AstraZeneca and Sanofi’s nirsevimab successful in mid-stage study

A Phase 2 clinical trial evaluating AstraZeneca (NYSE:AZN) and development partner Sanofi’s (NASDAQ:SNY) nirsevimab for the passive immunization against respiratory syncytial virus (RSV) infections in healthy preterm infants met the primary endpoint demonstrating a 70.1% reduction in medically attended RSV lower respiratory tract infection (LRTI) compared to placebo through day 150 after dosing. The results were just published in the New England Journal of Medicine.

Treatment with nirsevimab, an extended half-life RSV monoclonal antibody, resulted in a 78.4% relative reduction in the incidence of hospitalization due to RSV LRTI through day 150, a secondary endpoint.

The rate of serious adverse events in the treatment arm was 11.2% versus 16.9% in the control arm, none deemed related to nirsevimab.

Passive immunization, which offers immediate protection, means that nirsevimab is given directly to an infant to help prevent RSV. Active immunization is when the person’s immune system is activated to prevent or fight infection via a vaccine, a process that could take weeks for protection to develop.

Phase 3 and Phase 2/3 studies are in process in full-term, healthy late preterm and high-risk infants.

https://seekingalpha.com/news/3597466-astrazeneca-and-sanofis-nirsevimab-successful-in-mid-stage-study