Antibodies | Blood Eosinophil Decrease After Mepolizumab Treatment Predicts Clinical Remission in Severe Asthma Patients

This study systematically evaluated the association between blood eosinophil level changes and treatment response to Mepolizumab in real-world settings for the first time. It demonstrates that a >90% reduction in blood eosinophils effectively predicts clinical remission with high specificity, providing a potential biomarker for long-term management of severe asthma.

 

Literature Overview
This article 'Mepolizumab-Related Blood Eosinophil Decreases Are Associated with Clinical Remission in Severe Asthmatic Patients: A Real-World Study', published in the journal Antibodies, reviews a real-world study involving 58 severe asthma patients treated with Mepolizumab. The research investigates the relationship between early eosinophil reduction during treatment and clinical remission after two years, revealing that significant eosinophil decline serves as a predictive biomarker for remission.

Background Knowledge
Severe eosinophilic asthma represents a distinct asthma subtype characterized by persistently elevated blood eosinophil levels. Mepolizumab, a humanized monoclonal antibody targeting IL-5, reduces eosinophil levels by blocking IL-5 receptor binding, thereby improving asthma control. While randomized controlled trials (RCTs) have confirmed Mepolizumab's efficacy, its long-term effectiveness and biomarker predictive value in real-world clinical practice remain uncertain. Additionally, no definitive conclusions exist regarding the dynamic correlation between eosinophil levels as a biomarker and clinical remission. This study represents the first systematic real-world assessment of blood eosinophil changes as a potential predictor for long-term Mepolizumab efficacy, exploring its application value in clinical management.

 

 

Research Methods and Experiments
This retrospective cohort study included 58 severe eosinophilic asthma patients receiving Mepolizumab treatment. All patients underwent asthma control testing (ACT scores), pulmonary function assessments (FVC and FEV1), exacerbation frequency monitoring, and maintenance therapy evaluation before treatment (T0) and after two years of treatment (T2). Blood eosinophil counts were recorded at baseline (T0) and after one year of treatment (T1), with relative changes calculated as ΔEOS%. Non-parametric statistical methods were employed to evaluate correlations between clinical outcomes and eosinophil dynamics, while multivariable logistic regression analysis identified independent predictive factors.

Key Conclusions and Perspectives

• After two years of Mepolizumab treatment, patients demonstrated significant improvements in ACT scores, FVC, and FEV1, alongside substantial reductions in exacerbation frequency and maintenance therapy requirements.
• Greater pulmonary function improvement and exacerbation frequency reduction correlated with lower eosinophil counts (EOST1) observed after the first treatment year.
• Relative eosinophil change from baseline to year one (ΔEOS%) serves as an independent predictor for clinical remission, with ΔEOS% ≥ -90% predicting clinical remission at 80% specificity.
• Despite pronounced early treatment-induced eosinophil reduction, baseline eosinophil levels showed no significant correlation with long-term clinical remission.

Research Significance and Prospects
This study provides the first real-world evidence establishing blood eosinophil reduction as a potential biomarker for long-term Mepolizumab efficacy. Future research should standardize blood sample collection timelines to further validate this marker's predictive value, while exploring its applicability in other anti-IL-5 or anti-IL-5R therapies.

 

 

Conclusion
Our findings demonstrate that significant early eosinophil reduction during Mepolizumab treatment effectively predicts long-term clinical remission in severe asthma patients. While demonstrating lower sensitivity, the 80% specificity highlights its clinical guidance potential in real-world practice. Future studies should standardize eosinophil monitoring protocols and validate these findings in larger cohorts. These results may also inform personalized treatment decisions for other eosinophil-targeted biologics.

 

Matteo Bonato, Francesca Savoia, Enrico Orzes, Gianenrico Senna, and Micaela Romagnoli. Mepolizumab-Related Blood Eosinophil Decreases Are Associated with Clinical Remission in Severe Asthmatic Patients: A Real-World Study. Antibodies.