- Nirsevimab is being investigated as a first-in-class single dose immunization to provide protection for all infants entering their first RSV season.
- Nirsevimab met its Phase 3 primary endpoint earlier than anticipated; regulatory submissions for all-infant indication to begin in 2022.
Positive topline results from the Phase 3 MELODY trial showed nirsevimab reduced lower respiratory tract infections (LRTI) requiring medical attention (inpatient or outpatient) due to respiratory syncytial virus (RSV) in healthy preterm and term infants. RSV is the most common cause of LRTI and the leading cause of hospitalizations in all infants.
Nirsevimab reached its primary endpoint, achieving a statistically significant absolute reduction of LRTI caused by RSV in healthy preterm and term infants compared to placebo through a typical RSV season. No clinically meaningful differences in safety results between the nirsevimab and placebo groups were seen. The overall safety profile of nirsevimab in the trial remains consistent with previously reported results.
Results will be presented at an upcoming scientific congress and are anticipated to form the basis of regulatory submissions.
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, a protective antibody is administered directly to the infant with the goal of providing rapid protection.
In contrast to other options for RSV under development, such as maternal vaccines, nirsevimab was designed to be administered at birth to infants born during the RSV season or at the season’s start for infants born prior to the season.