Another RSV Monoclonal Antibody for Infants Coming in 2025

Merck today announced the U.S. Food and Drug Administration (FDA) has accepted the Biologics License Application (BLA) for clesrovimab, the company’s investigational prophylactic long-acting monoclonal antibody designed to protect infants from respiratory syncytial virus (RSV) disease during their first RSV season.

The FDA has set a Prescription Drug User Fee Act date of June 10, 2025.

Dr. Paula Annunziato, senior vice president of infectious diseases and vaccines, Global Clinical Development, Merck Research Laboratories, commented in a press release on December 17, 2024, “We look forward to working alongside the FDA on the review of clesrovimab, which, if approved, would be the first and only single-dose immunization for infants regardless of weight designed to protect them for the duration of their first RSV season.”

If approved, Merck anticipates that clesrovimab shipments will arrive in time for the 2025 RSV season.

Currently, Beyfortus™, an FDA-approved extended half-life monoclonal antibody, is available in the U.S.