FDA advisers endorse antibody therapy to protect against RSV in infants and some young toddlers

CNN

The US Food and Drug Administration's advisory board voted on Thursday to support a monoclonal antigen therapy that is designed to protect babies and young toddlers against RSV.

The Antimicrobial Drugs Advisory Committee of the Agency voted that nirsevimab's benefit-risk profile was favorable for infants, and that it was favorable for children aged up to 24 months susceptible to severe respiratory syncytial viruses.

The FDA will then consider the advice from the advisors and decide if the treatment is approved.

AstraZeneca developed the monoclonal antigen, nirsevimab. The monoclonal antibody, nirsevimab, was developed by AstraZeneca and Sanofi.

It will be the first preventive treatment that is administered in a single dose to all infants. A monoclonal anti-body works immediately, unlike a vaccine that builds immunity over time.

Comparing nirsevimab to a placebo, the drug reduced hospitalizations and RSV-related lower respiratory tract infections by 75%. There were no major safety concerns identified. Some common side effects included rash and injection site reactions.

Palivizumab (also known as Synagis) is another monoclonal anti-body treatment that has been approved in Europe and the US to protect high-risk babies from infection. Infants receive an intramuscular injection each month during RSV seasons.

The FDA's vaccine advisors voted last month in favor of a new RSV vaccine for infants. This maternal vaccine is a one-dose shot given to pregnant women late in pregnancy. It triggers the production of antibodies which are then passed to the baby and provides protection for the first six months. The vaccine made by Pfizer has been shown to reduce the likelihood that an infant will need to be seen by a doctor, or admitted to hospital, with a mild to moderate infection.

According to the US Centers for Disease Control and Prevention (CDC), nearly every child contracts RSV by the time they reach the age of two. But last winter the virus ravaged pediatric hospitals across the United States. Even though it's a milder infection in children and adults, it's still the leading cause of infant hospitalization.

In 2019, there were more than 3.6 millions hospitalizations and 33 million cases worldwide. According to a study published in 2022 in The Lancet, there were estimated to be 26,300 RSV-related deaths in hospital for children under 5 years old and 101,400 overall.