FDA Committee Recommends Sanofi/AstraZeneca’s RSV Vaccine for Infants

FDA’s Antimicrobial Drugs Advisory Committee (AMDAC) voted unanimously 21 to 0 that Sanofi and AstraZeneca’s RSV prevention vaccine nirsevimab has a favorable benefit risk profile for newborns and infants born during or entering their first RSV season. The committee also voted 19 to 2 in support of nirsevimab’s favorable benefit risk profile for children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season, Sanofi said in a press release.

If approved, nirsevimab would be the first immunization specifically designed to protect all infants through their first RSV season, including those born healthy at term or preterm, or with specific health conditions that make them vulnerable to RSV disease, according to Sanofi.

Related: FDA Accepts BLA for RSV Prevention in Infants

The FDA accepted the biologics license application (BLA) for nirsevimab in January 2023, and the agency has indicated it will work to expedite its review. The Prescription Drug User Fee Act date is in the third quarter of 2023, according to Sanofi. If approved by that time, nirsevimab will be available in the United States ahead of the 2023-2024 RSV season.

William Muller, M.D., Ph.D.

“RSV remains the most common cause of bronchiolitis and pneumonia in infants, and the inability to predict which infants will develop severe RSV disease leads to uncertainty for new parents and for physicians,” said William Muller, M.D., Ph.D., associate professor of pediatrics at Northwestern University Feinberg School of Medicine and scientific directorof Clinical and Community Trials at Ann & Robert H. Lurie Children’s Hospital in Chicago. “The innovation of nirsevimab as a long-acting antibody that can be conveniently administered to a broad infant population with a single dose at the time protection is most needed is a significant public health advancement that could have far-reaching impact on the well-being of our families and healthcare systems in the U.S.”

Most babies hospitalized with RSV are born at term and healthy, which is why interventions specifically designed to protect all infants are likely to result in the greatest impact, said Thomas Triomphe, executive vice president, vaccines for Sanofi. “We are encouraged by the advisory committee’s positive vote based on the compelling clinical development program supporting nirsevimab and its breakthrough potential to reduce the magnitude of annual RSV burden.”

The AMDAC based its recommendation on the nirsevimab’s clinical development program that spans three pivotal late-stage clinical trials, including results from the phase 3 MELODY trial recently published in the New England Journal of Medicine.

Across all clinical endpoints, a single dose of nirsevimab demonstrated high and consistent efficacy against RSV LRTD sustained through the entire RSV season, Sanofi said. Nirsevimab was well tolerated with a favorable safety profile that was consistent across all clinical trials. The overall rates of adverse events were comparable between nirsevimab and placebo and the majority of adverse events were mild or moderate. The most common adverse events were rash, fever and injection site reactions, according to Sanofi.

Nirsevimab has been granted marketing authorization in the European Union, Great Britain and Canada for the prevention of RSV lower respiratory tract disease in newborns and infants from birth through their first RSV season. In Canada, nirsevimab is also approved for children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season and such indication is under review at the EMA level.