Benralizumab in severe eosinophilic asthma: a comprehensive systematic review and meta-analysis of randomized controlled trials evaluating lung function, asthma control, and safety outcomes

BACKGROUND: Benralizumab, a monoclonal antibody, targets eosinophils by blocking an interleukin-5 receptor, improving severe allergic asthma. Severe eosinophilic asthma affects about 10% of asthma patients and often requires high-dose corticosteroids, which are linked to adrenal insufficiency and poor outcomes. This study will perform a detailed review and meta-analysis to evaluate the effectiveness and safety of benralizumab in eosinophilic asthma. METHOD: The analysis included relevant RCTs identified through systematic searches of PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from April 2013 to January 2024. The study included variables such as exacerbation, Asthma Control Questionnaire (ACQ), forced expiratory volume (FEV₁), and adverse events. RESULTS: A total of 5502 patients with eosinophilic asthma were enrolled across 15 randomized-controlled trials; 3061 received benralizumab and 2441 received placebo. A meta-analysis showed that benralizumab significantly improved FEV₁ compared with control, with a pooled mean difference of 0.107 L (95% CI 0.059, 0.155; p < 0.001). Using a random-effects model with Hartung-Knapp adjustment, the pooled mean difference was - 0.174 (95% CI - 0.326, - 0.022; p = 0.030), indicating a statistically significant improvement in ACQ while the pooled odds ratio (OR) for adverse effects was 0.93 (95% CI 0.71, 1.23; p = 0.583) showing no statistically significant difference between benralizumab and control in the risk of adverse effects. CONCLUSION: The meta-analysis indicated that benralizumab provides significant improvement in lung function (FEV₁) and asthma control (ACQ) compared to placebo in severe eosinophilic asthma. Clinically, the average FEV₁ improvement of approximately 0.11 L represents a small but valuable gain for patients with significant baseline obstruction, though it falls below the threshold for a minimal clinically important difference (MCID) in ACQ scores. However, substantial heterogeneity was observed across studies, demonstrating that these pooled estimates represent average effects and that individual patient responses may vary considerably. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42024548225.