Palivizumab and long-term outcomes in cystic fibrosis

BACKGROUND: The American Academy of Pediatrics does not recommend routine use of palivizumab prophylaxis for infants with cystic fibrosis (CF) but recommends consideration in infants with clinical evidence of chronic lung disease or nutritional compromise. However, the beneficial impact of palivizumab on longer-term outcomes is uncertain. METHODS: We used Cystic Fibrosis Foundation Patient Registry data to assess the association of receiving palivizumab during the first 2 years of life with longer-term outcomes, including lung function at 7 years old, time to first positive Pseudomonas respiratory culture, and pulmonary-related hospitalizations during the first 7 years of life. Eligible infants were born from 2008 to 2015 and diagnosed with CF during the first 6 months of life. Demographic and clinical confounders of association between palivizumab receipt and outcomes were explored. We created propensity scores to adjust for potential confounding by indication (ie, sicker infants were more likely to receive palivizumab). For each outcome, we performed regression analyses adjusted by propensity scores. RESULTS: The sample included 4267 infants; 1588 (37%) received palivizumab. Mean percent forced expiratory volume in 1 second predicted at 7 years old was similar among those who did (98.2; 95% confidence interval: 96.9-99.5) and did not (97.3; 95% confidence interval: 96.1-98.5) received palivizumab, adjusting for propensity scores. Time to first positive Pseudomonas aeruginosa culture and annual risk of hospitalization were similar among those who did and did not receive palivizumab. CONCLUSIONS: At the population level, palivizumab receipt was not associated with improved longer-term outcomes in children with CF.