Nirsevimab significantly protected infants against RSV disease in phase III MELODY trial- Sanofi + AstraZeneca

Additionally, the MEDLEY Phase II/III trial, which evaluated safety and pharmacokinetics of nirsevimab in infants with congenital heart disease (CHD), chronic lung disease (CLD) and prematurity entering their first RSV season, demonstrated nirsevimab had a similar safety and tolerability profile compared to Synagis (palivizumab).Serum levels of nirsevimab following dosing (on day 151) in this trial were comparable with those observed in the MELODY Phase III trial, indicating similar protection in this population to that in the healthy term and late preterm infants is likely. Synagis is currently the only available preventative option for RSV.

Nirsevimab is an investigational long-acting antibody designed to protect all infants through their first RSV season with a single dose. It is the first potential immunisation to show protection against RSV in the general infant population in a Phase III trial.

A prespecified pooled analysis of the MELODY and Phase IIb trials demonstrated a reduction of hospitalisations caused by RSV with the proposed dose of nirsevimab. In term and preterm infants (greater than 28 weeks gestational age), 21 of 786 (2.7%) infants in the placebo arm compared to nine of 1,564 (0.6%) in the nirsevimab arm experienced an RSV-associated hospitalisation, giving an estimate of efficacy of 77.3% (95% CI 50.3, 89.7; P<0.001) through 150 days postdose. there was numerical reduction, although not statistically significant, of the risk of rsv associated hospitalisations observed in the melody trial alone (62.1%, 95% ci: -8.6, 86.8, p="0.07)." in the nirsevimab arm, six of 994 (0.6%) infants were hospitalised for rsv lrti, while eight of 496 infants (1.6)% were hospitalised in the placebo arm. the overall safety profile of nirsevimab remains consistent with previously reported results. no clinically meaningful differences in safety results between the nirsevimab and placebo groups were seen in melody and phase iib. melody trial results were published in the new england journal of medicine (nejm). details from the medley trial were also published in the nejm. regulatory submissions began in the first half of 2022.></0.001)>

See-"Nirsevimab for Prevention of RSV in Healthy Late-Preterm and Term Infants"; Laura L. Hammitt, M.D., Ron Dagan, M.D., Yuan Yuan, Ph.D., et al., for the MELODY Study Group. March 3, 2022. N Engl J Med 2022; 386:837-846 .DOI: 10.1056/NEJMoa2110275.