mepolizumab for maintenance treatment of uncontrolled chronic obstructive pulmonary disease with raised blood eosinophils

Mepolizumab is a monoclonal antibody that targets interleukin-5 (IL-5), a cytokine responsible for the recruitment, activation, and survival of eosinophils (1,2):

• early COPD arly studies using induced sputum to assess airway inflammation identified eosinophilic airway inflammation as reflected by a raised induced sputum eosinophil count in up to 30% of patients
• blood eosinophil count is a biomarker indicating type 2 inflammation in patients with chronic obstructive pulmonary disease (COPD) (2)
• type 2 inflammation is associated with the risk of exacerbations and a positive response to oral and inhaled corticosteroids
• clinically, type-2 inflammation is reflected by measurable biomarkers such as blood eosinophil count and exhaled nitric oxide (FeNO), which are linked to ongoing airway inflammation
• has already been approved for the treatment of severe eosinophilic asthma and eosinophilic granulomatosis with polyangiitis (EGPA)
• has been shown thet mepolizumab improved exacerbation-related outcomes in patients with COPD and type 2 inflammation, characterized by both consistently and intermittently elevated blood eosinophil counts (2)

A review suggests key benefits of Mepolizumab include (1):

• reduction in exacerbation rates, especially in patients with higher blood eosinophil counts
• potential to reduce the need for systemic corticosteroids, which are associated with significant side effects in COPD patients
• improved quality of life for patients with frequent exacerbations by reducing the physical and emotional burden of these events

NICE state (3):

Mepolizumab can be used as an add-on maintenance treatment option for uncontrolled* chronic obstructive pulmonary disease (COPD) with raised blood eosinophils in adults, if:

• they are having triple therapy including an inhaled corticosteroid (ICS), a long-acting beta-2-agonist (LABA) and a long-acting muscarinic antagonist (LAMA), and
• the company provides mepolizumab according to the commercial arrangement

*Uncontrolled COPD is defined as 1 or more severe exacerbations or 2 or more moderate exacerbations in the previous 12 months. Raised blood eosinophils is defined as a blood eosinophil count of 0.3 x 10⁹ cells per litre or more (300 cells per microlitre or more).

NICE suggest that there should be an assessment of the response to mepolizumab at 12 months. Stop mepolizumab if, compared with the 12 months before starting it, the number of severe exacerbations:

• is higher, or
• is the same, and the number of moderate exacerbations is higher.

Reference:

1. Rabahi M, Pavord ID. Drug evaluation: mepolizumab in chronic obstructive pulmonary disease. Immunotherapy. 2025 Apr;17(6):399-408.
2. Criner CJ et al. Mepolizumab Efficacy in COPD: Insights from Longitudinal Patterns of Blood Eosinophil Counts and Their Variability Across Three Clinical Trials. Am J Respir Crit Care Med. 2026 Jun 9:aamag288.
3. NICE (June 2026). Mepolizumab for maintenance treatment of uncontrolled chronic obstructive pulmonary disease with raised blood eosinophils.