Xofluza Significantly Cuts Influenza Transmission in Phase III Trial

Genentech, a Roche Group member, recently announced promising results from the Phase III CENTERSTONE study, focusing on the antiviral Xofluza® (baloxavir marboxil). The study demonstrated that a single, oral dose of Xofluza significantly reduces the transmission of influenza within households. This marks a significant milestone as it is the first global Phase III study to show that an antiviral used for treating respiratory viral illnesses can reduce virus transmission.

The CENTERSTONE study achieved its primary goal by showing that individuals treated with Xofluza were less likely to spread the flu to household members compared to those who received a placebo. The study also confirmed that Xofluza is well tolerated, with no new safety concerns identified. The research findings will be shared at the 2024 OPTIONS XII for the Control of Influenza Congress in Brisbane, Australia.

Dr. Levi Garraway, Genentech's Chief Medical Officer and Head of Global Product Development, emphasized the importance of this discovery. He noted that these findings could enhance health outcomes not just for individuals but also for communities. The results provide an additional benefit to Xofluza, which is already approved for treating flu symptoms and preventing infection after exposure.

Influenza remains a significant public health concern, causing millions of infections and thousands of deaths annually in the U.S. alone. The co-circulation of multiple respiratory viruses, including COVID-19, further emphasizes the need for effective influenza control measures. Early diagnosis and treatment are crucial for managing both seasonal and pandemic influenza.

The CENTERSTONE study, partially funded by the U.S. Department of Health and Human Services, involved over 4,000 participants across 272 global sites. The study included patients aged five to 64, diagnosed with influenza, and their household contacts. The primary endpoint was the proportion of household contacts who contracted influenza within five days of the index patient being treated. A secondary endpoint evaluated the number of household contacts who developed flu symptoms by Day five.

Xofluza, the antiviral at the center of this study, is a first-in-class, single-dose oral medication that inhibits viral replication by targeting the cap-dependent endonuclease protein. This unique mechanism can potentially reduce both the duration of infectiousness and the severity of the disease. Xofluza has shown efficacy against a range of influenza viruses, including strains resistant to other treatments like oseltamivir.

Approved in over 80 countries, Xofluza is used to treat uncomplicated influenza types A and B. In the U.S., it is approved for treating flu in individuals aged five and older who have been symptomatic for less than 48 hours. Xofluza is also used for post-exposure prophylaxis in the same age group. This approval represents a significant advancement in influenza treatment, marking the first new mechanism of action for an antiviral in nearly two decades.

Discovered by Shionogi & Co., Ltd., Xofluza is being developed and commercialized globally through a collaboration between Roche (which includes Genentech) and Shionogi. Roche holds global rights to Xofluza, excluding Japan and Taiwan, where Shionogi retains exclusive rights.

Genentech, based in South San Francisco, California, has a long history of developing transformative medicines for serious medical conditions. The company remains committed to advancing public health through innovative treatments for infectious diseases like influenza.