A promising new drug called baloxavir marboxil (Xofluza) developed in Japan has been shown to stop the flu virus from spreading 24 hours after intake.

The drug interferes with influenza A and influenza B's main replication process instead of inhibiting the neuraminidase enzyme, as accomplished by previous drugs such as oseltamivir (Tamiflu) and zanamivir (Relenza). As shown in the illustration, viral neuraminidase sits on the surface of influenza viruses and enables it to be released once reproduced within the infected host cell.

Xofluza accomplishes its mode of action by inhibiting the cap-dependent endonuclease activity of the viral polymerase. It achieves this by inhibiting the process known as cap snatching, which is a mechanism expl ...