FDA Announced Review of RSV Treatments Concerns PIDS

The Pediatric Infectious Diseases Society is concerned by the U.S. Food and Drug Administration announcing it will open an unprompted safety review of respiratory syncytial virus treatments nirsevimab and clesrovimab. These RSV-specific monoclonal antibodies were approved by FDA after evaluation in thousands of children in placebo-controlled clinical trials, during which no concerning safety signals were identified, nor have there been since the Centers for Disease Control and Prevention’s 2023 recommendation.  

Prior to the availability of RSV-specific antibody therapies, pediatricians had limited options to prevent severe infections among infants, who bear the greatest risk of severe RSV disease. In the U.S. alone, RSV causes approximately 80,000 hospitalizations and 300 deaths each year in children under 5 years of age. RSV hospitalizations in infants under 8 months of age have decreased by 43% since the introduction of nirsevimab and clesrovimab (as well as maternal RSV immunization for some infants). The greatest reductions have been observed in infants under 3 months old, with declines as high as 71% in this most vulnerable group.

PIDS strongly supports continued post-licensure safety monitoring using the robust U.S. safety surveillance systems that have been in place for decades. To date, both nirsevimab and clesrovimab continue to be well tolerated, safe and effective. In the absence of evidence indicating otherwise, the FDA’s recent announcement is unusual and risks generating unnecessary doubt among parents.

Any efforts to restrict access to these medications without supporting evidence would unequivocally threaten vulnerable infants and deny families the opportunity to protect their children from severe RSV disease.