June 28, 2021: In positive topline results from the Phase 2/3 MEDLEY trial, nirsevimab showed a similar safety and tolerability profile compared to palivizumab when administered to preterm infants or those with chronic lung disease (CLD) or congenital heart disease (CHD) entering their first respiratory syncytial virus (RSV) season.
Safety and tolerability were assessed by the occurrence of all treatment emergent adverse events (TEAEs) and treatment emergent serious adverse events (TESAEs).
RSV, a seasonal virus that typically circulates in autumn through spring in temperate regions, is the most common cause of lower respiratory tract infections (LRTI) and the leading cause of hospitalizations in all infants.
“These data for nirsevimab are important as they show a safety and tolerability profile comparable to the only available preventative option against lower respiratory tract infections caused by RSV for preterm infants and those with health conditions,” said Dr. Joseph Domachowske, Professor of Pediatrics and Professor of Microbiology and Immunology at the State University of New York, Upstate Medical Center and MEDLEY trial primary investigator.
“Given the typical RSV season lasts nearly five months, there is a potential advantage to providing a preventative option that could help protect all infants with one dose for the entire season.”
MEDLEY is the third pivotal trial to report positive data for nirsevimab.
In April, Sanofi reported that nirsevimab met its primary endpoint of achieving a statistically significant reduction of LRTI caused by RSV in healthy preterm and term infants in the Phase 3 MELODY trial.
Coupled with recently published Phase 2b trial results, MELODY and MEDLEY results are part of a robust body of evidence demonstrating the potential of nirsevimab to provide RSV protection to all infants.
Results from the MELODY and MEDLEY trials will be presented at forthcoming scientific congresses and, along with the Phase 2b results, will form the basis of global regulatory submissions planned for 2022.
“RSV is the major remaining pediatric infectious disease with no preventative option available to all infants,” said Jean-François Toussaint, Global Head of Research and Development, Sanofi Pasteur.
“We believe nirsevimab has the potential to become an important and innovative routine immunization for all infants – those born prematurely or at term, healthy or with health conditions.”
“RSV is the leading cause of hospitalizations in infants,” said Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca.
“These results, combined with the recent positive efficacy outcome of our MELODY Phase 3 trial and our Phase 2b data, contribute to the body of evidence demonstrating nirsevimab’s potential to protect all infants against RSV with one dose. We look forward to sharing the results with regulators.”
Nirsevimab, being developed in partnership with AstraZeneca, is the first investigational extended half-life monoclonal antibody (mAb) aiming to protect all infants entering their first RSV season, when they are at highest risk for severe RSV disease.
With nirsevimab, the goal is to provide rapid and direct protection to the infant through a single immunization.
Nirsevimab is designed to be administered from birth to infants born during the RSV season or at the season’s start for infants entering their first RSV season.
In contrast to other options for RSV under development, such as maternal immunization, the aim of nirsevimab is to offer protection when needed to all infants entering their first season.
About the Phase 2/3 MEDLEY clinical trial
MEDLEY is a Phase 2/3, randomized, double-blind, palivizumab-controlled trial with the primary objective to evaluate the safety and tolerability of nirsevimab compared to palivizumab when administered to preterm infants entering their first respiratory syncytial virus (RSV) season and children with CLD and CHD entering their first and second RSV season.
Safety is assessed by monitoring the occurrence of TEAEs and TESAEs through 360 days post-dose.
Between July 2019 and May 2021 approximately 925 infants entering their first RSV season were dosed with either nirsevimab or palivizumab.
The evaluation of nirsevimab was carried out earlier than anticipated, based on sufficient enrollment, allowing for the assessment of nirsevimab’s safety and tolerability versus palivizumab in infants followed through their first RSV season.
The trial is ongoing to collect additional safety data in toddlers with CLD or CHD dosed prior to the second season.
Results from the MEDLEY trial will be presented at a forthcoming scientific congress.”
https://www.sanofi.com/en/media-room/press-releases/2021/2021-06-28-08-00-00-2253567
