Presatovir is primarily used in the research and development of antiviral therapies, particularly for respiratory syncytial virus (RSV) infections. It functions as an inhibitor of RSV fusion, targeting the virus's ability to enter and infect host cells. This makes it a promising candidate for treating severe RSV infections, especially in high-risk populations such as infants, elderly individuals, and immunocompromised patients. Clinical studies have explored its efficacy in reducing viral load and improving respiratory symptoms. However, its application remains largely experimental, with ongoing research to determine its safety, dosage, and effectiveness in broader patient populations.