Odalasvir is primarily used in the treatment of chronic hepatitis C virus (HCV) infection. It functions as an NS5A inhibitor, targeting a specific protein essential for viral replication. This makes it effective in reducing viral load and improving liver function. Odalasvir is often administered in combination with other antiviral agents, such as sofosbuvir, to enhance its efficacy and prevent the development of drug resistance. Its use is particularly significant for patients with genotypes of HCV that are difficult to treat with other therapies. The drug has shown promise in clinical trials for achieving sustained virologic response, which is a key indicator of successful HCV treatment.