Clesrovimab in prevention of RSV lower respiratory tract disease: a profile of its use in infants

Clesrovimab (ENFLONSIATM, clesrovimab-cfor), a long-acting monoclonal antibody that targets the respiratory syncytial virus (RSV) fusion protein, is a useful addition to prophylactic options for RSV-associated lower respiratory tract (LRT) disease in neonates and infants born during or entering their first RSV season. As demonstrated in the phase 2b/3 CLEVER clinical trial, a single 105 mg dose of clesrovimab, irrespective of body weight, provides durable protection against RSV-associated medically-attended lower respiratory infection (RSV-MALRI), and reduces RSV-associated hospitalizations in neonates and infants born during or entering their first RSV season. Pharmacokinetic data from the phase 3 SMART trial supports the efficacy of clesrovimab in infants and children at increased risk of severe RSV disease. Clesrovimab was generally well tolerated, with low reactogenicity, and had a similar adverse event profile to placebo (CLEVER) and palivizumab (SMART). Respiratory syncytial virus (RSV) is a significant cause of infant hospitalizations and deaths. Clesrovimab (ENFLONSIATM), a novel long-acting monoclonal antibody (mAb) that binds a highly conserved site on the RSV fusion protein, was recently approved in the USA and the EU for the prevention of RSV-associated lower respiratory tract (LRT) disease in neonates and infants born during or entering their first RSV season. As demonstrated in clinical trials, clesrovimab, administered as a single 105 mg dose regardless of body weight, provides durable protection against RSV disease in neonates and infants born during or entering their first RSV season. Data from a phase 3 clinical trial supports the efficacy of clesrovimab in infants and children aged < 2 years at increased risk of severe RSV disease. Clesrovimab is well tolerated, with low rates of adverse events. As the second long-acting mAb approved for prevention of RSV disease, clesrovimab represents a useful addition to treatment options for neonates and infants born during or entering their first RSV season.