Used in the treatment of hepatitis C virus (HCV) infections, this compound functions as a nucleoside inhibitor of the viral RNA-dependent RNA polymerase. It interferes with viral replication by incorporating into the growing RNA chain, causing premature termination. Due to its high potency and barrier to resistance, it has been evaluated in combination therapies with other antiviral agents to improve cure rates in chronic HCV patients. Its application is primarily in oral direct-acting antiviral regimens, offering shorter treatment durations and improved tolerability compared to older interferon-based therapies.