Response to Omalizumab in Black and White Patients with Allergic Asthma

Higher asthma burden is more likely to be experienced by Black than White patients. In clinical research, underrepresentation of minority populations is observed.

To estimate response to omalizumab in Black and White patients in North America with moderate to severe asthma.

Data from placebo-controlled (EXTRA) and single-armed (PROSPERO) omalizumab studies were used for this post hoc analysis. We used a Poisson regression model to examine exacerbation rates. An analysis of covariance model was used to estimate placebo-corrected change in FEV₁ and Asthma Quality of Life Questionnaire (AQLQ) by racial group.

This analysis included 631 White and 176 Black patients from EXTRA and 567 White and 130 Black patients from PROSPERO. In EXTRA, placebo-corrected exacerbation rate reductions (relative rate change [95% confidence interval], 22.6% [2.0-38.9%] vs 22.0% [-18.0% to 48.4%]) and FEV₁ improvements were similar for White and Black patients. There was a trend toward greater AQLQ improvements for Black versus White patients (least squares mean treatment differences: 0.0 vs 0.3, 0.6 vs 0.4, and 0.6 vs 0.2 at weeks 16, 32, and 48, respectively) throughout the study. In PROSPERO, on-study exacerbation rates (0.76 [0.65-0.88] vs 0.77 [0.56-1.10]) and AQLQ improvements (least squares mean change from baseline: 1.2 vs 1.2 and 1.3 vs 1.2 at month 6 and end of study, respectively) were similar for White versus Black patients. A trend toward greater FEV₁ improvement was observed in White versus Black patients throughout the study.

This analysis of EXTRA and PROSPERO suggests that Black and White patients with moderate to severe asthma experience similar improvements in exacerbations, FEV₁, and AQLQ with omalizumab.