a The Food and Drug Administration’s advisory committee voted overwhelmingly on Thursday to recommend the approval of a monoclonal antibody product to protect newborns and young children against RSV.
The Advisory Committee on Antimicrobial Drugs voted unanimously to recommend the use of nirsevimab – which will be marketed as Beyfortus – in children in the first year of life. In a second vote, the committee voted 19 to 2 to recommend approval of the product for use in high-risk children in their second year of life.
The drug was developed by AstraZeneca. It will be marketed in the United States by Sanofi, which welcomed the commission’s recommendations.
“Most babies hospitalized with RSV are born full term and healthy, so interventions specifically designed to protect all babies are likely to have the greatest impact,” said Thomas Triomphe, Sanofi’s executive vice president for vaccines. , after the results of the first votes were announced.
“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 the annual RSV burden.”
RSV is a major cause of illness in young children. It is estimated that each year about 400,000 children in this country go to a doctor’s office or medical clinic for care for lower respiratory infections caused by RSV, about 150,000 go to the emergency room, and between 58,000 and 80,000 end up hospitalized with the disease. It is estimated that between 100 and 300 children die of RSV infection each year in this country.
The infection is often most severe in very young children, whose lungs are still developing. Designing a vaccine for use in this age group would be challenging, as several doses may be needed, over a period of weeks or months, to generate protection – a time when infants are still vulnerable to RSV.
Pfizer has come up with a rival approach by developing a vaccine — if approved — that will be administered during pregnancy. The antibodies the pregnant person develops are shared with the fetus in the womb, meaning that babies born to vaccinated people will have some protection in the first months of life. That vaccine is also making its way through the regulatory process.
The AstraZeneca-Sanofi approach means that babies receive a single injection of antibodies against RSV, either at birth, if they are born during RSV season, or in the fall, if they are born at a different time of the year . In normal years, the RSV season lasts about five months, usually starting around November and peaking in January or February.
Data presented to the committee by AstraZeneca suggested strong protection for at least five months after administration. In a randomized controlled trial, infants receiving nirsevimab saw their risk of RSV infection requiring medical attention reduced by 70% and their risk of being hospitalized for RSV infection by 78.4%.
Committee members – many of whom are pediatricians – were excited about the treatment’s potential, noting that the annual rush of RSV cases is overwhelming children’s hospitals, endangering care not only for children with RSV, but also for any child requiring hospital care.
And they praised AstraZeneca for conducting good, thorough studies in the challenging context of the Covid-19 pandemic.
But they noted that there are still questions to be answered, and urged both the companies and the FDA on the importance of further research.
There is no data, several pointed out, on whether giving nirsevimab to a baby whose mother was vaccinated against RSV during pregnancy would give the baby more protection or would be a waste of the product. And several committee members feared that the dose given in the first year of life could be too small for a baby who was 8 months or older when he received the shot, depending on the baby’s size.
Igovwhera Ofotokun, an infectious disease professor at Emory University School of Medicine, expressed concern about how nirsevimab will be used in warmer parts of the country, where RSV is not a winter disease. Tonya Villafana, vice president of AstraZeneca and head of the global vaccines and immunotherapies franchise, said the company would work with the FDA and other experts to figure out how best to use nirsevimab in such settings.
Committee chair Lindsey Baden, director of clinical research in the infectious disease division at Brigham and Women’s Hospital, also stressed the need for ongoing safety monitoring. While there were no safety signals in the clinical trials, he said, “safety in 3,000.” [children] is no safety in 3 million.”
The FDA is not obligated to follow the committee’s advice, but it seems unlikely that it would ignore these recommendations given the great need for tools to protect children against respiratory syncytial virus, the No. 1 cause of hospitalizations. in infants in this country.
But if the FDA approves Beyfortus, the final word on how it will be used and with whom will rest with the Centers for Disease Control and Prevention, and its expert panel, the Advisory Committee on Immunization Practices. The ACIP can only vote on whether or not to recommend the use of the monoclonal agent after the FDA has approved the product.
