Mepolizumab Clinically Effective Regardless of Type 2 Biomarker Status in Patients with Severe Asthma, Suggests Real-world Data

Results from 2 real-world studies demonstrate that when used by physicians, mepolizumab is effective in standard clinical care regardless of type 2 eosinophil biomarker status in patients with severe asthma.

Mepolizumab is an anti-IL-5 monoclonal antibody used in the treatment of eosinophilic severe asthma.

“The mepolizumab RCTs in severe asthma suggested a baseline blood eosinophil threshold of 150 cells/µL to identify responders for beneficial exacerbation reduction response,” wrote authors of the study abstract presented at the 2022 annual meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI), February 25-28, 2022.

Two real-world experience data sets were used to evaluate the applicability of a blood eosinophil threshold of 150 cells/µL: REALITI-A, a prospective international database study (n=822) and REDES, a retrospective national database study (n=318). Both studies were observational and included adults with severe asthma in whom a physician had initiated treatment with mepolizumab 100 mg subcutaneous.

The primary endpoint was the rate of clinically significant asthma exacerbations (CSE)—defined for the purpose of the study as requiring the use of systemic corticosteroids or hospital or emergency department admission—between the 12 months before and after mepolizumab treatment started.

Researchers evaluated CSE reduction in the year after mepolizumab was initiated in relationship to categories of progressively increasing baseline pre-treatment blood eosinophil counts (cells/µL) with ranges from <150 to ≥500 in REALITI-A and <150 to ≥700 in REDES.

According to the results, treatment with mepolizumab significantly reduced total CSE in REALITI-A (71%) and REDES (77.5%) from respective mean pretreatment annual rates of 4.28 and 4.48. This decrease was observed across the spectrum of baseline blood eosinophil levels in both studies.

“These real-world studies identify that mepolizumab, as used by physicians, is effective in standard clinical care irrespective of type 2 eosinophil biomarker status (high or low) in patients with severe asthma,” concluded study authors.