Baloxavir marboxil for uncomplicated influenza in adults and adolescents

Findings from two randomized controlled trials indicate that single-dose oral baloxavir, a selective inhibitor of influenza cap-dependent endonuclease, did not have any apparent safety concerns and was also linked to clinical benefit and antiviral activity in individuals with acute uncomplicated influenza.

Findings from two randomized controlled trials indicate that single-dose oral baloxavir, a selective inhibitor of influenza cap-dependent endonuclease, did not have any apparent safety concerns and was also linked to clinical benefit and antiviral activity in individuals with acute uncomplicated influenza. Results from the Phase II trial show that the median time to alleviation of influenza symptoms was up to 28.2 hours shorter in the baloxavir groups compared with the placebo group. In the Phase III trial, meanwhile, the median time to alleviation of symptoms was 53.7 hours with baloxavir, versus 80.2 hours with placebo. While the time to alleviation of symptoms was similar with baloxavir and oseltamivir, there were greater reductions in viral load 1 days after initiating baloxavir compared with placebo or oseltamivir. Adverse events were reported in 24.6% of the placebo group, 24.8% of the oseltamivir group, and 20.7% of the baloxavir group. The researchers also noted some evidence for the decreased susceptibility to baloxavir after treatment, occurring in 2.2% and 9.7% of baloxavir recipients in the phase II trial and phase III trial, respectively. In conclusion, they wrote: "Because this treatment is inhibitory for influenza virus strains resistant to neuraminidase inhibitors or M2 ion-channel inhibitors, it could provide an option for patients with infections caused by such viruses."