Stop Viral Replication Across a Broad Range of Flu Strains 1

Active even against key oseltamivir-resistant and avian strains of the flu*

Influenza A and B viruses with treatment-emergent amino acid substitutions at positions associated with reduced susceptibility to baloxavir in cell culture were observed in clinical studies. The most common substitution emerging during baloxavir treatment is PA-I38X. 1,11,12

Consider available information on influenza virus types or subtypes and on drug susceptibility patterns for circulating influenza virus strains when deciding whether to prescribe XOFLUZA.

*Antiviral activity was determined against laboratory strains and clinical isolates in vitro. The relationship between antiviral activity in cell culture and clinical response to treatment in humans has not been established. 1


Single-Dose XOFLUZA Interrupts the Flu Viral Life Cycle Early, Helping Prevent Replication 1,13

First-in-its-class XOFLUZA has a proposed mechanism of action (MOA) that works differently to stop the flu at its source 1,15

  1. Flu virus enters the host cell and uncoats 13,14,16
    • M2 ion channel blockers/adamantanes target viral uncoating; however, they are no longer recommended by the CDC due to high resistance*
  2. Flu virus replicates 1,13,15
    • The novel MOA of single-dose XOFLUZA works by inhibiting polymerase acidic (PA) endonucleases to prevent viral replication
    • The flu virus uses the replication machinery of the host cell
    • Once inside the host cell, XOFLUZA inhibits the PA endonuclease of the flu virus by cleaving the 5’ end (cap) of the host cell pre-mRNA, which is then used as a primer to initiate transcription of viral RNA
    • Without the ability to start the replication process, the virus cannot continue to clone itself and spread throughout the body 
  3. Viral assembly, budding, and release from host cell 13,17
    • Neuraminidase inhibitors, such as oseltamivir, target viral release, which prevents the already-replicated viruses from leaving the host cell

*Source: Centers for Disease Control and Prevention (CDC). The CDC does not endorse private products, services, or enterprises. The content provided is for informational purposes only. Find the latest at

ER = endoplasmic reticulum.

XOFLUZA® (baloxavir marboxil) Single Dose Icon

Treatment in a Single Dose

Keep it simple with a full course of treatment in a single dose. 1