Europe 1 with AFP 18:18 p.m., May 12, 2023

Nirsevimab, the first approved preventive treatment against the respiratory syncytial virus that causes bronchiolitis, is said to have prevented 83.21% of hospitalizations in babies under one year of age. This finding is the result of a phase three study carried out on more than 8,000 children in France, Germany and the United Kingdom.

The French laboratory Sanofi claimed Friday "very promising results" after a large study carried out on its preventive treatment nirsevimab, co-developed with the British AstraZeneca, aimed at reducing the risk of hospitalization for infants with respiratory syncytial virus (RSV). This drug, the world's first approved preventive treatment against RSV, which causes bronchiolitis, has "prevented 83.21% of hospitalizations in infants under twelve months of age who received a single dose of nirsevimab, compared to infants who received no intervention" against the virus, Sanofi said in a statement.

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Marketing authorisation

This finding is the result of a phase three study conducted on more than 8,000 children in France, Germany and the United Kingdom, using data collected in real situations during the 2022-2023 RSV circulation season. "The overall burden on health systems could be significantly reduced if nirsevimab were given to all infants. In 2017, healthcare spending directly related to RSV (including in-hospital, outpatient and follow-up care) was estimated at €4.82 billion worldwide, Sanofi said.

Currently, nine out of ten children are infected with RSV before the age of two. Although the infection is generally not serious, nearly one in three children who present to the emergency room for bronchiolitis require hospitalization. According to the French national study conducted from 2010 to 2018, an average of 50,878 children under the age of five are hospitalized because of RSV each year. Among them, children under one year of age account for more than 69% of hospitalizations, or more than 35,000 children per year, says Sanofi.

Nirsevimab has currently received marketing authorization in the European Union, the United Kingdom and Canada for the prevention of lower respiratory syncytial virus infections in neonates and infants during their first RSV exposure season. In addition, its application for approval in the United States is under consideration.