T2AIR: Real-World Efficacy and Safety of Biologics Targeting Type 2 Inflammation in Asthma and COPD

Chronic airway diseases, encompassing asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous disorders characterized by chronic airway inflammation, persistent airflow limitation, and/or airway hyperresponsiveness. These conditions commonly present with chronic cough, sputum production, and dyspnea. Acute exacerbations can be life-threatening and represent a leading global cause of disability and premature mortality among chronic non-communicable diseases. Although inhaled corticosteroids (ICS) combined with long-acting bronchodilators (LABA/LAMA) form the mainstay of treatment, a substantial proportion of patients - approximately 5-10% with asthma and selected COPD patients experience severe or refractory disease. These patients suffer from recurrent exacerbations, progressive lung function decline, impaired quality of life, and serious complications associated with long-term oral corticosteroid (OCS) use, including osteoporosis and increased infection risk. Type 2 (T2-high) inflammation, driven by eosinophil activation and the IL-4/IL-5/IL-13 signaling pathways, plays a central role in the pathogenesis of most severe asthma cases and a significant subset of COPD patients. In recent years, biologics targeting key mediators of Type 2 inflammation - including IgE, IL-5/IL-5Rα, IL-4Rα, and thymic stromal lymphopoietin (TSLP) - have emerged as precision therapeutic options for patients inadequately controlled on standard therapy. The six biologics evaluated in this study are: 1. Omalizumab (anti-IgE monoclonal antibody) 2. Mepolizumab (anti-IL-5 monoclonal antibody) 3. Benralizumab (anti-IL-5Rα monoclonal antibody) 4. Dupilumab (anti-IL-4Rα monoclonal antibody, blocking IL-4/IL-13 signaling) 5. Tezepelumab (anti-TSLP monoclonal antibody, effective in both T2-high and T2-low phenotypes) 6. Depemokimab (ultra-long-acting anti-IL-5 Fc-fusion protein enabling twice-yearly dosing) Current international guidelines (GINA 2026 and GOLD 2026) recommend these Type 2-targeted biologics as add-on therapy for moderate-to-severe patients with poor control despite optimized standard care, with selection often guided by biomarkers such as blood eosinophils (EOS) and fractional exhaled nitric oxide (FeNO). While these agents have demonstrated efficacy in randomized controlled trials (RCTs) for severe asthma and eosinophilic COPD, robust real-world evidence remains limited, long-term use, diverse phenotypes, elderly patients, and those with multiple comorbidities. Moreover, data specific to Chinese populations are scarce. This prospective real-world observational study aims to address these evidence gaps.