Dupilumab Improves Lung Function and Reduces Severe Exacerbations in Patients from China with Type 2 Asthma: A Subgroup Analysis of a Phase 3 Randomized Trial.

PURPOSE: Asthma affects approximately 46 million adults in China. The safety and efficacy of dupilumab, a monoclonal antibody which blocks the shared receptor component for interleukin (IL)-4 and IL-13, were evaluated in a phase 3 study in patients with moderate-to-severe asthma in the Asia-Pacific region (NCT03782532). This is a pre-specified subgroup analysis of patients in China derived from the Asia-Pacific trial. PATIENTS AND METHODS: Patients (≥12 years) with inadequately controlled asthma despite medium/high-dose inhaled corticosteroids and ≥1 additional controller were included. Patients with type 2 inflammation (eosinophil counts ≥150 cells/µL or fractional exhaled nitric oxide ≥25 parts per billion) without maintenance oral corticosteroids (OCS) (type 2 non-OCS group, for primary efficacy analysis) were randomized 1:1 to receive 200-mg dupilumab every 2 weeks or placebo for 24 weeks. In this pre-specified subgroup analysis, primary efficacy endpoints examined included change from baseline in pre-bronchodilator forced expiratory volume in 1 second (FEV1) to week 12. Additional outcomes assessed included asthma control measures, annualized severe exacerbation rates, and safety. RESULTS: In a total of 412 patients randomized from China (206 per treatment group) 347 (84.2%) were included in the primary efficacy analysis. Changes from baseline to week 12 in FEV1 were significantly greater for dupilumab vs placebo (least squares [LS] mean difference: 0.34 L [95% confidence interval (CI): 0.25, 0.43]), as were improvements in 5-Item Asthma Control Questionnaire scores at week 24 (LS mean difference: -0.19 [95% CI: -0.35, -0.03]). Severe exacerbation risk was significantly reduced by 74.2% (risk ratio: 0.258 [95% CI: 0.127, 0.521], P = 0.0002) vs placebo. Treatment-emergent adverse event rates were similar across groups. CONCLUSION: In this 24-week subgroup analysis, dupilumab improved lung function, asthma control, and exacerbations, and was well tolerated in patients from China with type 2 asthma without maintenance OCS.