FDA Approves New Manufacturing Line for Sanofi and AstraZeneca's RSV Antibody

The U.S. Food and Drug Administration (FDA) has approved a new filling line for the respiratory syncytial virus (RSV) antibody Beyfortus, developed by Sanofi and AstraZeneca. This approval is crucial for expanding the production capacity of Beyfortus, which is designed to immunize newborns and infants against RSV. The move aims to meet the anticipated demand for the 2024/2025 RSV season in the United States.

The newly approved filling line will enable the production of both 50-mg and 100-mg doses of Beyfortus. These doses will be distributed to private healthcare providers and to the Centers for Disease Control and Prevention (CDC) for its Vaccines for Children program. According to Sanofi, this will ensure that every eligible baby born outside the RSV season can receive the immunization during regular checkups, while those born during the season can receive the antibody at birth.

AstraZeneca, responsible for the development and manufacturing of Beyfortus, has already produced and packaged several doses of the antibody. With the FDA's approval of the new filling line, the companies are prepared to ship these doses and increase the supply in the Northern Hemisphere before the upcoming RSV season.

Thomas Grenier, head of vaccines, North America at Sanofi, highlighted that this achievement was a result of close collaboration with various health authorities, including the White House, CDC, FDA, and healthcare providers. Grenier emphasized that the newly approved filling line would help make Beyfortus widely available to those in need.

In addition to the newly approved filling line, Sanofi and AstraZeneca are preparing another filling line to provide additional doses for the 2024/2025 season. Beyfortus is a long-acting antibody that provides passive immunity to RSV by targeting and binding to the virus, preventing it from entering host cells and thereby blocking infection at a cellular level.

In July 2023, the FDA approved the use of Beyfortus for infants entering their first RSV season and for children up to 24 months old who are at high risk of severe infection during their second RSV season. Furthermore, in March 2024, a CDC analysis demonstrated that Beyfortus is highly effective in infants, showing a 90% efficacy in preventing RSV-related hospitalizations. These findings support the CDC's recommendation for maternal RSV vaccination or infant immunization with nirsevimab as protective measures.

RSV vaccines are also being developed to prevent infections in adults. In May 2023, GSK's Arexvy became the first FDA-approved RSV vaccine for adults aged 60 and above. The label was expanded in June 2024 to include younger seniors aged 50 to 59. Pfizer is also involved in the RSV vaccine market with its product Abrysvo, first approved in June 2023. Abrysvo has since been approved for pediatric immunization through maternal injection during the gestation period of 32 to 36 weeks.