Possible Protective Effect of Omalizumab on Lung Function Decline in Patients Experiencing Asthma Exacerbations

Background Frequent exacerbations are associated with greater FEV1 decline in patients with asthma. The effect of omalizumab versus placebo on lung function in patients experiencing asthma exacerbations has not been previously examined. Objective To evaluate the relationship between postbaseline (treatment phase) exacerbation status and lung function decline in children, adolescents, and adults treated with omalizumab versus placebo using data from 3 pediatric and adolescent/adult studies. Methods Changes in percent predicted FEV1 (ppFEV1) and FEV1 by treatment (omalizumab/placebo) and postbaseline exacerbation status (exacerbators/nonexacerbators) were assessed in patients aged 6 to 11 years (IA05, n = 576) and 12 to 75 years (EXTRA/INNOVATE pooled, n = 1202). Pediatric patients were examined at treatment weeks 12, 24, 28, 40, and 52, and adolescent/adult data at weeks 4, 12, 20, and 28. Results Omalizumab-treated patients experienced larger increases in ppFEV1 and FEV1 compared with placebo-treated patients in the pediatric and pooled adolescent/adult populations. The response was observed in pediatric exacerbators, with significantly larger increases in ppFEV1 and FEV1 at week 12 (mean difference [95% CI], 4.11% [0.93%-7.30%], P = .011 for ppFEV1; 80 [10-140] mL, P = .017 for FEV1) and week 28 (mean difference [95% CI], 3.65% [0.11%-7.19%], P = .043 for ppFEV1; 100 [30-170] mL, P = .007 for FEV1). In the adolescent/adult population, both exacerbators and nonexacerbators derived similar benefit with omalizumab compared with placebo. Conclusions Findings from this post hoc analysis suggest that omalizumab may confer some protection against lung function decline among patients who experienced exacerbations during treatment.