Baloxavir marboxil as a new specific anti-influenza drug

Baloxavir marboxil is the first antiviral drug with a unique single dose, registered in Russia in September 2020 under the trade name Xoflusa, for treating infection caused by influenza A and B viruses. This article presents an overview of studies on the anti-influenza activity of baloxavir marboxil by foreign colleagues. Data from scientific articles by different authors were analyzed and in vitro results and clinical data were considered, which can help in making recommendations for the use of the drug for the treatment and postexposure prophylaxis of influenza. Baloxavir marboxil acts as a selective low-molecular-weight inhibitor of an enzyme specific to the influenza virus in the viral RNA polymerase complex and is effective against strains resistant to oseltamivir. In the combined phenotypic analysis and analysis based on the sequence in the polymerase acidic (PA) protein, the frequency of viruses showing reduced susceptibility to the drug remains low. Numerous studies have demonstrated the safety profile and productivity of influenza treatment in various groups (without risk factors and high-risk patients). Baloxavir marboxil stops the replication of the influenza virus in the early stages, which terminates its release during the first day and significantly relieves the patients condition on the second day. Monitoring of the antiviral activity of the drug, especially in children aged 12 years and people with weakened immunity, should be closely monitored to develop clinical recommendations and prevent the formation of substitutions I38(T/F/M/S/L/V) in the PA of influenza A and B viruses that reduce their sensitivity to the drug.