- Phase 3 SMART trial results for ENFLONSIA were presented at the 9th RSVVW Conference.
- The trial evaluated safety, efficacy, and pharmacokinetics in infants and children at risk for severe RSV.
- ENFLONSIA is a monoclonal antibody designed for RSV prevention in high-risk infants.
- The second season results will be shared with the FDA for potential expanded use.
Trial Overview
Merck presented positive findings from the Phase 3 SMART trial at the 9th RSVVW Conference. The trial assessed the safety, efficacy, and pharmacokinetics of ENFLONSIA in infants and children under 2 years at increased risk for severe RSV disease over two RSV seasons.
Key Findings
Results showed that the safety profile of ENFLONSIA in the second RSV season was consistent with the first season. Serum concentrations in high-risk children were similar to those in healthy infants from the Phase 2b/3 CLEVER trial, supporting efficacy extrapolation for children under 2 years.
Regulatory Pathway
The second season results will be shared with the FDA and other global regulatory authorities to evaluate an expanded indication for children at increased risk through their second RSV season. ENFLONSIA is already approved in the U.S., Canada, and several other countries for use in infants during their first RSV season.
Study Details
The SMART trial enrolled infants at increased risk due to prematurity, chronic lung disease, or congenital heart disease. In RSV season 1, participants were randomized to receive either ENFLONSIA or palivizumab. In RSV season 2, eligible participants received an additional open-label dose of ENFLONSIA. The trial demonstrated comparable safety and efficacy between ENFLONSIA and palivizumab, with no drug-related serious adverse events reported.
