Early response to mepolizumab predicts clinical remission in severe eosinophilic asthma
Published online November 6, 2024
Severe eosinophilic asthma is characterized by high levels of eosinophils, severe symptoms, frequent asthma exacerbations, and dependence on oral corticosteroid (OCS) use. Recent advances in treatment have introduced biologic therapies, such as mepolizumab, a medication that targets IL-5, a key driver of eosinophilic inflammation. Mepolizumab has been shown to improve asthma control, reduce exacerbations, decrease OCS use, and enhance quality of life, with benefits seen as early as three months. A key treatment goal is clinical remission, which has been recently proposed and is defined by well-controlled symptoms, no exacerbations, and no OCS use. Previous studies have shown that up to 30–40% of patients with severe eosinophilic asthma achieve clinical remission within a year of starting mepolizumab. In other chronic inflammatory diseases, including rheumatoid arthritis and inflammatory bowel disease, a treat-to-target approach guides therapy adjustments based on early response to achieve remission. However, it remains unclear whether an early response to mepolizumab can predict clinical remission in severe eosinophilic asthma.
A recent study by Hamada et al., published in The Journal of Allergy and Clinical Immunology: In Practice, investigated whether treatment response at 3 and 6 months could predict clinical remission at 12 months. In this study, clinical remission was defined as having well-controlled asthma symptoms (Asthma Control Questionnaire (ACQ)-5 score ≤1.0) at 12 months, no asthma exacerbations in the previous 6 months, and no OCS use for asthma in the previous 6 months. The authors assessed treatment response using ACQ-5 score, OCS dose, asthma exacerbation frequency, and lung function (post-bronchodilator FEV1). The study analyzed data from 255 patients with severe eosinophilic asthma enrolled in the Australian Mepolizumab Registry, a nationwide, multicenter, prospective, observational registry for the post-marketing surveillance of mepolizumab in severe eosinophilic asthma.
The study found that a prediction model, including ACQ-5 score, exacerbation frequency, OCS dose, and post-bronchodilator FEV1 at 6 months, was more predictive of achieving clinical remission than measures at 3 months. ACQ-5 score at 6 months had the highest predictive value to predict clinical remission at 12 months (area under the curve: 0.778). ACQ-5 score <1.5 at 6 months had a high sensitivity of 85.9% for achieving clinical remission, while ACQ-5 score <0.75 had a high specificity of 84.7%. Overall, ACQ-5 score at 6 months was the best predictor of achieving clinical remission at 12 months in people with severe eosinophilic asthma treated with mepolizumab. These findings suggest that achieving good symptom control at 6 months is important for achieving clinical remission at 12 months. They also support the development of a treat-to-target approach in asthma, where treatment response is assessed at 6 months to predict clinical remission.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.
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