Clinical and Economic Burden of Severe Asthma Among US Patients Treated with Biologic Therapies

Background Severe asthma patients may remain uncontrolled despite biologic therapy in addition to standard therapy, but this disease burden has not been quantified. Objective To estimate the clinical and economic burden in a US national sample. Methods Severe asthma patients with indicated biologic treatment (earliest use=index date) were selected from the MarketScan database between 1/1/2013-6/30/2018. Inclusion criteria were continuous enrollment for 12 months post-index with minimum of 2 biologic fills, ≥12 years of age, evidence of medium-to-high dose ICS/LABA combination prior to index, and absence of other respiratory diagnoses and malignancies. Disease exacerbations (used to classify asthma control), healthcare costs, and treatment characteristics were reported during the 12-month post-index period. Results The sample included 3,262 biologic patients; 88% with anti-IgE therapy (omalizumab) and 12% non-anti-IgE (reslizumab, mepolizumab, benralizumab). The mean age was 49 (+/-15) years; 64% were female. Prescriptions included ICS/LABA (82%), systemic corticosteroids (76%), and leukotriene receptor antagonists (68%). 63% of patients presented ≥1 asthma exacerbation (mean 1.3 per patient/year). 35% of patients were categorized as having controlled asthma, 28% suboptimally controlled, and 29% uncontrolled. Patients with uncontrolled disease had higher all-cause and asthma-related costs ($69,206 and $45,693, respectively) than patients with suboptimally controlled ($59,407 and $40,793, respectively) or controlled disease ($53,083 and $38,393, respectively). 62% of newly treated patients were persistent with their index biologic. Conclusion Biologic therapies are effective in reducing exacerbations, but a significant proportion of severe asthma patients treated with current biologics continue to experience uncontrolled disease, highlighting a remaining unmet need for patients with severe uncontrolled asthma.