Effect of Delayed Initiation of Mepolizumab on EXACTO Scale Scores, Clinical Remission SEPAR-REMAS Criteria, and Functional Outcomes in Uncontrolled Severe Asthma: A Real-World Study

Introduction

Delayed initiation of mepolizumab may influence long-term disease control and the achievement of clinical and functional outcomes in patients with uncontrolled severe asthma (SUA), but no definitive conclusions have yet been established regarding the optimal timing for biologic initiation. The aim of this study was to evaluate, in a real-world clinical setting, the effect of delayed mepolizumab initiation—from the moment patients first met EMA eligibility criteria—on the treatment response (using the EXACTO scale), clinical remission (according to SEPAR-REMAS criteria) and lung function at 12 months and 3 years after treatment initiation. Material and Methods: We conducted a retrospective observational cohort study including 148 patients with SUA treated with mepolizumab from January 2017 to November 2024 in our hospital. Patients were stratified into tertiles according to delay: ≤5 months, 6–19 months, and >19 months. Baseline demographic, clinical, and lung function characteristics were analyzed.