Sanofi Nirsevimab Trial Shows 74.5% Reduction in RSV Infections
Sanofi's investigational antibody, nirsevimab, demonstrated a 74.5% reduction in medically attended lower respiratory tract infections caused by RSV in infants during a Phase 3 trial. The drug is being developed as a universal immunization.
Paris – Sanofi announced that its investigational antibody, nirsevimab, achieved a 74.5% reduction in medically attended lower respiratory tract infections (LRTI) caused by respiratory syncytial virus (RSV) in infants, according to Phase 3 trial results published in The New England Journal of Medicine.
The trial involved healthy infants born at term or late preterm (35 weeks gestational age or greater) entering their first RSV season. Nirsevimab is designed as the first long-acting antibody to protect all infants across the RSV season with a single dose.
A pooled analysis of RSV-associated hospitalizations from both Phase 3 and Phase 2b trials showed the proposed dose of nirsevimab demonstrated efficacy with a 77.3% reduction in hospitalizations among full-term and preterm infants (greater than 28 weeks gestational age). In the Phase 3 MELODY trial alone, a numerical reduction in the risk of RSV-associated hospitalizations was observed, though it did not reach statistical significance.
RSV is the most common cause of LRTI, including bronchiolitis and pneumonia, and a leading cause of hospitalization in all infants. Nirsevimab is being developed by Sanofi and AstraZeneca.