RSV Therapy 83% Effective for Hospitalized Infants

Data published by Sanofi today from the HARMONIE Phase 3b clinical trial show an 83.21% (95% CI 67.77 to 92.04; P<0.001) reduction in hospitalizations due to RSV-related lower respiratory tract disease (LRTD) in younger infants who received a single dose of Beyfortus® (Nirsevimab).

While the U.S. Food and Drug Administration approved a multi-dose, injectable monoclonal antibody (mAbs) therapy in 1998, this new therapy has been authorized in Canada, Europe, and the U.K. as of May 12, 2023.

The Hospitalized RSV Monoclonal Antibody Prevention (HARMONIE) study is a large (8,000), multi-country interventional clinical trial aiming to determine the efficacy and safety of a single intramuscular dose of nirsevimab, with data collected in a real-world setting during the 2022-2023 RSV season. 

The data from HARMONIE also show that nirsevimab reduced the incidence of hospitalizations due to severe RSV-related LRTD (patients whose oxygen level is under 90% and require oxygen supplementation) by 75.71% (95% CI 32.75 to 92.91; P<0.001).

Additionally, nirsevimab demonstrated a reduction of 58.04% (95% CI 39.69 to 71.19; P<0.001) in the incidence of all-cause LRTD hospitalization compared to infants who received no RSV intervention.  

Throughout HARMONIE, nirsevimab maintained a favorable safety profile, consistent with the pivotal trial results.

In a press release, Dr. Simon Drysdale, Consultant Pediatrician in Infectious Diseases at St. George’s University Hospital NHS Foundation Trust and Co-Chief Investigator of HARMONIE, stated, “RSV-related chest infections lead to high numbers of infants under 12 months old being hospitalized every year."

"These data reinforce the potential public health benefit of nirsevimab in helping reduce the strain on hospitals caused each year by RSV.”

Additional RSV vaccine and monoclonal antibody news are posted by Precision Vaccinations.