Switching Biologics in Severe Asthma Patients Shows Improved Clinical Outcomes and Reduced Exacerbations Across Multiple Therapies

BACKGROUND: This systematic review (SR) aims to delineate the patterns and rationales for biologic switching in patients with severe asthma and evaluate its efficacy across the clinical remission criteria. METHODS: The SR followed the PRISMA guidelines (PROSPERO CRD420251155819), with searches up to September 2025. Studies reporting on switching of biologics, including anti-IgE, anti-IL-4R/13R, anti-IL5/5R, and anti-TSLP, were included. Standardized mean difference (SMD) or mean difference (MD), and pooled relative risk (RR) were calculated for pre- and post- switch comparisons. RESULTS: The SR included 49 studies (2292 switched severe asthma patients). The most common switching patterns were mepolizumab-benralizumab (n = 637) and omalizumab-mepolizumab/benralizumab (n = 386 or 305, respectively). Additional switching patterns included transitions from other biologicals to dupilumab or tezepelumab. Suboptimal asthma control (n = 1005, 77.0%) was the predominant reason for switching. The switch led to a significant reduction in exacerbations (SMD -1.03, 95% CI: -1.26 to -0.80, I = 89%), emergency department visits, hospitalizations, and maintenance oral corticosteroid dose and to improved asthma control ACT MD 5.18 (95% CI 4.32 to 6.04, I = 80%), ACQ MD -1.05 (95% CI -1.26 to -0.83, I = 45%) and lung function FEV1 MD 0.18 L (95% CI: 0.11 to 0.25, I = 0%). T2-biomarkers (blood eosinophils, total serum IgE, FeNO) significantly decreased. CONCLUSION: Biologics switching represents a promising strategy supported by high-quality evidence of its clinical efficacy. Switching should consider clinical remission goals, co-morbidities, side effects, costs and reimbursement policies, and patient preferences.