Lomibuvir is primarily used in the treatment of chronic hepatitis C virus (HCV) infection. It functions as a non-nucleoside polymerase inhibitor, targeting the HCV NS5B RNA-dependent RNA polymerase, which is essential for viral replication. By inhibiting this enzyme, it effectively reduces the viral load in patients. Lomibuvir is often used in combination with other antiviral agents, such as direct-acting antivirals (DAAs), to enhance efficacy and reduce the risk of resistance. This combination therapy has shown promise in achieving sustained virological response (SVR), a key indicator of successful HCV treatment. Its application is particularly significant for patients who have not responded well to previous treatments or those with specific HCV genotypes.