The FDA approved Beyfortus to protect babies from RSV disease

The US Food and Drug Administration (FDA) has approved Sanofi and AstraZeneca’s Beyfortus (nirsevimab-alip) for the prevention of lower respiratory syncytial virus (LRTD) lower respiratory tract disease (RSV) in newborns and infants born during or entering their first RSV season.

The approval also covers children up to 24 months of age who remain susceptible to severe RSV disease during their second RSV season.

The company plans to make Beyfortus, a single-use long-acting antibody, available in the US ahead of the upcoming 2023-2024 RSV season.

RSV is the leading cause of hospitalization for infants under one year of age in the US, averaging 16 times higher than the annual rate for influenza. Each year, an estimated 590,000 cases of RSV disease in infants under one year of age require medical treatment, including a doctor’s office, emergency care, emergency room visits, and hospitalization.

Thomas Triomphe, executive vice president, vaccines, Sanofi, said: “Today’s approval marks an unprecedented moment to protect the health of babies in the US, following the RSV season which takes a heavy toll on babies, their families and the US healthcare system. Beyfortus is the only monoclonal antibody approved for passive immunization to provide safe and effective protection for all infants during their first RSV season. I am proud that, by prioritizing this potential game changer, we will now bring Beyfortus to the American family.”

Beyfortus: opportunities for a paradigm shift in RSV treatment

Iskra Reic, executive vice president, vaccines and immune therapy, AstraZeneca, added: “Beyfortus represents an opportunity for a paradigm shift in preventing serious respiratory disease due to RSV in the large population of infants in the US. The science underlying Beyfortus demonstrates AstraZeneca’s continued leadership in meeting the needs of the most vulnerable populations and reducing the burden on the healthcare system.”

The FDA decision follows positive recommendations from the FDA’s Antimicrobial Drug Advisory Committee and is based on Beyfortus’ extensive clinical development program which includes three critical late-stage clinical trials. Across all clinical endpoints, a single dose of Beyfortus demonstrated high and consistent efficacy against RSV LRTD over five months, the typical RSV season.

Beyfortus is well tolerated with a favorable safety profile consistent across all clinical trials. The overall rate of side effects was comparable between Beyfortus and placebo and most of the side effects were mild or moderate in severity. The most common side effects are rash and injection site reactions.

The Beyfortus single administration was developed to suit the start of the RSV season for babies born before that season or at birth for those born during the RSV season. In clinical trials, Beyfortus helped prevent RSV LRTD requiring medical care in all populations of infants studied, including babies who were born healthy at term, late or preterm, or with certain health conditions that predispose them to severe RSV disease. RSV illnesses that require medical care include a doctor’s office, urgent care, emergency room visits and hospitalization.

Beyfortus, jointly developed by Sanofi and AstraZeneca, was approved in the European Union in October 2022, in the UK in November 2022, and most recently received approval in Canada in April 2023. Regulatory applications are also under review in China, Japan and several other countries.