The food and Drug Administration (FDA) has granted approval to clesrovimab-cfor (Enflonsia; Merck) for the prevention of lower respiratory tract disease caused by respiratory syncytial virus (RSV) in newborns and infants. This approval applies to infants born during, or entering, their first RSV season.

The decision is supported by data from the phase 2b/3 CLEVER trial (NCT04767373), which assessed the impact of a single dose of clesrovimab in preterm and full-term infants from birth to 1 year of age.

Clinical Trial Results and Expert commentary

According to a news release, Octavio Ramilo, MD, chair of the department of infectious diseases at St. Jude Children’s Research Hospital and investigator for the CLEVER trial,stated that “RSV disease is the leading cause of infant hospitalization in the US and can lead to serious respiratory conditions like bronchiolitis and pneumonia.” He added, “[Clesrovimab] combines dosing convenience with strong clinical data showing significant reductions in RSV disease incidence and hospitalizations, making it a promising new intervention to help protect infants from RSV.”

“[Clesrovimab] combines dosing convenience with strong clinical data showing significant reductions in RSV disease incidence and hospitalizations.”

Clesrovimab is a long-acting, preventive, monoclonal antibody. A single 105 mg dose is designed to provide rapid and sustained protection for approximately 5 months, which covers the typical RSV season, irrespective of the infant’s weight.