Study compares RSV antibody response of nirsevimab and palivizumab

October 4, 2024

Relative to palivizumab, nirsevimab confers roughly 10-fold higher and more sustained RSV neutralizing antibody (nAb) levels.

The phase 2/3 randomized, controlled MEDLEY trial was conducted during 2 RSV seasons (season 1 and 2) and included infants born preterm (≤35 weeks' gestational age; dosed during season 1 only) or with congenital heart disease or chronic lung disease of prematurity (dosed during both season 1 and 2). Participants were randomly assigned to receive a single dose of nirsevimab followed by 4 monthly placebo doses, or 5 once-monthly doses of palivizumab.

A high correlation between nAb levels and nirsevimab and palivizumab serum concentrations was seen in both seasons. In season 1, nAb levels in the nirsevimab group were highest at day 31 and gradually declined but remained 17-fold above baseline at day 361. nAb levels in palivizumab recipients increased incrementally with monthly doses to day 151. Across both seasons, nAb levels were ∼10-fold higher with nirsevimab vs. palivizumab.

Source:

Wilkins D, et al. (2024, October 1). Pediatrics. RSV Neutralizing Antibodies Following Nirsevimab and Palivizumab Dosing. https://pubmed.ncbi.nlm.nih.gov/39350745/