Reducing Palivizumab Dose Requirements Through Rational Dose Regimen Design.

Palivizumab for respiratory syncytial virus (RSV) immunoprophylaxis in premature infants poses a significant economic challenge. Although standard dosing of palivizumab results in unnecessary drug accumulation without additional clinical benefit, some clinicians have moved outside of evidence-based practice by implementing untested dose modifications, potentially jeopardizing efficacy. Using an industry-developed population pharmacokinetic model, this study evaluated the previously published alternate dosing regimens and developed a revised regimen that minimizes palivizumab dose requirements while maintaining established therapeutic concentrations. All published dose modifications resulted in unacceptably high proportions of infants not attaining minimum protective concentrations, compromising efficacy. Through intelligent dose regimen design, a clinically practical palivizumab regimen was devised that reduces drug use by 25%, while enabling a greater proportion of infants attaining early season target concentrations, particularly those at greatest risk of the consequences of RSV infection. This novel regimen has the potential to substantially change clinical practice and increase drug availability.