Real-World Corticosteroid-Sparing Effect of Mepolizumab for Severe Asthma

Asian woman using a pressurized cartridge inhaler extended pharynx, Bronchodilator
Can severe asthma be controlled, with less use of corticosteroids, via mepolizumab therapy? An international, real-world study addresses this question.

In patients with severe asthma, real-world treatment with mepolizumab is clinically effective, providing disease control while reducing the need for maintenance oral corticosteroids (mOCS) as well as systemic corticosteroid (SCS) bursts for clinically significant exacerbations. These were among findings of a 1-year analysis of the REALIT- study that were recently published in The Journal of Allergy and Clinical Immunology: In Practice.

Recognizing that the use of mOCS and SCS is associated with adverse effects, which increase patients’ disease burden, researchers for the current study sought to evaluate the real-world corticosteroid-sparing effect of mepolizumab therapy in individuals with severe asthma. To accomplish this, the GlaxoSmithKline REALIT-A cohort study — a 24-month, international, prospective observational study with a 1-year pretreatment and posttreatment preplanned interim analysis — was conducted by investigators in 84 centers in Europe (Belgium, Germany, Italy, Spain, the United Kingdom), Canada, and the US, with the highest percentage of patients recruited from Italy (30%) and the United Kingdom (24%).

The study included 2 cohorts of adult patients (n=822 for treated population; n=823 for control group) with a clinical diagnosis of asthma. Patients in the treatment cohort received mepolizumab 100 mg subcutaneously. The prespecified primary outcome was the rate of clinically significant exacerbations during the pretreatment and follow-up periods. Clinically significant exacerbations were defined as “a deterioration in symptom control requiring use of SCS bursts and/or emergency room (ER) visit and/or hospital admission.” SCS bursts were defined as “OCS for ≥3 days or a single parenteral SCS administration due to worsening of asthma symptoms.”

Other prespecified secondary outcomes evaluated during the pretreatment and follow-up periods included the following: (1) patterns of mepolizumab use, including adherence, duration and discontinuation of treatment, and reasons for treatment discontinuation; (2) rate of patients who experienced exacerbations that required hospitalization or an ER visit, or a hospitalization alone; (3) likelihood of patients experiencing no exacerbations that required hospitalization or an ER visit, or a hospitalization alone; (4) asthma-related health care resource utilization.

Patterns of work status, as measured by Work Productivity and Activity Impairment (WPAI) questionnaire; change in symptom control, as measured by Asthma Control Questionnaire-5 (ACQ-5) score; and total OCS dose were all evaluated between baseline and at every 3 months of the follow-up period.

A total of 319 patients in the treatment cohort received mOCS at baseline (median, 10.0 mg/day; range, 5.0 to 15.0 mg/day). At 1-year posttreatment, the median mOCS dose was decreased by 75% (2.5 mg/day; range, 0.0 to 5.0 mg/day).

Overall, 64% of treatment cohort participants experienced a reduction in mOCS dose of ≥50% compared with baseline, and 43% discontinued mOCS. Clinically significant exacerbations decreased significantly between the pretreatment and the posttreatment period (rate ratio, 0.29; 95% CI, 0.26-0.32; P <.001).

Limitations of the REALIT-A study include its single-arm, open-label design, which results in a lack of comparator for unblended mepolizumab therapy. Further, because the majority of patients enrolled in the study were from Western Europe, the study population may not be truly representative of the global population of those with severe asthma.

The researchers concluded that “these findings highlight the SCS-sparing potential of mepolizumab in patients with severe asthma who require SCS bursts and/or mOCS and may help guide physicians and specialists to make informed treatment decisions for their patients.”

Disclosure: This research was funded by GlaxoSmithKline. Some study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures. 


Pilette C, Canonica GW, Chaudhuri R, et al. REALITI-A study: real-world oral corticosteroid-sparing effect of mepolizumab in severe asthma. J Allergy Clin Immunol Pract. Published online June 23, 2022. doi:10.1016/j.jaip.2022.05.042