Real-world effectiveness of mepolizumab in asthma: a systematic review and meta-analysis

Objective: Exacerbations and suboptimal disease control are common in severe asthma with an eosinophilic phenotype (SAep). Mepolizumab, an anti-interleukin-5 monoclonal antibody, has demonstrated efficacy and safety in randomized controlled trials (RCTs). We aimed to strengthen the real-world evidence base for mepolizumab in SAep. Methods: We analyzed data from Italian participants of REALITI-A, a global, real-world, prospective, observational study (primary outcome: rate of clinically significant exacerbations [CSEs]). Using these data and those from Italian real-world studies of mepolizumab (identified by systematic literature review), we performed a meta-analysis. Results: In the Italian cohort of REALITI-A (n = 244), mean CSE rate was lower 12 months post-mepolizumab initiation versus 12 months pre-mepolizumab (0.67 vs. 3.74 CSEs/patient/year; relative risk [RR], 0.18; 95% confidence interval (CI), 0.15–0.22; p <.001). The meta-analysis included 863 patients. Mean CSE rate decreased from 4.2/patient/year at baseline to 0.71/patient/year post-mepolizumab initiation. Mean oral corticosteroid (OCS) dose reduced by 8.66 mg/day (95% CI, 6.17–11.16 mg/day; p <.0001) from baseline (10.0 mg/day). The RR for OCS maintenance, post- versus pre-mepolizumab, was 0.37 (95% CI, 0.27–0.52; p <.0001). A mean increase in Asthma Control Test score of 6.50 (95% CI, 5.67–7.33; p <.00001) was observed. Proportions of patients reporting adverse events were low. Conclusions: Real-world experience in this unified health care system identifies that mepolizumab has a low adverse event rate and provides consistent clinical benefits. Mepolizumab represents an important treatment option for patients with SAep.