As of 26 April, the likelihood of approval (LoA) score for the RSV antibody respiratory syncytial virus (RSV) drug nirsevimab that is being developed by AstraZeneca and Sanofi climbed up 8 points. This change was prompted by an announcement on the same day stating that the Phase II/III MELODY trial investigating nirsevimab met its primary endpoint.

Data from MELODY will be part of nirsevimab’s regulatory submission slated for early 2022. Additionally, results from a Phase II/III MEDLEY trial comparing nirsevimab to Swedish Orphan Biovitrum’s Synagis (pavulizumab) in infants, and a Phase IIb study will also be part of the package. While detailed MELODY results are pending, nirsevimab reduced the incidence of medically attended lower respiratory tract infections (LRTI) due to RSV compared to placebo in healthy late preterm and term infants during their first RSV season, as per the 26 April press release. Nirsevimab has an extended half-life and is administered via a one-time intramuscular injection, while Synagis is administered monthly throughout the RSV season.

The LoA score which is calculated by GlobalData’s analysis that uses a combination of machine learning and a proprietary algorithm, was originally 36 points and is now at 44 points. While Synagis is only indicated for infants at high risk of RSV disease, nirsevimab is intended for use in all infants experiencing their first RSV season. As per an analyst’s best-case scenario, nirsevimab could rake in $1bn in peak sales. Global nirsevimab sales are estimated to reach $560m as per GlobalData Consensus forecast. AstraZeneca and Sanofi’s market caps are £101.27bn ($140bn) and €108.99bn ($131.14bn) respectively.

Manasi Vaidya is a Associate Editor for Clinical Trials Arena parent company GlobalData’s investigative journalism team. A version of this article originally appeared on the Insights module of GlobalData’s Pharmaceutical Intelligence Center. To access more articles like this, visit GlobalData.