Food and Drug Administration staff seem to support approval of an antibody drug developed by AstraZeneca and Sanofi that’s meant to protect infants from infections caused by respiratory syncytial virus, or RSV.
Briefing documents were posted online ahead of a Thursday meeting of FDA advisers tasked with reviewing the drug, known as nirsevimab. Agency staff detailed the safety and efficacy data gathered by the two pharmaceutical companies, but did not appear to raise any major concerns with the clinical trial results.
RSV is a leading cause of hospitalization in young children, as well as in older people, causing severe respiratory infections that can be life-threatening. The only preventive drug for infants is palivizumab, an antibody therapy sold as Synagis. But its use is limited to babies at the highest risk of severe RSV infection, and it requires monthly injections.
Sanofi and AstraZeneca’s antibody drug is part of a wave of new RSV medicines that were made possible by a research breakthrough 10 years ago. In November, the EU cleared nirsevimab for young children, and last month, the FDA approved the first and second RSV vaccines for use in older adults.
For FDA approval, nirsevimab’s application is based on trials that tested its effectiveness in preventing RSV infections up to 150 days after an infant received the shot as well as its safety for about a year. Its risks were also compared to Synagis in high-risk infants. Last month, the companies published more data from a larger study.
The FDA advisers will vote on whether to recommend the FDA approve nirsevimab for use in infants during their first RSV season and in babies up to 24 months of age through their second RSV season. The FDA does not always follow recommendations from its advisers, but usually does.
The FDA is expected to decide whether it will approve nirsevimab by the third quarter.
“Given the unprecedented number of otherwise healthy infants who have been hospitalized with RSV this year in the U.S. and the recurrent pattern of RSV epidemics year after year, it is our intention to make nirsevimab available, if approved in time, for the 2023/2024 season to help alleviate the burden of RSV on families and the healthcare system,” said Thomas Triomphe, Sanofi’s head of vaccines, in a January statement when the FDA accepted its application.
Nirsevimab’s approval could come alongside another potential first for RSV prevention in infants. Last month, FDA advisers backed maternal use of Pfizer’s Abrysvo vaccine to protect newborns from RSV, and an agency decision is expected by August.
If approved, the shot could potentially be deployed in time for next RSV season.