Mepolizumab Reduces Asthma Exacerbations, Costs in Those Covered by Medicare

Mepolizumab treatment of Medicare patients with severe eosinophilic asthma reduced exacerbation frequency, oral corticosteroid (OCS) use, and asthma exacerbation-related health care costs, according to an analysis of Medicare claims data published in The Journal of Allergy and Clinical Immunology: In Practice.

Investigators assessed the effects of initiating treatment with mepolizumab — an anti-interleukin-5 monoclonal antibody — among US Medicare patients with asthma. The primary endpoint was the change in the proportion of patients experiencing asthma exacerbations. Secondary endpoints included changes in OCS use and asthma exacerbation-related costs.

The researchers conducted a retrospective cohort study of the CMS Medicare database that included 1278 patients (mean [SD] age, 67.9 [10.6] years; 64.3% women) with a mepolizumab index date (ie, date of first claim for mepolizumab) between January 2017 and December 2017. The “baseline period” was defined as the 12 months pre-index date and the “follow-up period” was defined as the 12 months post-index date. Exclusion criteria included patients with at least 1 prescription for mepolizumab during the baseline period, or at least 1 prescription for omalizumab, reslizumab, benralizumab, or dupilumab during the baseline or follow-up period. Most common comorbidities included hypertension (75%), chronic obstructive pulmonary disease (69%), allergic rhinitis (62%), and gastroesophageal reflux disease (56%).

Investigators found a significant relative reduction (27%; P <.0001) in the proportion of patients with an asthma exacerbation during the follow-up vs baseline period. Asthma exacerbations were defined as an outpatient or emergency room claim with an asthma diagnosis and at least 1 claim for systemic corticosteroids within 5 days of that visit, or a hospital admission with primary diagnosis of asthma.

A significantly lower proportion of patients received OCS (16% relative reduction; P <.0001) during the follow-up vs baseline period. Fewer patients were chronic OCS users (≥5mg/day) during the follow-up vs baseline period (48% relative reduction; P <.0001). A significant decrease in asthma-exacerbation-related costs (total reduction $888.00; P =.0002) was observed during follow-up vs baseline.

Study limitations include lack of accounting for disease progression, changes in patient characteristics, or changes in treatment; the lack of clinical evaluation data of patients analyzed; lack of confirmation that those prescribed mepolizumab actually used it; and non-inclusion of the cost of mepolizumab in pharmacy cost data.

Investigators concluded that among US Medicare patients with asthma in a real-world setting, “treatment with mepolizumab was likely to result in fewer exacerbations, reductions in OCS use, and cause a reduction in exacerbation-related healthcare costs.” They added that “Our study suggests that in carefully selected elderly patients with severe asthma, anti-IL5 biologic therapy with drugs such as mepolizumab could be of benefit and should be considered.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This research was supported by GlaxoSmithKline.