Merck & Co. (MRK, Financial) announced that the U.S. FDA has accepted its Biologics License Application (BLA) for clesrovimab (MK-1654), a long-acting monoclonal antibody in development. This antibody aims to protect infants from Respiratory Syncytial Virus (RSV) during their first RSV season. Clinical data shows clesrovimab reduced RSV-related hospitalizations by over 84% and lower respiratory infections by more than 90% within five months. The FDA is expected to complete its review by June 2025.
Clesrovimab is a passive immunity approach with extended half-life, evaluated in key Phase 2b/3 trials. The CLEVER trial assessed its efficacy in healthy infants, while the SMART trial compared its safety and efficacy with palivizumab in high-risk children. Results were presented at the 2024 IDWeek conference.
