Merck's (MRK.US) preventive long-acting monoclonal antibody clesrovimab's application for marketing authorization has been accepted by FDA.

Merck & Co., Inc. (MSD) (MRK.US) today announced that the U.S. FDA has accepted the company's Biologics License Application (BLA) for the investigational long-acting monoclonal antibody clesrovimab (MK-1654) for the prevention of respiratory syncytial virus (RSV) disease in infants during their first RSV season. Data showed that clesrovimab reduced the rate of RSV-related hospitalizations by 84% and the rate of RSV-related lower respiratory tract infections (LRI) by over 90% over a five-month period.

The FDA is scheduled to complete its review by June 10, 2025. Clesrovimab is an investigational extended half-life monoclonal antibody for the prevention of RSV disease as a passive immunization. The application is based on the results of the pivotal 2b/3 phase clinical trial CLEVER, a randomized, placebo-controlled trial evaluating a single dose of clesrovimab in healthy preterm and term infants; and the interim results of the ongoing phase 3 clinical trial SMART, evaluating the safety and efficacy of clesrovimab in combination with palivizumab in high-risk infants and children. These data were presented at the 2024 Infectious Diseases Week (IDWeek) meeting in October 2024.