Presatovir is a novel inhibitor of respiratory syncytial virus (RSV) fusion F protein patented by Gilead Sciences, Inc. as an antiviral agent. Upon oral administration of GS-5806, this agent specifically binds to F protein on the viral surface, which inhibits RSV F protein-mediated fusion with the host cell membrane and prevents viral entry. This blocks RSV replication, reduces viral load, and decreases the severity of the disease. Presatovir exhibited potent antiviral activity against 75 RSV clinical isolates from both A and B subgroups in vitro. In vivo, presatovir demonstrated efficient penetration into the lung and epithelial lining fluid in Sprague‐Dawley rats and in dogs and cattle. Presatovir demonstrated dose‐dependent antiviral activity in both the upper respiratory tract and the lungs in a nonclinical study of RSV‐infected cotton rats as well as in a clinical study of healthy adults experimentally infected with RSV.