Sanofi-AstraZeneca Say New Nirsevimab Data Reinforce Efficacy Against RSV

  • Sanofi SA SNY and AstraZeneca plc AZN have announced results from a prespecified pooled analysis of nirsevimab in respiratory syncytial virus (RSV).
  • Results from the Phase 3 MELODY and Phase 2b nirsevimab trials demonstrated an efficacy (relative risk reduction versus placebo) of 79.5% against medically attended lower respiratory tract infections due to RSV in infants.
  • In a separate pooled posthoc analysis of the trials, blood samples taken from infants dosed with nirsevimab exhibited RSV neutralizing antibodies that were approximately 50-fold higher than baseline at Day 151 post-dose. 
  • Related: AstraZeneca-Sanofi's Nirsevimab Shows 75% Efficacy Against RSV In Healthy Infants.
  • RSV neutralizing antibody levels remained greater than 19-fold higher than placebo recipients with no known RSV infection through Day 361, suggesting protection may extend beyond Day 151.
  • As reported in previous trials, the safety profile across the nirsevimab and placebo groups remains similar.
  • Nirsevimab is the first investigational immunization designed to protect all infants across the RSV season with a single dose.
  • Price Action: SNY shares are down 1.36% at $51.46, and AZN stock is down 2.18% at $62.25 during the premarket session on the last check Wednesday.
Posted In: BiotechLarge CapNewsHealth CareGeneralBriefsREspiratory syncytial virus