Will U.S. FDA Approve RSV Immunization for Infants
A meeting of the U.S. FDA's Antimicrobial Drugs Advisory Committee is scheduled for June 8, 2023, to discuss the biologics license application (BLA) for nirsevimab (Beyfortus®), a long-acting respiratory syncytial virus (RSV) F protein inhibitor, single dose monoclonal antibody (mAbs).
Submitted by AstraZeneca AB, the proposed indication prevents RSV lower respiratory tract disease in neonates and infants born during or entering their first RSV season and children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.
While the FDA has authorized two RSV vaccines for older people, it has been about twenty-five years since the agency approved mAbs to prevent RSV infections in infants.
AstraZeneca (SOBI) Synagis® (Palivizumab) was approved in 1998 and is a multi-dose injectable RSV antibody limited to high-risk infants requiring five injections to cover an RSV season.
On June 6, 2023, the Pan American Health Organization suggested Synagis prophylaxis should be administered during the first year of life to infants with hemodynamically significant heart disease or chronic lung disease of prematurity (<32 weeks gestation who require >21% O2 for the first 28 days of life).
With a half-life of approximately one month, Synagis must be administered monthly.
AstraZeneca (the Sponsor), in partnership with Sanofi, is seeking marketing approval for nirsevimab. The clinical data summarized in this briefing document show that nirsevimab is safe and efficacious, supporting the favorable benefit-risk of nirsevimab for the proposed indication.
The committee will discuss to questions:
- Is the overall benefit-risk assessment favorable for using nirsevimab to prevent RSV lower respiratory disease in neonates and infants born during or entering their first RSV season?
- Is the overall benefit-risk assessment favorable for using nirsevimab to prevent RSV lower respiratory tract disease in children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season?
The European Commission granted Beyfortus worldwide approval on November 4, 2022, followed by authorizations from the U.K. and Canada.
Prevention of RSV illnesses in all infants is a major public health priority, and respiratory syncytial virus LRTI is the most common reason for admission to hospital in infants < 1 year of age.
All children, including healthy term infants, are at risk for severe RSV LRTI with primary RSV infection during infancy.
Overall, 72% of infants admitted to the hospital with RSV LRTI are born at term and have no underlying serious comorbidity.
Beyond their first RSV season, some children with serious underlying comorbidities remain vulnerable to severe RSV LRTI, including infants with prematurity, chronic lung disease, congenital heart disease, cystic fibrosis, neuromuscular conditions, Down syndrome, or immunocompromised states.
A YouTube broadcast of the meeting can be accessed at: https://youtube.com/live/L2OYN6mjzCE. Please note that the YouTube live video of the meeting will not broadcast until the session begins at approximately 9:30 a.m. ET on June 8, 2023.