New RSV Monoclonal Antibody Approved to Protect All Infants

AstraZeneca and Sanofi's today announced Beyfortus™ (nirsevimab-alip) has been approved in the United States for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD) in newborns and infants born during or entering their first RSV season.

And for children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. 

Beyfortus is the first preventive option approved to protect a broad infant population, including those born healthy at term or preterm or with specific health conditions that make them vulnerable to severe RSV disease.

Furthermore, the single dose can be flexibly administered at the beginning of the RSV season or at birth for those born during the RSV season.

The companies confirmed on July 17, 2023, Beyfortus will be available for the 2023-2024 RSV season in the U.S.

Iskra Reic, Executive Vice President, Vaccines and Immune Therapies, AstraZeneca, said in a press release, "Beyfortus represents an opportunity for a paradigm shift in preventing serious respiratory disease due to RSV across a broad infant population in the U.S."

"The science that Beyfortus is built on demonstrates AstraZeneca's continued leadership in addressing the needs of the most vulnerable populations and reducing the burden on healthcare systems."

The Food and Drug Administration (FDA) approval followed the unanimous vote by the Antimicrobial Drugs Advisory Committee on the favorable benefit-risk profile of Beyfortus. It was based on the extensive clinical development program for Beyfortus, spanning three pivotal late-stage clinical trials.

Beyfortus was generally well tolerated, with a favorable safety profile consistent across all clinical trials.

Beyfortus has already been approved in the European Union and the United Kingdom.

According to the U.S. Centers for Disease Control and Prevention, RSV is a very contagious virus that can lead to serious respiratory illness in infants. Two out of three infants are infected with RSV during their first year of life, and almost all infants are infected by their second birthday.

The JAMA Network's Original Investigation in 2022 reported 6,549 respiratory fatalities were associated with RSV each year, including 96 (95% CI, 92-99) among children younger than one year.

RSV mAbs (Synagis) have been approved in the U.S. since 1998. Additionally, RSV vaccines have recently been approved by the FDA.