Targeting Blood Eosinophil Counts in COPD Treatment

Patients with chronic obstructive pulmonary disease (COPD) treated with mepolizumab may experience a lower annual number of exacerbations compared with placebo, according to a study published in the New England Journal of Medicine.

Researchers conducted 2 phase 3, randomized, placebo-controlled, double-blind, parallel-group trials (METREX and METREO; ClinicalTrial.gov identifiers: NCT02105948 and NCT02105961) comparing the effects of the monoclonal antibody drug mepolizumab with placebo on exacerbation rates in patients with COPD who were on triple maintenance therapy with glucocorticoids.

In the first study, METREX, researchers found the mean annual rate of moderate to severe COPD exacerbations in patients identified as possessing an eosinophilic phenotype was 1.40 per year in patients treated with mepolizumab, and 1.71 per year in patients in the placebo group  (rate ratio, 0.82, 95% CI, 0.68-0.98; adjusted P =.04). Patients were categorized as having either an eosinophilic phenotype (eosinophil count, ≥150 per cubic millimeter at screening or ≥300 per cubic millimeter in the previous year) or a noneosinophilic phenotype (eosinophil count, <150 per cubic millimeter at screening and no evidence of ≥300 per cubic millimeter in the previous year).

The second study, METREO, found the mean annual rate of moderate to severe COPD exacerbations to be 1.19, 1.27, and 1.49 per year in the 100 mg mepolizumab, 300 mg mepolizumab, and placebo group, respectively. The rates ratio was 0.80 for exacerbations in the mepolizumab treatment groups compared with placebo (95% CI, 0.65-0.98; adjusted P =.07). Unlike METREX, all of the METREO patients had a blood eosinophil count of ≥150 per cubic millimeter at screening or ≥300 per cubic millimeter in the previous year.

Results from both studies demonstrated a statistically significant decrease in COPD exacerbations in patients with an eosinophilic phenotype treated with mepolizumab compared with patients treated with placebo, and can be considered effective treatment in patients with elevated blood eosinophilic levels.

Disclosures: Both studies were funded by GlaxoSmithKline, the manufacturer of meopolizumab. Full disclosures are available online at NEJM.org.

Reference

Pavord ID, Chanez P, Criner GJ, et al.  Mepolizumab for eosinophilic chronic obstructive pulmonary disease [published online September 12, 2017].  N Engl J Med. doi:10.1056/NEJMoa1708208