Hepatitis C virus (HCV) infection is a leading cause of liver diseases such as cirrhosis and hepatocellular carcinoma. There are estimated 170 million people worldwide chronically infected with the virus. The lack of highly effective and safe therapeutics for HCV infection has spurred intensive efforts to develop anti-HCV drugs as evidenced by the large number of new patent applications filed each year. Nucleoside and nucleotide inhibitors are the analogues of DNA or RNA substrates, and they inhibit viral polymerases by acting as chain terminators, viral mutagens, or simple competitive inhibitors. The successful development of various nucleoside and nucleotide inhibitors for the treatment of HIV and HBV infections has prompted the drug industry to seek similar strategies for HCV. This review summarizes recently issued or published patents covering nucleoside and nucleotide inhibitors for HCV. The claimed chemical structures and available biological activities, mechanism of action, and drug resistance profiles are discussed. The development status of several promising nucleoside inhibitors is also described.
Keywords: Hepatitis C virus, HCV, NS5B RNA-dependent RNA polymerase, polymerase inhibitor, nucleoside analogue, nucleotide analogue, patent, chain terminator, 2'-methyl nucleoside