Press Release

Beyfortus real-world evidence published in The Lancet shows 82% reduction in infant RSV hospitalizations

Beyfortus real-world evidence published in The Lancet shows 82% reduction in infant RSV hospitalizations

• New real-world evidence shows Beyfortus (nirsevimab) substantially reduced RSV lower respiratory tract disease and hospitalizations in infants during the 2023-2024 RSV season, versus no intervention^1-6
• Results add to the consistent high efficacy of Beyfortus against medically attended RSV lower respiratory tract disease, shown in the pivotal clinical studies and the outcomes from HARMONIE, a phase 3b clinical study conducted in close to real-life conditions^7-10

Paris, May 2, 2024. Beyfortus reduced respiratory syncytial virus (RSV) hospitalizations by 82% (95% CI: 65.6 to 90.2) in infants under 6 months of age, compared to infants who received no RSV intervention, according to the interim results of an ongoing study published in The Lancet. These results, from the first RSV season after Beyfortus’ introduction, are part of the three-year NIRSE-GAL study conducted in Galicia, Spain under a collaborative framework with the Galician Directorate of Public Health of the Xunta de Galicia (Galician government) and Sanofi.¹

The results echo real-world evidence (RWE) reported from several broad infant immunization programs across the US, Spain and France during the 2023-2024 RSV season, which add to the consistent and high efficacy seen in pivotal clinical studies with Beyfortus. Real-world evidence demonstrates if a treatment or immunization is effective in day-to-day practice, as opposed to “efficacy” determined in carefully controlled clinical trials. A favorable safety profile was observed following Beyfortus use, consistent with clinical study results.^1-10

Federico Martinon Torres
Head of Pediatrics, Hospital Clínico Universitario Santiago, Spain and principal investigator of NIRSE-GAL study
“Galicia provides the first population-based real-world evidence of the impact of nirsevimab to prevent RSV disease in infants, showing a reduction by almost 90% in the number of hospitalizations due to this virus when compared with several previous RSV seasons. This achievement is the result of the exemplary pragmatic collaboration among scientists, industry, healthcare providers and policy makers aligned with a carefully planned roll-out of the immunization campaign, and the outstanding response of the Galician parents to this prophylaxis campaign.”