Baloxavir marboxil (Genentech), an investigational, single-dose, oral treatment for acute uncomplicated influenza in those aged ≥12 years has been granted Priority Review by the Food and Drug Administration (FDA). 

Baloxavir marboxil is a first-in-class, single-dose oral medicine with a novel mechanism of action designed to target influenza A and B viruses, including oseltamivir-resistant strains and avian strains (H7N9, H5N1). Unique to the treatment is its ability to inhibit the cap-dependent endonuclease protein within the flu virus, which is needed for viral replication.

The New Drug Application for baloxavir marboxil is supported by results from the Phase 3 CAPSTONE-1 study (N=1436) which examined the effects of a single dose of baloxavir marboxil vs placebo or oseltamivir 75mg twice daily for 5 days. 

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Results showed a significant reduction in duration of flu symptoms with baloxavir marboxil vs placebo (median time 53.7 hours vs 80.2 hours [P<0.0001]; respectively). Compared with placebo, treatment with baloxavir marboxil significantly reduced the duration of fever, viral shedding, and levels of virus in the nose and throat. 

When compared with oseltamivir, there were no significant differences seen with baloxavir marboxil with regard to reduction in flu symptom duration or time to fever resolution (median time 53.5 hours vs 53.8 hours [P=.7560] and median time 24.4 hours vs 24 hours [P=.9225], respectively). Treatment with baloxavir marboxil did significantly reduce the length of time of viral shedding (24 hours vs 72 hours, P<0.0001) and significantly reduced the levels of virus in the nose and throat at 24 hours and 72 hours. 

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The most common adverse events reported with baloxavir marboxil were diarrhea (3.0%), bronchitis (2.6%), nausea (1.3%) and sinusitis (1.1%),

The Company stated that they expect the FDA to make a decision on approval by December 24, 2018. 

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This article originally appeared on MPR