On 19 May, at the 2025 American Thoracic Society (ATS) International Conference, a poster session by researchers from Ghent University Hospital presented real-world evidence showing that anti–IL-5 biologics significantly reduce both moderate and severe exacerbations in patients with obstructive lung disease, including those with coexisting asthma and chronic obstructive pulmonary disease (COPD). This retrospective analysis, based on Belgian national claims data, highlights the effectiveness of biologics such as mepolizumab and benralizumab across diverse patient subgroups beyond those typically enrolled in controlled trials.
The study evaluated 807 adults who initiated an anti–IL–5 therapy (79% mepolizumab, 21% benralizumab) between 2017 and 2020. Among them, 191 patients had diagnoses of both asthma and COPD. Exacerbation rates in the year before and after therapy initiation were compared, with events categorised as severe (hospitalisations) or moderate (treated with antibiotics [AB], oral corticosteroids [OCS], or both).
Severe exacerbations declined from 40 to 17 events per 100 patient-years post-treatment (p<0.001), corresponding to a 56% relative risk reduction (RRR) and a number needed to treat (NNT) of 4. Patients with both asthma and COPD experienced the greatest absolute benefit, with hospitalisations falling from 119 to 53 events per 100 patient-years (RRR 55%, NNT=2). In contrast, asthma-only patients saw a reduction from 15 to 6 events (NNT=11), reflecting the higher baseline burden in those with coexisting disease and the potential for biologics to significantly offset costly care utilisation.
Moderate exacerbations also improved across most categories. In asthma-only patients, AB-only events declined by 18%, and OCS + AB events dropped by 41%. Among those with both asthma and COPD, AB-only events fell 20%, and OCS + AB events were reduced by 21%. However, OCS-only exacerbations did not improve significantly in this subgroup (p=0.288), particularly among current smokers, where the anti–IL–5 therapy was less effective in reducing corticosteroid use, but still resulted in substantial reductions in hospitalisations (RRR 64%, NNT=1).
These improvements occurred across a real-world population with a wide range of comorbidities and disease profiles, reinforcing the role of eosinophilic inflammation as a treatment-guiding biomarker. The findings underscore the value of biologics not only in reducing symptom burden but also in alleviating systemic healthcare strain by preventing hospital-based care.
From a commercial standpoint, the data adds weight to the use of anti–IL–5 biologics in patient groups beyond those with classical severe eosinophilic asthma. With hospitalisations driving a substantial portion of healthcare costs in patients with coexisting asthma and COPD, biologics that can effectively prevent inpatient admissions are well-positioned to secure favourable payer evaluations, especially in cost-conscious European markets. These real-world outcomes may also support health economic submissions and label expansion efforts in jurisdictions where COPD remains an off-label indication.
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By GlobalDataKey opinion leaders interviewed by GlobalData consistently highlight the value of mechanism-specific targeting in eosinophilic inflammation. Many view anti–IL–5 therapy as a more focused and predictable approach for patients with persistent blood eosinophilia, especially those who continue to exacerbate despite inhaled triple therapy. Some KOLs note that while upstream agents like anti–IL–4R may benefit broader inflammatory profiles, IL-5 inhibitors remain the preferred choice in cases where eosinophil-driven exacerbations are predominant and frequent.
With an increasingly competitive respiratory biologics landscape, real-world differentiation will likely focus on hospitalisation prevention, biomarker precision, and tolerability in patients with overlapping chronic lung disease. The Belgian dataset provides supportive evidence that mepolizumab and benralizumab can deliver meaningful outcomes in these high-need populations, positioning them as versatile tools in a stepwise, phenotype-driven treatment paradigm.
