NCIt definition : The hydrochloride salt form of sisunatovir, 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.;