2′ and 3′-Prodrugs of 1′, 2′, 3′ or 4′-branched β-D or β-L nucleosides, or their pharmaceutically acceptable salts and derivatives are described, which are useful in the prevention and treatment of
Flaviviridae infections and other related conditions. These
modified nucleosides provide superior results against flaviviruses and pestiviruses, including
hepatitis C
virus and viruses generally that replicate through an
RNA dependent
RNA reverse transcriptase. Compounds, compositions, methods and uses are provided for the treatment of
Flaviviridae infection, including HCV infection, that include the administration of an effective amount of the prodrugs of the present invention, or their pharmaceutically acceptable salts or derivatives. These drugs may optionally be administered in combination or alteration with further anti-viral agents to prevent or treat
Flaviviridae infections and other related conditions.