Baloxavir susceptibility of seasonal influenza viruses during the first seven seasons of clinical use in Japan, 2017/18 to 2023/24.

ABSTRACT:

Background

Baloxavir marboxil, a cap-dependent endonuclease inhibitor, was approved in Japan in February 2018 for treatment of influenza A and B infections, making Japan the first country to introduce its clinical use.

Aim

We aimed to assess baloxavir susceptibility among seasonal influenza viruses in Japan during the first seven seasons of clinical use, from 2017/18 to 2023/24.

Methods

We conducted nationwide surveillance on 3,671 influenza viruses using phenotypic and genotypic assays to evaluate baloxavir susceptibility and identify amino acid substitutions in the polymerase acidic (PA) protein associated with reduced susceptibility.

Results

Overall, 1.7% of tested viruses exhibited reduced susceptibility to baloxavir. Influenza A(H3N2) viruses showed the hi

SUBMITTER: Takashita E 

PROVIDER: S-EPMC12862291 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature