Dupilumab Efficacy in Patients with Chronic Obstructive Pulmonary Disease (COPD) with Type 2 Inflammation across Baseline Eosinophil Counts

Rationale: Type 2 (T2) inflammation in patients with chronic obstructive pulmonary disease (COPD) is evidenced by elevated blood eosinophil counts (BEC), often correlating with higher risk for exacerbations. This post-hoc analysis of pooled data from BOREAS and NOTUS evaluated efficacy of dupilumab in patients stratified by baseline BEC. Methods: BOREAS (NCT03930732) and NOTUS (NCT04456673), both phase 3, randomized, placebo-controlled trials, enrolled 1,874 patients (40–85 years) with COPD, moderate-to-severe airflow limitation, T2 inflammation and screening BEC≥300 cells/µL. Patients were randomized to dupilumab 300 mg or placebo q2w for 52 weeks. This analysis included patients from the intention-to-treat (ITT) population, stratified by baseline BEC (≥150 or 150–300 or≥300 cells/µL at randomization). Endpoints included annualized moderate-to-severe exacerbation rate, change from baseline to Week 52 in pre- and post-bronchodilator (BD) forced expiratory volume in 1 second (FEV 1 ) and St. George’s Respiratory Questionnaire (SGRQ) total score. Results: Of 1,873 patients, 1,703 (dupilumab n=855; placebo n=848) had baseline BEC≥150 cells/µL, and 1,135 (dupilumab n=573; placebo n=562) still had baseline BEC≥300 cells/µL. Dupilumab vs placebo reduced annualized exacerbation rates by up to 36.9%. At Week 52, dupilumab vs placebo improved pre-BD FEV 1 by least squares (LS) mean difference (95% confidence interval [CI]) 0.07 (0.04, 0.11) L in the ITT population, 0.08 (0.04, 0.11) L in patients with baseline BEC≥150 cells/µL, and 0.09 (0.05, 0.13) L in those with baseline BEC≥300 cells/µL. Similar results were observed for changes in post-BD FEV 1 . Dupilumab also reduced SGRQ total scores at Week 52 by (LS mean [95% CI])−3.37 (−4.95,−1.78) in the ITT population,−3.07 (−4.7,−1.44) at baseline BEC≥150 cells/µL and−3.98 (−6.01,−1.95) at baseline BEC≥300 cells/µL. Overall study safety of BOREAS and NOTUS was consistent with known dupilumab profile. Conclusions: In patients with COPD and T2 inflammation, dupilumab reduced annualized exacerbation rates, and improved lung function and quality of life in patients in ITT and across baseline BEC of≥150 and≥300 cells/µL, with slightly greater treatment effects observed in patient with higher baseline BEC. Publication History Article published online: 04 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany