Positive results from phase IIb trial of nirsevimab to treat infants with respiratory syncytial virus.Sanofi + AstraZeneca

Detailed results from the positive Phase IIb trial for nirsevimab from Sanofi, + AstraZeneca, showed a significant reduction in medically attended lower respiratory tract infections (LRTI), mainly bronchiolitis and pneumonia, and hospitalizations caused by respiratory syncytial virus (RSV) in healthy preterm infants. Published in the New England Journal of Medicine, results from this trial demonstrate for the first time that a single dose monoclonal antibody can significantly reduce medically attended RSV LRTI in infants through the full RSV season. “The data for nirsevimab are exciting, as they highlight the potential for this innovative approach to protect infants from RSV with just one injection for the entire season,” said Dr. Joseph Domachowske, study author, Professor of Pediatrics, Professor of Microbiology and Immunology, and Director of the Global Maternal-Child and Pediatric Health Program at the SUNY Upstate Medical University. “Nirsevimab offers the important potential to reduce hospitalizations and emergency department and in-office visits, which are a significant burden for healthcare systems.” Nirsevimab is an extended half-life RSV monoclonal antibody (mAb), being developed in partnership with AstraZeneca as a passive immunization, meaning a protective antibody is administered directly to an infant to help prevent RSV. Nirsevimab could set a new standard of care by offering an innovative immunization for immediate and sustained protection for all infants during their first RSV season, when they are most at risk for infection or complication. Ninety percent of all babies will be infected with RSV before the age of two. The Phase IIb trial met primary and secondary endpoints. On the primary endpoint, nirsevimab achieved a statistically significant 70.1% (95% CI: 52.3%-81.2%) reduction of medically attended RSV LRTI compared to placebo through 150 days post-dose. On the secondary endpoint, nirsevimab achieved a 78.4% (95% CI: 51.9%-90.3%) relative reduction in the incidence of hospitalizations due to RSV LRTI compared to placebo through 150 days post-dose. The safety profile for nirsevimab was similar to placebo, with no significant hypersensitivity reactions observed. See-" Single-Dose Nirsevimab for Prevention of RSV in Preterm Infants".: M. Pamela Griffin, M.D., Yuan Yuan, Ph.D., Therese Takas, B.S., Joseph B. Domachowske, M.D., et al., for the Nirsevimab Study Group.July 30, 2020N Engl J Med 2020; 383:415-425 DOI: 10.1056/NEJMoa1913556. Under the terms of the global agreement Sanofi and AstraZeneca will share all costs and profits equally. AstraZeneca will continue to lead all development activity through initial approvals, and AstraZeneca will retain nirsevimab manufacturing activities. Sanofi-Pasteur will lead commercialisation activities.