Omalizumab Reduces Asthma Exacerbations Across Airway Reversibility Subgroups

HOUSTON — Treatment with omalizumab may reduce exacerbations of asthma in patients categorized into several different airway reversibility subgroups based on forced vital capacity (FVC) or forced expiratory volume in 1 second (FEV₁). These findings were presented at the American College of Allergy, Asthma, & Immunology Annual Scientific Meeting 2019 held November 7 to 11 in Houston, Texas.

According to investigators, the effect of airway reversibility on exacerbations of asthma is not well understood. Despite this paucity of information, airway reversibility does have a well-understood and established effect on lung function improvement. Omalizumab, a recombinant DNA-derived humanized immunoglobulin G1k monoclonal antibody, can reduce asthma exacerbations in patients with inadequately controlled disease.

Adult patients with asthma (n=710) who were treated with omalizumab in the 48-week, single-arm PROSPERO study (ClinicalTrials.gov Identifier: NCT01922037) were included in this analysis. Only patients who had available baseline airway reversibility data were included. The researchers examined the estimated exacerbation rates normalized by omalizumab duration and the 3 baseline airway reversibility subgroups. These baseline reversibility subgroups were ≤12%, >12% to ≤20%, and >20% in FVC or the FEV₁.

Patients with >20% reversibility were a younger mean age (50.4 vs 53.2 vs 47.9 years), had slightly higher blood eosinophil levels (284.5 vs 317.3 vs 326.6 cells/L), and had worse lung function (78.7 vs 65.8 vs 54.6% predicted FEV₁) compared with the patients with ≤12% and >12% to ≤20% reversibility, respectively.

All patients had asthma exacerbations in the year prior to enrollment, with a mean number between 2.8 and 3.6. The adjusted exacerbation rate after receiving omalizumab in the ≤12% subgroup was 0.7 (95% CI, 0.6-0.8). In the >12 to ≤20% subgroup, the posttreatment adjusted exacerbation rate was 0.9 (95% CI, 0.7-1.3). The >20% reversibility subgroup featured a 1.1 (95% CI, 0.8-1.5) adjusted exacerbation rate after treatment with omalizumab. The researchers found no new safety signals in this analysis of the PROSPERO trial.

Limitations of this study include its secondary, retrospective nature of PROSPERO as well as the trial’s single-arm design.

Reference

DeLeon S, Barsanti F, Haselkorn T, Yoo B, Creasy B, Wechsler M. Asthma exacerbation reduction in adults with high/low airway reversibility following omalizumab treatment: results from PROSPERO. Presented at: American College of Allergy, Asthma, & Immunology Annual Scientific Meeting 2019; November 7-11, 2019; Houston, TX. Abstract 227.