Efficacy and Safety of IL-4Rα and IL-5/IL-5R Targeted Biologic Therapies in Type 2 Inflammatory Airway Diseases: A Systematic Review and Meta-Analysis

Background/Objectives: Severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) frequently coexist and are associated with type 2 inflammation, leading to poor symptom control and high healthcare burden. Biologic therapies targeting IL-4Rα and IL-5/IL-5R have shown efficacy in type 2 inflammatory asthma and CRSwNP, but comprehensive evidence on their efficacy, safety, and research trends is limited. Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating dupilumab, mepolizumab, benralizumab, or reslizumab in patients with type 2 inflammatory asthma and/or CRSwNP. Primary outcomes included lung function (FEV1), symptom control (ACQ, SNOT-22, nasal polyp score), and serious adverse events (SAEs). Risk of bias was assessed using the Cochrane RoB 2.0 tool. Publication bias was evaluated with funnel plots and Trim-and-Fill analysis. Bibliometric analysis was performed to identify publication trends and emerging research directions. Results: A total of 23 RCTs involving 8758 participants were included. Biologic therapy was not associated with a significant increase in serious adverse events (RR = 1.15, 95% CI: 0.89–1.50). Compared with control treatment, biologics significantly improved FEV1 (MD = 100.67 mL, 95% CI: 65.94–135.40) and ACQ scores (MD = −0.40, 95% CI: −0.54 to −0.25). In patients with CRSwNP and comorbid asthma, biologics also improved SNOT-22 scores (MD = −13.16, 95% CI: −24.85 to −1.47) and nasal polyp scores (MD = −1.31, 95% CI: −1.95 to −0.68). Dupilumab trials showed larger reductions in nasal polyp score than IL-5/IL-5R-targeted trials, although this indirect comparison should be interpreted cautiously. Bibliometric analysis indicated increasing research attention to upstream epithelial targets such as TSLP. Conclusions: Both IL-4Rα and IL-5/IL-5R-targeted biologics are effective and well-tolerated in type 2 inflammatory airway diseases. IL-4Rα inhibition shows favorable upper-airway outcomes in CRSwNP with asthma, but head-to-head trials are needed to clarify its comparative efficacy relative to IL-5/IL-5R-targeted therapies. Emerging research directions are shifting toward upstream epithelial alarmin antibodies.