Definition

An orally available, small molecule inhibitor of human respiratory syncytial virus (RSV) fusion protein (F protein), with potential antiviral activity. Upon oral administration, sisunatovir specifically targets and binds to RSV-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. RSV-F protein, a viral surface glycoprotein, plays a key role in RSV fusion with and entry into target cells.