Table 1

Key study characteristics and methods

PopulationAll patients receiving ≥1 dose of mepolizumab or placeboPatients with blood eosinophils ≥150 cells·μL−1 at screening or ≥300 cells·μL−1Patients with blood eosinophils ≥150 cells·μL−1 at screening or ≥300 cells·μL−1
Intervention 1Mepolizumab 100 mg s.c. (n=417)Mepolizumab 100 mg s.c. (n=233)Mepolizumab 100 mg s.c. (n=223)
Intervention 2Mepolizumab 300 mg s.c. (n=225)
ControlPlacebo (0.9% saline) s.c. (n=419)Placebo (0.9% saline) s.c. (n=229)Placebo (0.9% saline) s.c. (n=226)
Key inclusion criteriaCOPD diagnosis: history of COPD for ≥1 year in accordance with the definition provided by the American Thoracic Society/European Respiratory Society [17]
FEV1 to FVC ratio <0.70 before and after bronchodilator use and a post-bronchodilator FEV1 >20% and ≤80% of the predicted value
≥2 moderate COPD exacerbations (use of systemic corticosteroids and/or treatment with antibiotics) or ≥1 severe COPD exacerbation (required hospitalisation)
Triple inhaled therapy for at least 12 months prior to screening including 3 months of an ICS at dose ≥500 μg·day−1 fluticasone propionate dose equivalent, plus LABA and LAMA; or must be taking for 12 months prior to screening (but not in 3 months immediately prior) ICS plus LABA or LAMA and a phosphodiesterase-4 inhibitor, methylxanthine, or a combination of short-acting β2-agonist and short-acting muscarinic antagonist
≥40 years of age at screening
Confirmed COPD with no restrictions on smoking status (smoker, nonsmoker, never-smoker)
Key exclusion criteriaCurrent diagnosis of asthma
Previous history of asthma in never-smokers
Other respiratory disorders, including α1-antitrypsin deficiency, active tuberculosis, lung cancer, bronchiectasis, sarcoidosis, lung fibrosis, primary pulmonary hypertension, interstitial lung diseases or other active pulmonary diseases
Pneumonia, exacerbation, lower respiratory tract infection within 4 weeks prior to screening
Other conditions causing elevated eosinophils or parasitic infection
RandomisationComputer-generated, permuted block
Primary end-pointYearly rate of moderate to severe exacerbations
Secondary end-pointsTime to first exacerbation
Emergency department visits
Average yearly change in St George's Respiratory Questionnaire score
Average yearly change in COPD Assessment Test score
Pre-specified meta-analysisBlood eosinophil stratification based on the following thresholds: <150 and a history of ≥300 cells·μL−1 in the previous year; ≥150 to <300 cells·μL−1; ≥300 to <500 cells·μL−1; and ≥500 cells·μL−1
Post hoc meta-analysisBlood eosinophils <150 cells·μL−1, blood eosinophils ≥300 cells·μL−1
Effect of mepolizumab compared to placebo on moderate/severe exacerbations treated with glucocorticoids (alone or in addition to antibiotics), or those treated with antibiotics alone

FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ICS: inhaled corticosteroid; LABA: long-acting β2-agonist; LAMA: long-acting muscarinic-receptor antagonist.