Genentech Announces FDA Approval of Xofluza for the Prevention of Influenza Following Contact With an Infected Person

“With today’s approval, Xofluza is now available as the first single-dose, post-exposure preventive treatment for influenza,” said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. “We’re hopeful that reducing the burden of influenza may help to mitigate the strain on our healthcare system amid the COVID-19 pandemic.”

Post-exposure prophylaxis with single-dose Xofluza was evaluated in the Phase III BLOCKSTONE study, which was recently published in The New England Journal of Medicine. BLOCKSTONE evaluated Xofluza compared with placebo as a preventive treatment for household members (adults and children) who were living with someone with influenza. Xofluza showed a statistically significant prophylactic effect on influenza after a single oral dose in people exposed to an infected household contact. The proportion of household members 12 years of age and older who developed influenza was 1% in participants treated with Xofluza and 13% in the placebo-treated group. Xofluza was well tolerated in this study and no new safety signals were identified.

“The flu is a serious illness that burdens households and sickens millions across the U.S. every year,” said Serese Marotta, Chief Operating Officer at Families Fighting Flu. “As we are about to enter a flu season within a global COVID-19 pandemic, we welcome Xofluza as a single-dose flu medicine to be used preventively after exposure to flu.”

The most frequently reported adverse events (occurring in at least 1% of adult and adolescent influenza patients treated with Xofluza) included diarrhea (3%), bronchitis (3%), nausea (2%), sinusitis (2%), and headache (1%).

Additionally, Genentech is determining a path forward with the FDA for a potential indication for Xofluza as a treatment for acute uncomplicated influenza in otherwise healthy children (one to 12 years of age) and for the prevention of influenza in the same age group who have been exposed to influenza. Xofluza is currently not approved for use in this population.

Xofluza is already FDA-approved to treat acute uncomplicated influenza in people 12 years of age and older who have had influenza symptoms for no more than 48 hours and who are otherwise healthy or at high risk of developing influenza-related complications. Although some of the symptoms of COVID-19 and influenza can look similar, the two illnesses are caused by completely different viruses. Xofluza is specifically designed to treat influenza viruses only and is not effective against SARS-CoV-2, the coronavirus causing COVID-19.

About BLOCKSTONE

BLOCKSTONE is a Phase III, double-blind, multicenter, randomized, placebo-controlled, post-exposure prophylaxis study that evaluated a single dose of Xofluza compared with placebo in household members (adults and children) who were living with someone with influenza confirmed by a rapid influenza diagnostic test (the ‘index patient’). The study was conducted by Shionogi & Co., Ltd. in Japan during the 2018-2019 influenza season.

Those diagnosed with influenza were required to have onset of symptoms for less than 48 hours and participants were required to have lived with those diagnosed for more than 48 hours. 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.

About Xofluza^® (baloxavir marboxil)

Xofluza is a first-in-class, single-dose oral medicine with an innovative 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. Xofluza is the first in a class of antivirals designed to inhibit the cap-dependent endonuclease protein, which is essential for viral replication.

Xofluza is available in the U.S. and in several other countries for the treatment of influenza types A and B. In the U.S., Xofluza is approved for the treatment of acute, uncomplicated influenza in people 12 years of age and older who are otherwise healthy or at high risk of developing serious complications from influenza, and who have been symptomatic for no more than 48 hours. Xofluza is also approved for post-exposure prophylaxis of influenza in people 12 years of age and older following contact with an individual who has influenza. Xofluza was the first new antiviral to be approved by the FDA in 20 years.

Robust clinical evidence has demonstrated the benefit of Xofluza in several populations (otherwise-healthy, high-risk and post-exposure prophylaxis). Xofluza is being further studied in a Phase III development program, including children under the age of one (NCT03653364) as well as to assess the potential to reduce transmission of influenza 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 have had flu symptoms for no more than 48 hours.
• Prevent the flu in people 12 years of age and older following contact with a person who has the flu.

It is not known if XOFLUZA is safe and effective in children less than 12 years of age.

Important Safety Information

Do not take XOFLUZA if you are allergic to baloxavir marboxil or any of the ingredients in 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.
  • Breastfeeding or plan to breastfeed. It is not known if XOFLUZA passes into your breast milk.
• Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, antacids, laxatives, vitamins, and herbal supplements.

Serious side effects may include

• Allergic reaction. Get emergency medical help right away if you develop any of the following signs or symptoms of an allergic reaction:
  • trouble breathing
  • skin rash, hives or blisters
  • swelling of your face, throat or mouth
  • dizziness or lightheadedness

The most common side effects of XOFLUZA in clinical studies were diarrhea, bronchitis, nausea, sinusitis, and headache. These are not all the possible side effects of XOFLUZA. Call your healthcare provider for medical advice about side effects.

XOFLUZA is not effective in treating or preventing infections other than influenza. Other kinds of infections can have symptoms like those of the flu or occur along with flu and may need different kinds of treatment. XOFLUZA does not prevent bacterial infections that may happen with the flu. 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.

You are encouraged to report side effects to Genentech by calling 1-888-835-2555 or to the FDA by visiting www.fda.gov/medwatch or calling 1-800-FDA-1088.

Please see full Prescribing Information, including Patient Product Information.

About Genentech in Influenza

Influenza is one of the most common, yet serious, infectious diseases, representing a significant threat to public health. Since 2010, the Centers for Disease Control and Prevention (CDC) estimates that influenza has resulted annually in 9 to 45 million illnesses, 140,000 to 810,000 hospitalizations and 12,000 to 61,000 deaths annually. Although vaccines are an important first line of defense in preventing influenza, there is a need for new medical options for prophylaxis and treatment. Genentech is committed to addressing the unmet need in this area through its agreement with Shionogi & Co., Ltd. to develop and commercialize Xofluza.

About Genentech

Founded more than 40 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.

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