The Influence of Emphysema on Treatment Response to Biologic Therapy in Severe Asthma

Patients with severe asthma (SA) benefit from biologic therapy substantially. However, the impact of smoking-related comorbidities remains unclear due to the exclusion of patients with ≥10 pack-years from asthma studies. Our aim was to examine the effects of emphysema on biologic treatment response in SA in this retrospective cohort study.

Pulmonary emphysema was examined using computed tomography. Patients with SA were included and divided into two groups based on emphysema quantity (≥5% or <5%). They received either anti-IgE (22.1%), anti-IL-5-(receptor) (52.3%), or anti-IL-4/IL-13 (25.6%) biologic therapy. Treatment response was assessed after 7.8 ± 2.5 months based on acute exacerbations (AE), oral corticosteroid (OCS) therapy, Asthma Control Test (ACT), forced expiratory volume in 1 second (FEV1) and using the Biologics Asthma Response Score (BARS).

This study comprised 86 patients (mean age 56.1 ± 12.8 years; 54% female). Half (43, 50.0%) were never-smokers, half ex-smokers with an average of 26.9 ± 18.2 pack-years. Patients with ≥5% emphysema were more often ex-smokers (80% vs 41%, p=0.002), had poorer lung function (FEV1 median 1.3 [interquartile range: 1.0;1.6] vs 1.8[1-2;2.4] L, p=0.037), and more comorbid COPD (50% vs 21%, p=0.012). However, no significant differences were noted in treatment response regarding annualized AE rate (-2.5[-5;-1] vs -3.0[-5;-2] n/year, p=0.295) and OCS reduction (-4[-10;0] vs -5[-10;0] mg, p=0.691), ACT score (5[3;9] vs 4[0;9] points, p=0.579) or FEV1 improvement (0.03[-0.15;0.25] vs 0.23[-0.5;0.49] L, p=0.052), BARS (p=0.312), and remission rates (15.0% vs 19.7%, p=0.753).

In patients with severe asthma, those with comorbid emphysema show similar treatment response to biologic therapy. Therefore, suitable patients should not be denied biologics due to the presence of emphysema.