Real-world Data Showed Mepolizumab Reduced Exacerbations, Oral Corticosteroid Use in Adults with Severe Asthma

ATS 2022

ATS 2022: Mepolizumab was effective in reducing asthma exacerbations and oral corticosteroid use in real-world clinical practice, according to new research.

Mepolizumab was effective in reducing clinically significant asthma exacerbations (CSEs) and oral corticosteroid (OCS) use in real-world clinical practice, according to an interim analysis of the international REALITI-A clinical trial.

Findings were presented at American Thoracic Society’s (ATS) International Conference 2022, held May 13-18 live in San Francisco and online.

In several phase 3 studies, mepolizumab treatment has been found to reduce CSEs and OCS use and improve asthma control in patients with severe eosinophilic asthma. Although these findings have been mirrored in several regional real-world studies, “differences in their study designs confounds national comparisons,” wrote study authors.

To investigate the use of mepolizumab across different nations, researchers analyzed data from REALITI-A, a 2-year prospective, observational study. Adults with asthma were enrolled in the study following a physician decision to initiate mepolizumab treatment (100mg subcutaneous). Participants were recruited at centers in Belgium, Canada, Germany, Italy, Spain, the United Kingdom, and the US.

The primary endpoint was the rate of CSEs (requiring systemic corticosteroids and/or hospital/emergency room admission) following mepolizumab treatment compared to the 12-month pre-treatment period. Secondary endpoints included change from baseline (28 days preceding mepolizumab treatment) in maintenance OCS (mOCS) dose during follow-up.

The current interim analysis included the full study population at 1 year, stratified by recruiting countries.


Investigators found that, before mepolizumab treatment, patients in the UK and Spain had the highest mean CSE events per year. Participants from all countries had a 62%-82% reduction in the rate of CSEs during follow-up compared with pre-treatment, with Italy and Spain having the greatest relative reductions.

At baseline, participants in the UK, Spain, and Germany had the highest mOCS use; those in the UK, USA, and Spain had the highest median daily mOCS dose (10 mg/day), according to the study abstract.

A reduction in median daily mOCS dose was observed in all countries at week 53-56 vs baseline; patients from Italy, Spain, and the US had a median mOCS dose of 0.0mg/day at week 53-56. The highest proportion of patients who discontinued mOCS use by week 53-56 was from the US, Italy, and Spain, while the lowest proportion was in the UK where the OCS burden at baseline was greatest.

“Our findings extend clinical trial data and highlight that mepolizumab was effective in reducing CSEs and mOCS use in real-world clinical practice across multiple nations in patients with severe eosinophilic asthma. Variability in our study outcomes across the nations may be due to different baseline characteristics, driven by healthcare policies,” concluded study authors.

Reference: Lee JK, Schleich F, Canonica GW, et al. National differences in real-world outcomes with mepolizumab treatment for patients with severe asthma: Results from the REALITI-A study. Abstract presented at: The ATS International Conference; May 13-18, 2022; San Francisco, CA. Abstract available at: