Clesrovimab FDA Approval: RSV Prevention in Infants
The FDA has authorized Enflonsia (clesrovimab-cfor) for RSV prevention in newborns and infants. This marks a significant advancement in safeguarding vulnerable young children against lower respiratory tract disease. merck’s Enflonsia, a long-acting monoclonal antibody, provides approximately five months of protection with a single dose. Clinical trials established the efficacy of clesrovimab, which Dr. Octavio Ramilo confirmed can significantly reduce RSV-related hospitalizations. News Directory 3 is committed to providing you with the latest updates on critical health developments. Learn more about how this approval will impact upcoming RSV seasons.
FDA Approves Merck’s Enflonsia for RSV Prevention in Infants
Updated June 9, 2025
The food and Drug Governance has given the green light to Merck’s Enflonsia (clesrovimab-cfor) for preventing lower respiratory tract disease caused by respiratory syncytial virus (RSV) in newborns and infants. This approval targets those born during or entering their initial RSV season, offering a new preventative measure against this common virus.
The FDA’s decision stems from the phase 2b/3 CLEVER trial, which assessed the impact of a single clesrovimab dose on preterm and full-term infants from birth to one year old. The study demonstrated the effectiveness of clesrovimab in providing RSV prevention.
Dr. Octavio Ramilo, chair of infectious diseases at St. Jude Children’s Research Hospital and a CLEVER trial investigator, highlighted the meaning of this approval. “RSV disease is the leading cause of infant hospitalization in the U.S.,” Ramilo said in a news release,noting that it can lead to serious conditions like bronchiolitis and pneumonia. He added that Enflonsia offers both convenience and strong clinical data, showing significant reductions in RSV incidence and hospitalizations.
Enflonsia, a long-acting monoclonal antibody, is administered as a 105 mg dose. It is designed to provide rapid and sustained protection for approximately five months,which aligns with the typical RSV season,irrespective of the infant’s weight.
“[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.”
What’s next
with the FDA approval secured, Merck plans to rapidly roll out Enflonsia to healthcare providers across the U.S., ensuring timely access to this crucial preventative treatment for at-risk infants during the upcoming RSV season.