Population Pharmacokinetics of Clesrovimabin Preterm and Full-Term Infants

In this study published in Clinical Pharmacology & Therapeutics (CPT), researchers addressed the challenge of protecting infants from respiratory syncytial virus (RSV), a leading cause of hospitalization worldwide, across a highly diverse population of preterm and full-term infants. Because effective RSV prevention must provide consistent protection throughout an entire season, the key problem was determining whether a simple, single-dose strategy could work despite differences in infant size, age, and medical risk.

Using data from nearly 3,000 infants enrolled in three clinical trials, the authors developed a population pharmacokinetic (PopPK) model for clesrovimab, a long-acting monoclonal antibody against RSV. The analysis showed that clesrovimab remains in the body for an extended period and that factors such as body weight, age, and race had only small effects on drug exposure. Overall, the findings support a single intramuscular dose once per RSV season for all infants, including those at higher risk, and demonstrate how quantitative pharmacology can translate complex clinical data into a practical, scalable prevention strategy.