Beyfortus (nirsevimab) is a drug intended to prevent respiratory syncytial virus (RSV) infection in newborns and infants from developing lower respiratory tract diseases such as bronchiolitis (inflammation of the small airways in the lungs) or pneumonia (infection of the lungs). The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has recommended that a marketing authorization be granted in the European Union for this medicine, which has been jointly developed by Sanofi and AstraZeneca.
The EMA now recommends the use of Beyfortus in “newborns and infants during their first season of virus circulation”, when there is a risk of RSV infection in the community. Once approved by the EC, it would be the first and only drug to prevent RSV that could be injected into all babies under 1 year of age. Another antibody, palivizumab, is currently available and is marketed under the name Synagis (AstraZeneca), but it is only administered to premature or at-risk children.
Respiratory syncytial virus usually causes mild cold-like symptoms and usually clears up within a week or two. But in some cases, especially in babies, it can be serious, being the most common cause of lower respiratory tract infections such as bronchiolitis and pneumonia that can lead to hospitalization or even death in newborns and young children. According to data from 2015, RSV caused around 33 million lower respiratory tract infections in children under five years of age worldwide; of which 10% required hospitalization, and an estimated 59,600 children died, the vast majority (43,600) in low- and middle-income countries. Although the number of cases fell sharply during the pandemic, a resurgence in infections is expected this winter following the relaxation of COVID-19 mitigation measures.
Beyfortus is not exactly a vaccine, but a preventive treatment that is administered with a intravenous injection with which an antibody “designed to adhere to the protein (…) that the virus needs to infect the body is introduced. When nirsevimab binds to this protein, the virus cannot enter the cells of the body”, according to the EMA. It is a prevention indicated for newborns who have not yet fully developed their immune system.
A dose of Beyfortus immunizes the baby against RSV
The recommended dose of Beyfortus is a single 50 mg intramuscular injection for infants weighing less than 5 kg, and a single 100 mg intramuscular injection for infants weighing 5 kg or more. The most common side effects are skin rash, fever, and pain and swelling at the injection site.
“This is one of the most important public health achievements related to RSV in decades. We are one step closer to achieving our goal of protecting all infants from RSV with a single dose.”
The CHMP’s positive opinion is based on clinical trials examining the efficacy and safety of nirsevimab in healthy preterm and term infants during their first RSV season. The results of these studies showed that Beyfortus prevents RSV lower respiratory tract infection requiring medical attention (such as bronchiolitis and pneumonia) in full-term and premature babies during their first season of RSV.
“Today’s positive CHMP opinion is one of the most important public health achievements related to RSV in decades and has the potential to alleviate the enormous physical and emotional burden that RSV can place on families and healthcare systems. . With this approval, we are one step closer to achieving our goal of protecting all infants against RSV with a single dose,” said Jean-François Toussaint, Global Head of Vaccine Research and Development at Sanofi.
AstraZeneca Executive Vice President of Biopharmaceuticals R&D, Mene Pangalos, added: “This positive opinion from the CHMP underlines the potential of Beyfortus as a first-in-class, innovative passive immunization that could transform the approach of the medical community for the prevention of RSV in infants”.
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