BLOCKSTONE study reaches primary endpoint of fewer people testing positive for the flu, with fever and at least one respiratory symptom, when treated with Xofluza versus placebo
Xofluza may represent an important and convenient treatment for both reducing the burden of seasonal flu and limiting the impact of a pandemic
South San Francisco, CA -- September 1, 2019 --
Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), today announced that the Phase III BLOCKSTONE study showed preventive treatment with XofluzaTM (baloxavir marboxil) after exposure to an infected household member significantly reduced the risk of people developing the flu by 86 percent versus placebo. The results show just 1.9 percent of Xofluza-treated household members had the flu compared with 13.6 percent in the placebo-treated group (p<0.0001). This benefit with Xofluza remained statistically significant versus placebo regardless of influenza A subtype (H1N1: 1.1 percent versus 10.6 percent, p=0.0023; H3: 2.8 percent versus 17.5 percent, p<0.0001). It was also observed in household contacts who are at high risk of flu-associated complications (2.2 percent versus 15.4 percent, p=0.0435), and children under 12 years of age (4.2 percent versus 15.5 percent, p=0.0339), who are more vulnerable to developing the flu. Xofluza had a comparable safety profile to placebo, with an overall incidence of adverse events being 22.2 percent for Xofluza and 20.5 percent for placebo. No serious adverse events were reported for Xofluza. 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 (Abstract #11718).
“As the influenza virus can rapidly infect those around us, limiting the spread of infection within households potentially avoids a significant impact on the wider community – a critical step in the global fight against the flu,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development. “We are encouraged by the BLOCKSTONE study, the first to show that Xofluza is an effective preventive treatment following exposure to the flu and we look forward to sharing these data with health authorities.”
The BLOCKSTONE study also demonstrated that even when fewer criteria were applied (proportion of participants with the flu, with fever or one or more respiratory symptoms), there was still a significant 76 percent reduction in the risk of household members developing the flu with Xofluza versus placebo (5.3 percent versus 22.4 percent respectively, p<0.0001).
Xofluza is the first and only one-dose oral medicine approved to treat the flu in otherwise-healthy patients, and the first flu medicine with a novel proposed mechanism of action approved by the FDA in nearly 20 years. Robust clinical evidence has demonstrated the benefit of Xofluza in several populations (otherwise-healthy, high-risk, children) and treatment settings (symptomatic flu, post-exposure prophylaxis).
BLOCKSTONE is a Phase III, randomized, post-exposure prophylaxis study that evaluated a single dose of Xofluza compared with placebo as a preventive treatment for household members (adults and children) who are living with someone with an influenza infection confirmed by a rapid influenza diagnostic test (the ‘index patient’). The study was conducted by Shionogi & Co., Ltd. during the 2018-2019 flu season in Japan.
Participants enrolled in the study were household members of someone who had been diagnosed with influenza. The participants were randomized to receive a single dose of Xofluza (dose according to body weight) or placebo as a preventive measure against developing influenza. The primary endpoint of the study was to evaluate the proportion of participants who tested positive for the influenza virus and had fever, and one or more respiratory symptoms between day one and ten. Secondary endpoints were clinical efficacy, pharmacokinetics and safety and tolerability.
About Xofluza ™ (baloxavir marboxil)
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.
Xofluza is being further studied in a Phase III development program, including children under the age of one (NCT03653364), severely ill, hospitalized people with the flu (NCT03684044), as well as to assess the potential to reduce transmission of the flu from an infected person to healthy people (NCT03969212).
Xofluza was discovered by Shionogi & Co., Ltd. and is being further developed and commercialized globally in collaboration with the Roche Group (which includes Genentech in the U.S.) and Shionogi & Co., Ltd. Under the terms of this agreement, Roche holds worldwide rights to Xofluza excluding Japan and Taiwan, which will be retained exclusively by Shionogi & Co., Ltd.
XOFLUZA U.S. Indication
XOFLUZA is a prescription medicine used to treat the flu (influenza) in people 12 years of age and older who are otherwise healthy, or at high risk of developing influenza-related complications, who have had flu symptoms for no more than 48 hours.
It is not known if XOFLUZA is safe and effective in children younger than 12 years of age or weighing less than 88 pounds (40 kg).
Limitations of Use : Influenza viruses change over time, and factors such as the virus type or subtype, emergence of resistance or changes in viral virulence could diminish the clinical benefit of antiviral drugs. Consider available information on drug susceptibility patterns for circulating influenza virus strains when deciding whether to use XOFLUZA.
Important Safety Information
Do not take XOFLUZA if you are allergic to baloxavir marboxil or any of the ingredients in XOFLUZA.
Before you take XOFLUZA, tell your healthcare provider about all of your medical conditions, including if you :
- are pregnant or plan to become pregnant. It is not known if XOFLUZA can harm your unborn baby.
- are breastfeeding or plan to breastfeed. It is not known if XOFLUZA passes into your breast milk.
Tell your healthcare provider about all the medicines you take , including prescription and over-the-counter medicines, vitamins and herbal supplements.
Talk to your healthcare provider before you receive a live flu vaccine after taking XOFLUZA.
Take XOFLUZA with or without food. Do not take XOFLUZA with dairy products, calcium-fortified beverages, laxatives, antacids or oral supplements containing iron, zinc, selenium, calcium or magnesium.
The most common side effects are diarrhea, bronchitis, nausea, common cold symptoms (nasopharyngitis) and headache.
XOFLUZA is not effective in treating infections other than influenza. Other kinds of infections can have symptoms like those of the flu or occur along with the flu and may need different kinds of treatment. Tell your healthcare provider if you feel worse or develop new symptoms during or after treatment with XOFLUZA or if your flu symptoms do not start to get better.