One-dose Baloxavir shows promising results in children with flu in clinical trial

One-dose Baloxavir shows promising results in children with flu in clinical trial.

Baloxavir, developed in Japan, is the newest novel flu treatment since oseltamivir and zanamivir and was approved by the US Food and Drug Administration (FDA) in October 2018 for use in patients ages 12 years and older.

Genentech today announced that one-dose Xofluza™ (baloxavir marboxil) was a well-tolerated and effective potential treatment for the flu in otherwise healthy children aged one to less than 12 years old. The study met its primary endpoint, which evaluated the proportion of patients with adverse events (AEs) or severe AEs up to study day 29, demonstrating results consistent with the safety profile of Xofluza. In Xofluza-treated participants, 46.1 percent experienced at least one treatment-emergent AE compared to 53.4 percent in the oseltamivir arm. The study also showed the efficacy of Xofluza to be comparable to oseltamivir (a proven effective treatment for children with the flu). In addition, consistent with data in adults and adolescents, Xofluza reduced the length of time that the flu virus continued to be released from the body by more than two days compared with oseltamivir (viral shedding; median time of 24.2 hours versus 75.8 hours, respectively). Full results of the study were presented as a late-breaking abstract during the OPTIONS X 2019 congress in Singapore on Sunday, September 1, 2019.

Xofluza is a first-in-class, one-dose oral medicine with a novel proposed mechanism of action that has demonstrated efficacy in a wide range of influenza viruses, including in vitro activity against oseltamivir-resistant strains and avian strains (H7N9, H5N1) in non-clinical studies. Unlike other currently available antiviral treatments, Xofluza is the first in a new class of antivirals designed to inhibit the cap-dependent endonuclease protein, which is essential for viral replication.

Xofluza is currently approved in several countries for the treatment of influenza types A and B in children, adolescents and adults, and in the United States (U.S.) for the treatment of acute, uncomplicated influenza in people 12 years of age and older. In addition, a supplemental New Drug Application (sNDA) for Xofluza as a one-dose oral treatment for people at high risk of complications from the flu is under review by the FDA and a decision is expected by November 4, 2019.

“Each year approximately one in three children develop the flu, and their less mature immune systems mean they are slower to fight the infection and more vulnerable to complications,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development. “We are committed to developing new, more convenient treatment options for children with the flu and look forward to sharing these data with global health authorities.”

MINISTONE-2 is the first global Phase III study for Xofluza in children. It showed that Xofluza was comparable to oseltamivir in relation to key secondary endpoints, including the time to alleviation of influenza signs and symptoms (median 138.1 hours versus 150.0 hours).

This is the fourth positive Phase III study for Xofluza, which has now demonstrated benefit in several populations (otherwise healthy, high-risk, children) and treatment settings (symptomatic, post-exposure prophylaxis). Xofluza is being further studied in an ongoing Phase III development program, including children under one year, severely ill hospitalized people with the flu, and to assess the potential to reduce transmission of the flu from an infected person to healthy people.