Xofluza, also known as baloxavir marboxil, was granted approval to treat acute uncomplicated influenza, also known as flu, in otherwise healthy children aged between five and 12 who have shown symptoms for no more than 48 hours.
The drug was also approved for use by the FDA to prevent influenza in children aged between five years and 12 years who have been in contact with an infected person.
Xofluza is already FDA-approved to treat influenza in people aged 12 and above who have shown symptoms for no more than 48 hours and are otherwise healthy or at high risk of developing influenza-related complications, and in the same age group for those who have been in contact with someone with influenza.
However, the latest move by the FDA marks the first time that the single-dose oral drug has been approved in the United States for children in this age group, Roche said.
While both flu and COVID-19 share many of the same symptoms and can be hard to tell apart initially, most people who get the flu are able to recover on their own within a few days or weeks.
Flu vs COVID
However, it is estimated that there were 29 million flu illnesses in the United States during the 2018-2019 flu season, with 13 million flu-related medical visits, 380,000 flu-related hospitalizations, and 28,000 flu deaths, of which 144 were in children with laboratory-confirmed flu virus infection, according to the CDC.“Despite the ongoing COVID-19 pandemic, influenza continues to be a threat to public health, and effective influenza antivirals remain critical to alleviating the burden on healthcare systems,” said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. “Xofluza has proven to be an important tool in fighting and preventing influenza in adults as well as adolescents, and we are pleased to now offer households and younger children our single-dose oral treatment.”
The FDA approval was based on results from two late-stage studies: miniSTONE-2 and BLOCKSTONE.
The first study, miniSTONE-2, evaluated the use of the single-dose treatment compared with oseltamivir—which is sold under the brand name Tamiflu—in otherwise healthy children. That study included patients aged between five and 12 years of age who were infected with influenza and displayed symptoms such as a high temperature and respiratory issues for no more than 48 hours.
Participants were either given a single dose of Xofluza or oseltamivir twice a day over five days.
“Time to alleviation of influenza signs and symptoms were comparable between Xofluza and oseltamivir,” Roche said.
In those who received Xofluza, it took roughly 138 hours for signs and symptoms of the flue to be alleviated while it took 150 hours in those who received Tamiflu, Roche said.
Xofluza was well tolerated in the study with no new safety signals identified, Roche said.
The second study, BLOCKSTONE, evaluated the single-dose drug compared with a placebo as a preventive treatment for household members (adults and children) who were living with someone with influenza.
In that study, participants were also given a single dose of Xofluza or a placebo as a preventive measure against developing influenza.
“Xofluza showed a statistically significant prophylactic effect on influenza after a single oral dose, by reducing the risk of individuals aged 12 years and above from developing influenza after exposure to an infected household member by 90 percent versus placebo,” Roche said.
Again, Xofluza was well tolerated among participants, Roche said. The study was conducted in Japan by the Japanese pharmaceutical company, Shionogi & Co., Ltd.
Results from both of the studies were published in The Pediatric Infectious Disease Journal and The New England Journal of Medicine, respectively.
Xofluza is already approved in more than 70 countries for the treatment of influenza types A and B.
