Adherence and outcomes: a systematic review of palivizumab utilization.

INTRODUCTION: Palivizumab is a humanized monoclonal antibody used for respiratory syncytial virus (RSV) prophylaxis. RSV is the primary cause of lower respiratory tract infection in children aged <2 years, and can give rise to high-burden hospitalization and respiratory complications in later life. Adherence to a monthly dosing regimen, both in timing and injection number, is essential to sustain therapeutic levels of palivizumab and maintain protective status. Deviation from the approved dosing schedule may reduce the efficacy of palivizumab and increase the risk of breakthrough RSV infection and hospitalization. Areas covered: There is no standardized definition of adherence to palivizumab treatment. This review addresses the wide variability in defining and reporting adherence to palivizumab prophylaxis across different studies. The review assesses whether a relationship exists in the outcomes reported in studies relative to the monthly adherence protocol as defined in published randomized controlled trials of the efficacy and safety of palivizumab. Expert commentary: Standardized detailed reporting of adherence to palivizumab prophylaxis using consistent definitions will help provide a more robust level of evidence. This information may be important when considering variations in effectiveness, alterations to recommendations and guidelines, and cost-effectiveness of treatment.