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

Background: 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.

Methods: 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).

Results: 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).

Conclusion: 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.