Real-World Reductions in Oral Corticosteroid Use in the USA Following Mepolizumab Therapy for Severe Asthma

Background: Patients with severe asthma often require oral corticosteroid (OCS) treatment. Clinical trials have demonstrated that mepolizumab can reduce OCS dependence, but real-world data are limited.

Objective: To evaluate the impact of mepolizumab on OCS use, asthma exacerbations, and asthma exacerbation-related costs in a real-world setting.

Methods: This retrospective cohort study (GSK ID: 209642; HO-19-19597) analyzed data from the MarketScan^® Commercial database (identification period: November 2015-September 2017). Patients were ≥12 years old at mepolizumab initiation (index date), had a baseline asthma diagnosis, and received ≥2 mepolizumab administrations in the first 6 months of follow-up. OCS use, asthma exacerbation rate, and asthma exacerbation-related costs were assessed in the 12-months before (baseline) and 12-months after (follow-up) mepolizumab initiation.

Results: Mepolizumab was associated with a 14.7% reduction in the proportion of patients with ≥1 OCS claim from baseline to follow-up (93.4% vs 79.7%; P<0.001). The mean numbers of OCS claims/patient and OCS bursts (≥20 mg prednisone equivalents for 3‒28 days) between baseline and follow-up were also reduced by 29.1% (P<0.001) and 36.8% (P<0.001), respectively. Reductions in chronic OCS use were demonstrated during follow-up in patients with baseline mean OCS dose ≥5mg and those with a mean OCS dose ≥10mg 90 days before index; the proportion of patients with no OCS use also increased from 6.6% to 20.3% between baseline and follow-up.

Conclusion: Our findings demonstrate that mepolizumab therapy is associated with reduced OCS use in patients treated in a real-world setting, potentially mitigating adverse health sequelae caused by OCS use in these patients.