Roche's Xofluza (baloxavir marboxil) has demonstrated a significant reduction in the transmission of influenza viruses within households, according to topline results from the Phase III CENTERSTONE study. This randomized, placebo-controlled trial, conducted across 272 sites worldwide with over 4,000 participants, evaluated the efficacy of a single oral dose of Xofluza in curbing the spread of flu among household contacts.
Study Design and Endpoints
The study included patients aged 5 to 64 years diagnosed with influenza (index patients) and their household contacts. The primary endpoint was the proportion of household contacts who contracted influenza within five days post-treatment with Xofluza or placebo. Secondary endpoints included the proportion of household contacts who tested positive for influenza by day five and also developed symptoms.
Key Findings
The trial met its primary endpoint, demonstrating that a single dose of Xofluza taken by index patients significantly reduced the likelihood of household members contracting the virus. The antiviral treatment was also found to be well-tolerated, with no new safety signals identified.
Levi Garraway, Roche's chief medical officer and head of global product development, stated, "Building on Xofluza’s established efficacy in treating and preventing influenza after exposure, this new evidence of transmission reduction represents an important advance that could help improve health outcomes at an individual and community level. We look forward to discussing these data with regulatory authorities and public health organizations for influenza pandemic preparedness to bring these benefits to patients."
Xofluza's Mechanism of Action
Xofluza is a single-dose oral medicine designed to block viral replication by inhibiting the cap-dependent endonuclease protein, potentially reducing the duration of infectiousness and disease. It is approved in over 80 countries for treating uncomplicated influenza types A and B and as a preventative treatment (post-exposure prophylaxis) in Europe.
Implications for Influenza Management
Influenza remains a significant public health burden, with seasonal epidemics resulting in an estimated one billion cases, millions of hospitalizations, and up to 650,000 deaths globally each year. The emergence of multiple respiratory viruses, including COVID-19, underscores the importance of effective influenza control measures. Xofluza's ability to reduce transmission could play a crucial role in mitigating the spread of influenza, especially in household settings where transmission rates are high.
The CENTERSTONE study was partially supported by federal funds from the US Department of Health and Human Services. Full data from the study will be presented at the 2024 OPTIONS XII for the Control of Influenza congress in Brisbane, Australia.
