Greater Treatment Benefit with Omalizumab in Children with Increased Asthma Severity: Exploratory Analyses from the Inner-City Anti-IgE Therapy for Asthma (ICATA) Study

RATIONALE: Post hoc analyses at 24 weeks from a randomized trial in children ages ≥6 to <12 years with moderate-to-severe persistent allergic asthma (Lanier et al., 2009) showed significantly greater response to omalizumab versus placebo for exacerbation reduction among subgroups of children with increased asthma severity. We extended findings in post hoc analyses from a randomized trial of inner-city children ages 6 to 20 years with moderate-to-severe persistent allergic asthma.

METHODS: Poisson regression analysis examined exacerbation rate reduction for omalizumab versus placebo at 56 weeks in the Inner-City Anti-IgE Therapy for Asthma (ICATA) Study. Children ages ≥6 to <12 years (n=237) were stratified by baseline percent predicted pre-bronchodilator FEV₁ (ppFEV₁) (<90%, ≥90%) and any hospitalization in the prior 6 months. Exacerbations were defined as those requiring systemic glucocorticoids, hospitalization, or both.

RESULTS: Baseline demographics were similar between treatment groups and across strata. Mean (SD) age ranged between 8.1 (1.7) and 8.7 (1.7) years. Exacerbation rates were reduced by the following percentages (95% CI, p-value) for omalizumab versus placebo: ppFEV₁<90%, 36% (0, 59; p=0.05) and ≥90%, 18% (-29, 48; p=0.39); hospitalization in prior 6 months: Yes, 46% (4, 70; p=0.04), and No, 24% (-10, 48; p=0.15).

CONCLUSIONS: Post hoc findings from ICATA and the Lanier et al. pediatric trial are consistent, showing significantly greater response to omalizumab for exacerbation reduction among children with increased asthma severity, defined by ppFEV₁<90% or hospitalization in the prior 6 months. Exacerbation reductions were observed for ppFEV₁≥90% or no hospitalization in the prior 6 months, but were not statistically significant.