Effectiveness of dupilumab in patients with severe asthma and coexisting COPD

Introduction Dupilumab, a monoclonal antibody targeting interleukin-4 receptor alpha (IL4-Rα), reduces exacerbations in patients with either severe asthma (SA) or chronic obstructive pulmonary disease (COPD). However, SA and COPD frequently coexist, and real-world evidence on dupilumab effectiveness in this overlapping population is limited. Aim To compare treatment responses to dupilumab in patients with SA and coexisting COPD (SA+COPD) versus patients with SA only. Methods This nationwide observational study used data from the Danish Severe Asthma Register and included all dupilumab-treated SA patients with complete one-year follow-up. COPD was defined as forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) <0.70, tobacco exposure ≥10 pack-years, and age >40 years. Changes in exacerbations, maintenance oral corticosteroid (mOCS) dose, symptom control (ACQ-6), and complete response (no exacerbations and no mOCS use) were assessed after 12 months. Results Among 401 patients, 93 (23%) had SA+COPD. After 12 months of dupilumab, the percentage reduction in mean exacerbations was 61% in the SA+COPD group and 81% in the SA-only group (p=0.06). Reductions in mean daily mOCS dose were 3.1 mg [ sd 3.0] in SA+COPD and 4.3 mg [ sd 8.75] in SA only (p=0.46). ACQ-6 scores improved similarly in both groups, with mean reductions of −0.86 [ sd 1.25] and −0.86 [ sd 1.26], respectively (p=0.85). However, complete response was less frequent in SA+COPD compared with SA only (51% versus 70%, p=0.001). Conclusion Coexisting COPD was common among patients with SA and did not significantly reduce dupilumab effectiveness, although it may reduce the likelihood of achieving a complete response.