A real-world study to evaluate effectiveness of mepolizumab in treating severe asthma in Taiwan (REMIT).

Background: REMIT is the first real-world study of mepolizumab effectiveness in patients with severe asthma (SA) in Taiwan.

Objectives: The primary objective evaluated changes in clinically significant exacerbations (CSEs; defined as use of oral corticosteroids (OCS) or emergency department (ED) visits and/or hospitalizations) in the 12 months pre- and post-mepolizumab treatment. Secondary objectives assessed changes in the number of CSEs requiring ED visits/hospitalizations and daily maintenance OCS (mOCS) dosage 12 months pre- and post-mepolizumab treatment. Three- and four-component clinical remissions were analyzed based on OCS-free, exacerbation-free, and asthma control (± stability in lung function).

Design: REMIT was a retrospective, observational, self-controlled study analyzing patients in Taiwan with SA who were newly prescribed subcutaneous mepolizumab 100 mg Q4W.

Methods: Data were extracted from records of 15 medical centers in Taiwan for patients indexed between November 1, 2018 and October 31, 2020.

Results: A total of 170 patients were included: mean age at index date, 58.7 years; 53.5% female; 100% Chinese; 7.1% with chronic rhinosinusitis with nasal polyps, 1.8% with eosinophilic granulomatosis with polyangiitis, 1.2% with hypereosinophilic syndrome; and 55.7% with blood eosinophil count >300/µL. Pre-treatment, 71.2% had ⩾2 exacerbations, and 28.7% were on mOCS; 75.3% had no prior biologic treatment, and 24.7% had switched from other biologics. Most patients (80.0%) completed ⩾10 mepolizumab doses. Following the first mepolizumab administration (index date), CSEs reduced by 46.0% (rate ratio (RR): 0.545, 95% confidence interval (CI): 0.418-0.710;  < 0.0001) in the 12 months post-index. Exacerbations requiring ED visits/hospitalization reduced by 46.9% (RR: 0.531, 95% CI: 0.349-0.808;  = 0.0031). Median mOCS dose reduced by 100% by end of study and 81.8% of patients discontinued mOCS post-treatment. After 1 year of mepolizumab treatment, 28% and 23% patients achieved three- and four-component clinical remission, respectively.

Conclusion: Mepolizumab use in a patient population in Taiwan with SA significantly reduced CSEs and mOCS use in routine clinical practice.