Omalizumab Effective in Severe Allergic Asthma, Regardless of Eosinophil Level

Eosinophil cells
Eosinophil cells
Regardless of blood eosinophil count, omalizumab was an effective treatment in adult and pediatric patients with severe allergic asthma.

In patients with severe allergic asthma (SAA), omalizumab was an effective treatment option irrespective of blood eosinophil count (EOS), according to the results of the French STELLAIR study published in the European Respiratory Journal.

Marc Humbert MD, PhD, of the Université Paris-Sud, Faculté de Médecine, Université Paris-Saclay in Le Kremlin Bicêtre, France, and colleagues conducted a retrospective, real-life study between December 2015 and September 2016 using the medical records of patients with SAA who were treated with omalizumab. They assessed response to omalizumab using 3 criteria: physician evaluation, reduction of ≥40% in annual exacerbation rate, and a combination of both. Response rate was calculated according to EOS measured in the year prior to omalizumab initiation.

The study included 872 patients (723 adults and 149 minors aged 6 to 17 years) and 78 physicians. EOS was ≥300/μL in 52.1% of adults and in 73.8% of minors. The physicians determined that 67.2% of adults and 77.2% of minors were responders, and 71.1% of adults and 78.5% of minors had a 40% reduction in the exacerbation rate. For the combined criteria, the adult response rate was 58.5% (95% CI, 53.2%-63.4%) in those with EOS ≥300 and 58.1% (95% CI, 52.7%-63.4%) in those with EOS <300. These results suggest that the effectiveness of omalizumab is similar in high and low EOS subgroups.

The study was limited by its retrospective design; however, the findings for both adults and minors were similar to the results of previous studies conducted during clinical development and in real-life settings. The STELLAIR study bears out the differences between severe asthma in adults and minors: adults are more often female (60.9%) vs minors, who are more often male (63.1%).

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The authors suggested that the results of this study can be generalized to patients with SAA eligible for omalizumab and managed by pulmonologists and pediatricians in France. They called for prospective studies to assess the clinical effectiveness of biologics targeting overlapping populations of patients with SAA and high blood EOS.


Humbert M, Taillé C, Mala L, Le Gros V, Just J, Molimard M. Omalizumab effectiveness in patients with severe allergic asthma according to blood eosinophil count: the STELLAIR study [published online March 15, 2018]. Eur Respir J. doi:10.1183/13993003.02523-2017