Used in antiviral therapies, particularly in the treatment of hepatitis C. It acts as a nucleoside inhibitor, interfering with viral RNA replication by targeting the RNA-dependent RNA polymerase enzyme. This compound serves as a key intermediate in the synthesis of direct-acting antiviral agents, contributing to highly effective, well-tolerated treatment regimens. Its structure allows integration into viral RNA chains, leading to premature termination of replication. Widely utilized in pharmaceutical development for improved potency and resistance profiles in HCV drug combinations.