palivizumab for RSV

Tis the season. We spend a lot of time and money getting Synagis (Polivizumab) for our most at-risk patients. How much benefit is there to be gained here?

Two trials, one from the IMpact-RSV Study Group published in Pediatrics in September of 1998, and one from the Cardiac Synagis Study Group, lead author, our own Timothy Feltes, established the role of polivizumab in preventing morbidity in high risk pediatric populations.

1. IMpact-RSV trial Cliff's Notes

• Palivizumab is a humanized mouse monoclonal IgG antibody against the F protein of RSV.

• In the study, 15 mg/kg IM polivizumab or placebo was administered monthly for 5 months to infants with GA less than or equal to 35 weeks who were <6 mos of age or infants <24 mos with BPD.
  

• It was double blinded and placebo controlled.

• They showed a 55% reduction in hospitalizations for all comers.

• For premature infants, this reduction was 78%, and for the BPD group it was 39%.

2. Feltes paper Cliff's Notes

• Congenital Heart disease had been excluded from the original polivizumab studies.

• The last drug for RSV (RSV-IGIV) had increased mortality in congenital heart disease patients.

• This was hypothesized to be secondary to increased viscosity.

• Study patients were hemodynamically significant CHD patients <24>

• This was a double blinded placebo controlled trial.

• Relative reduction in rate of hospitalization of 45% was shown in the polivizumab group.

• Duration of hospitalization and duration of oxygen therapy during hospitalization were also shown.

• No associated adverse events were noted.