The drug, which is a single dose long-acting antibody, is aimed at the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in newborns and infants entering or during their first RSV season, and for children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.
Under the terms of their agreement, AstraZeneca leads all development and manufacturing activities related to nirsevimab, and Sanofi leads commercialization activities and records revenue for the drug, which is the first single-dose preventative option for the broad infant population, including those born healthy, at term or preterm, or with specific health conditions.
The companies said the FDA has indicated it will work to expedite its review.
The antibody has already been given the green light in the EU. November 2022 saw nirsevimab granted marketing authorization by the European Commission for the prevention of RSV lower respiratory tract disease in newborns and infants during their first RSV season, under the name Beyfortus.
And additional global regulatory submissions are underway, confirmed the partners.
The submission to the US regulator was supported by a comprehensive clinical trial program, which demonstrated protection against RSV disease through the RSV season, including the MELODY Phase III (primary cohort and all subjects), MEDLEY Phase II/III (first and second RSV season), and Phase IIb trials.
The companies say the antibody’s advantage is that one dose offers several months of protection against severe disease in infants.
RSV is a very contagious virus that can lead to serious respiratory illness for infants, according to the Centers for Disease Control and Prevention (CDC). A paper in the Journal of Infectious Diseases reported that any infant can be hospitalised in their first RSV season and about 75% of infants hospitalised for RSV in the US were born at term with no underlying conditions.
Data from the MELODY trial was published in the New England Journal of Medicine in March 2022 and demonstrated a reduction in the incidence of medically attended lower respiratory tract infections (LRTI) caused by RSV by 74.5% compared to a placebo, through day 151, with a single dose.
Nirsevimab also demonstrated a comparable safety and tolerability profile to Synagis (palivizumab) in the MEDLEY Phase II/III trial, with occurrence of treatment emergent adverse events (TEAEs) or treatment emergent serious adverse events (TESAEs) similar between groups, said the developers.
“Effective interventions to prevent RSV are a critical need. This year in the US, we’ve seen first-hand how frightening the impact of this respiratory disease is on our patients and how stressful it is on the healthcare system, highlighting the urgency of addressing this problem,” commented Dr William Muller, associate professor, Pediatrics, Northwestern University Feinberg School of Medicine.