Restrictive Palivizumab Use Does Not Lead to Increased Morbidity and Mortality in Pediatric Hematopoietic Stem Cell Transplantation Patients.

Respiratory syncytial virus (RSV) is a common cause of infection in immunocompromised patients and can lead to significant morbidity and mortality in pediatric hematopoietic stem cell transplantation (HSCT) patients and patients with a primary immune deficiency (PID). Palivizumab is a humanized monoclonal antibody that targets the F glycoprotein on the surface of the RSV virus, preventing RSV replication. Palivizumab was initially licensed for the prevention of RSV infections in children at high risk of severe disease. Since licensure, the American Academy of Pediatrics (AAP) has issued guidelines to help ensure appropriate use of palivizumab in pediatric patients. In the 2014 edition of the guidelines, the AAP recognizes that severe and fatal disease secondary to RSV can be seen in patients receiving chemotherapy or patients who are immunocompromised because of other conditions. However, they recognize that no large clinical trials exist to support the use of palivizumab, and efficacy and safety data in this population are limited. Despite this, the AAP recommends considering prophylaxis for children younger than 24 months who are profoundly immunocompromised during the RSV season. Because of the high cost of palivizumab, the uncertainty of its efficacy as prophylaxis in hospitalized pediatric HSCT and PID patients, and secondary to recent data from our center that suggested immunocompromised patients diagnosed with RSV did not have worse outcomes, we implemented very restrictive criteria for the use of palivizumab in the 2015 to 2016 RSV season in our pediatric HSCT population. Despite these strict criteria, there was no change in the number of patients developing RSV during this season compared with previous seasons, and there was no change in RSV course in those patients developing RSV compared with previous seasons. Restricted use also resulted in a significant dose and cost savings. Based on our experience, we recommend only administering prophylaxis palivizumab to the youngest and most high-risk HSCT patients during the RSV season.