Omalizumab in Allergic Bronchopulmonary Aspergillosis: A Systematic Review and Meta-Analysis

Background: An unmet clinical need exists in the management of treatment-refractory allergic bronchopulmonary aspergillosis (ABPA). Omalizumab has shown promising effects in case series and cohort studies; however, evidence to support its routine clinical use is lacking. Objective: The aim of this systematic review and meta-analysis was to evaluate the clinical effectiveness and safety of omalizumab in patients with ABPA. Methods: We conducted a systematic search across standard databases using specific key words until May 13, 2021. We performed a meta-analysis to compare the effectiveness (exacerbations, oral corticosteroid [OCS] use, lung function, and patient-reported asthma control) and safety of pre- and post-omalizumab treatment. Subgroup analyses were performed for treatment duration and underlying disease. Results: In total, 49 studies (n = 267) were included in the qualitative synthesis and 14 case series (n = 186) in the quantitative meta-analysis. Omalizumab treatment significantly reduced the annualized exacerbation rate compared with pretreatment (mean difference, −2.09 [95% CI, −3.07 to −1.11]; P < .01). There was a reduction in OCS use (risk difference, 0.65 [95% CI, 0.46-0.84]; P < .01), an increase in termination of OCS use (risk difference, 0.53 [95% CI, 0.24-0.82]; P < .01), and a reduction in OCS dose (milligrams per day) (mean difference, −14.62 [95% CI, −19.86 to −9.39]; P < .01) in ABPA patients receiving omalizumab. Omalizumab improved FEV₁ % predicted by 11.9% (95% CI, 8.2-15.6; P < .01) and asthma control, and was well-tolerated. Conclusions: Omalizumab treatment reduced exacerbations and OCS use, improved lung function and asthma control in patients with ABPA, and was well-tolerated. The results highlight the potential role of omalizumab in the treatment of ABPA.