino acid 282 Ser to Thr mutation in the RNA polymerase region of the hepatitis C virus; and (c) administering to the host infected with the virus resistant to the 2′-branched nucleoside, an effective amount of one or more drugs that directly or indirectly induce a mutation in a hepatitis C virus at a location other than nucleotide 8443 (G to C) of the HCV genome or amino acid 282 Ser to Thr of the RNA polymerase region of HCV.