Palivizumab is a monoclonal antibody used as RSV immunoprophylaxis in pediatric patients at high risk for severe RSV lower respiratory tract disease. It is administered intramuscularly on a monthly schedule during RSV season. It is not indicated for treatment of active RSV disease.
A real-world study in Galicia showed nirsevimab reduced RSV-related hospitalizations by 85.9% in the first season and 55.3% in the second. The RSV prevention market is expanding to cover high-risk children, with Beyfortus the only antibody approved for second-season use. The FDA has cited Sanofi for misleading promotional claims about the product.
Merck's Enflonsia (clesrovimab) receives EU approval for RSV prevention in infants. Separately, researchers identify a monoclonal antibody cocktail from pediatricians' immune cells that shows potent protection against RSV and hMPV in animal studies.
The European Commission approved Enflonsia for prevention of RSV lower respiratory tract disease in infants during their first RSV season. Merck also reported new Phase 3 SMART data showing generally consistent second-season safety in high-risk children under 2 years old.
Phase III SMART trial data show clesrovimab maintained consistent safety and efficacy in high-risk children across two RSV seasons, with no drug-related serious adverse events reported in either season.
| NCT ID | Title | Status | Phase |
|---|---|---|---|
| NCT04938830 |
Clesrovimab (MK-1654) in Infants and Children at Increased Risk for Severe Respiratory Syncytial Virus (RSV) Disease (MK-1654-007) |
COMPLETED | PHASE3 |
