Mepolizumab real-world effectiveness in severe asthma with an eosinophilic phenotype and overlapping severe allergic asthma

Abstract

Background

Some patients with severe asthma have overlapping allergic and eosinophilic phenotypes and may be eligible for anti-eosinophilic or anti-immunoglobin E (IgE) biologics.

Objective

This post hoc sub-analysis assessed real-world mepolizumab effectiveness in patients with overlapping allergic and eosinophilic phenotypes, using 1-year data from the international, prospective REALITI-A (REAL world effectiveness of mepolizumab In paTIent care – Asthma) study.

Methods

The clinically significant asthma exacerbations (CSE) rate was assessed 1 year before (pretreatment) and after (follow-up) mepolizumab treatment, stratified by baseline total IgE (tIgE) levels (<60, 60 to <190, 190 to <550, and ≥550 kilounits per litre [kU/L]), atopic status (yes/no/unknown), previous omalizumab use (yes/no), geographic baseline omalizumab eligibility (eligible/non-eligible), and baseline tIgE level and blood eosinophil count threshold combinations (<81 or ≥81 kU/L and <300 or ≥300 cells per microliter [cells/μL]).

Results

Overall, 822 patients were included. CSEs occurred in 760 patients (93%) pretreatment and 398 patients (49%) during follow-up. CSE rate (rate ratio [95% CI]) was reduced in follow-up across all tIgE subgroups (<60 [n = 173]: 0.31 [0.25-0.37]; 60 to <190 [n = 176]: 0.30 [0.25-0.36]; 190 to <550 [n = 170]: 0.26 [0.20-0.33]; ≥550 kU/L [n = 155]: 0.28 [0.23-0.35]) and irrespective of atopic status (yes [n = 422]: 0.29 [0.26-0.33]; no [n = 52]: 0.33 [0.23-0.47]; unknown [n = 348]: 0.28 [0.24-0.32]), previous omalizumab use (yes [n = 151]: 0.37 [0.30-0.45]; no [n = 671]: 0.27 [0.24-0.30]), or eligibility (eligible [n = 349]: 0.29 [0.25-0.34]; non-eligible [n = 191]: 0.32 [0.27-0.38]). Furthermore, the CSE rate was reduced across all tIgE (kU/L) and blood eosinophil count (cells/μL) combinations (<81/<300 [n = 53]: 0.34 [0.24-0.47]; <81/≥300 [n = 103]: 0.33 [0.26-0.41]; ≥81/<300 [n = 98]: 0.36 [0.28-0.47]; ≥81/≥300 [n = 249]: 0.26 [0.22-0.31]).

Conclusion

Mepolizumab demonstrates real-world effectiveness in reducing exacerbations in patients with severe asthma and an eosinophilic phenotype, regardless of any overlapping allergic phenotype.