FDA Grants Priority Review to Genentech’s Baloxavir Marboxil for the Treatment of Influenza
“The severity of the recent flu season underscores the need for new options beyond currently available treatments, and if approved, baloxavir marboxil would be the first flu medicine with a novel proposed mechanism of action in nearly 20 years,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development. “Baloxavir marboxil has been shown in clinical trials to decrease the duration of symptoms with one dose, and demonstrated a significant reduction in viral shedding in just one day. We look forward to working with the FDA during the review process.”
Baloxavir marboxil is a first-in-class, single-dose investigational oral medicine with a novel proposed mechanism of action designed to target the flu virus, including oseltamivir-resistant strains and avian strains (H7N9, H5N1). Unlike other currently available antiviral treatments, baloxavir marboxil is designed to inhibit the cap-dependent endonuclease protein within the flu virus, which is essential for viral replication.
The NDA is based on results from the Phase III CAPSTONE-1 study of a single dose of baloxavir marboxil compared with placebo or oseltamivir 75 mg, twice daily for five days, in otherwise healthy people with the flu. Additionally, results from a placebo-controlled Phase II study in otherwise healthy people with the flu are included as supporting data in the NDA.
CAPSTONE-1 is a Phase III multicenter, randomized, double-blind, placebo-controlled study that evaluated the efficacy and safety of baloxavir marboxil in 1,436 people in the United States and Japan. The primary endpoint of the study was time to alleviation of symptoms (TTAS), and important secondary endpoints were time to resolution of fever, time to cessation of viral shedding and the proportion of participants positive for influenza virus titer, or virus levels in the body, by time point. The study found the following results:
- Baloxavir marboxil met its primary and secondary endpoints compared to placebo:
- Significantly reduced the duration of flu symptoms by more than one day (median time 53.7 hours versus 80.2 hours; p<0.0001);
- Significantly reduced the duration of fever by nearly a day (median time 24.5 hours versus 42.0 hours; p<0.0001);
- Significantly reduced the length of time viruses continued to be released from the body (median time of viral shedding; 24.0 hours versus 96.0 hours; p<0.0001);
- Significantly reduced the levels of virus in the nose and throat from 24 hours through 120 hours.
- Similar efficacy results were seen between baloxavir marboxil and oseltamivir in relation to duration of symptoms and fever reduction, but significant differences were observed in time to cessation of viral shedding favoring baloxavir marboxil:
- No significant reduction in duration of symptoms (median time 53.5 hours versus 53.8 hours; p=0.7560);
- No significant reduction in time to resolution of fever (median time 24.4 hours versus 24.0 hours; p=0.9225);
- Significantly reduced the length of time the virus continued to be released from the body (viral shedding; 24.0 hours versus 72.0 hours; p<0.0001);
- Significantly reduced the levels of virus in the nose and throat at 24 hours and 72 hours.
Baloxavir marboxil was well-tolerated and had a numerically lower overall incidence of adverse events (20.7 percent) reported compared with placebo (24.6 percent) or oseltamivir (24.8 percent). The most common adverse events reported were diarrhea (3.0 percent), bronchitis (2.6 percent), nausea (1.3 percent) and sinusitis (1.1 percent), and all of these adverse events occurred at a lower frequency than placebo.
About baloxavir marboxil
Baloxavir marboxil is a first-in-class, single-dose investigational oral medicine with a novel proposed mechanism of action designed to target the influenza (“flu”) A and B viruses, including oseltamivir-resistant strains and avian strains (H7N9, H5N1). Unlike other currently available antiviral treatments, baloxavir marboxil is the first in a new class of antivirals designed to inhibit the cap-dependent endonuclease protein within the flu virus, which is essential for viral replication.
Baloxavir marboxil is being studied in an ongoing Phase III development program including pediatric populations with influenza. Data from the global Phase III study (CAPSTONE-2) in people 12 years and older with a high risk of complications from influenza, as defined by the Centers for Disease Control and Prevention (CDC), will be shared at a later date.
Baloxavir marboxil was discovered by Shionogi & Co., Ltd. and is being developed globally by 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 baloxavir marboxil excluding Japan and Taiwan, which will be retained exclusively by Shionogi & Co., Ltd. Baloxavir marboxil was approved in February 2018 by the Japanese Ministry of Health, Labour and Welfare for the treatment of influenza types A and B in adult and pediatric patients, and is being commercialized in Japan and marketed under the brand name XOFLUZA™.
About Genentech in influenza
Influenza, or flu, is one of the most common, yet serious, infectious diseases. Globally, annual epidemics result in 3 to 5 million cases of severe disease, millions of hospitalizations and up to 650,000 deaths worldwide. Although vaccines are an important first line of defense in preventing the flu, there is a need for new medical options for prophylaxis and treatment. Current treatments – including vaccines and antiviral medicines – have limitations as flu viruses are constantly changing and new antiviral medicines are necessary. Genentech is committed to addressing the unmet need in this area through its agreement with Shionogi & Co., Ltd. to develop and commercialize baloxavir marboxil.
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.
Heather Gloe, 650-467-6800
Jocelyn Ashford, 650-866-7579
Loren Kalm, 650-225-3217
Karl Mahler, 011 41 61 687 8503