Impact of Demographics on Mepolizumab Effectiveness in Severe Asthma: One-Year REALITI-A Subanalysis

Background: There is need for better understanding of the impact of demographic and clinical characteristics on outcomes with mepolizumab in patients with severe asthma. Objective: To assess mepolizumab outcomes in severe asthma by demographic and clinical characteristics. Methods: REALITI-A (GSK ID: 204710) was an international, prospective, observational study of adults with severe asthma (eosinophilic phenotype) initiating mepolizumab (100 mg subcutaneously). This 1-year post hoc subanalysis assessed outcomes stratified by sex, age at asthma onset, body mass index, smoking status, disease duration, and FeNO in parts per billion. Outcomes included clinically significant asthma exacerbations (CSEs), maintenance oral corticosteroids use, Asthma Control Questionnaire-5 scores, and pre-bronchodilator FEV1 between pretreatment or baseline and 12-month follow-up. Results: Among 822 enrolled patients, 63% were female; of those with available data, 79% were aged 18 years or older at asthma onset, 60% had never smoked, and 37% were former smokers. Across all subgroups after mepolizumab treatment, CSEs were significantly reduced by 53% to 79%. Except for the current smoker subgroup, maintenance oral corticosteroid doses were numerically reduced by 50% to 100% and least-squares mean Asthma Control Questionnaire-5 scores were significantly improved by –1.02 to −1.57; least-squares mean pre-bronchodilator FEV1 significantly improved by 3.1% to 8.4% (except for the current smoker, BMI ≥30, and FeNO <25 and 25 to <50 subgroups). There were trends toward a greater reduction in CSE rates with older age at onset, body mass index less than 25 kg/m2, and nonsmoker or former smoker subgroups. Conclusion: Mepolizumab improved outcomes in patients with severe asthma over a varied demographic spectrum in this large real-world study.