Pooled data from 2,089 patients show that mepolizumab reduced mean total yearly systemic corticosteroid exposure compared with placebo in patients with chronic obstructive pulmonary disease and type 2 inflammation.
Patients enrolled in the METREX trial received mepolizumab regardless of blood eosinophil count. The METREO trial required a screening blood eosinophil count of at least 150 cells per microliter or at least 300 cells per microliter in the prior year. The MATINEE trial required a screening blood eosinophil count of at least 300 cells per microliter alongside at least 150 cells per microliter in the prior year. Systemic corticosteroid doses were converted to prednisolone equivalents and categorized into low and high thresholds.
High-Dose Courses Drive the Reduction Gap
Among 1,713 patients with a blood eosinophil count of at least 150 cells per microliter, mean total systemic corticosteroid exposure reached 434.64 mg per year with mepolizumab compared with 609.95 mg per year with placebo. That yielded a mean difference of 178.97 mg per year, with a 95% confidence interval ranging from 62.09 to 292.19 mg per year, as detailed in research published in CHEST.
For the 1,144 patients with a blood eosinophil count of at least 300 cells per microliter, mean exposure was 354.28 mg per year for the mepolizumab arm against 551.52 mg per year for the placebo arm. This produced a mean difference of 193.58 mg per year, with a 95% confidence interval of 84.01 to 306.80 mg per year. Investigators noted that the overall reduction stemmed specifically from high-dose courses, while low-dose systemic corticosteroid days remained similar across treatment arms.
Corticosteroid Use by Patient Eosinophil Thresholds
In the patient group with a blood eosinophil count of at least 150 cells per microliter, 57% received systemic corticosteroids for any cause, while 55% of patients with a count of at least 300 cells per microliter did so. The mean percentage of days without receiving systemic corticosteroids was 89.8% for mepolizumab and 88.3% for placebo in the lower threshold group. In the higher threshold group, those figures were 90.8% and 88.9%, respectively.
When looking strictly at high-dose days within the 150 cells per microliter cohort, patients on mepolizumab spent a mean of 4.5% of days on high doses compared with 5.9% for placebo. Low-dose days were identical at 5.7% for both arms. In the 300 cells per microliter cohort, high-dose days stood at 3.8% versus 5.1%, while low-dose days tracked at 5.4% and 6.1%.
CHEST 2026 Presentation Schedule
The complete findings are slated for presentation on Tuesday, October 20, from 1:45 pm to 2:30 pm MST, as part of the rapid fire original investigation session titled Precision COPD: Type 2 Inflammation, Biomarkers, and Targeted Therapy at CHEST 2026.
Blood Eosinophil Count Thresholds Across Trials
What blood eosinophil count thresholds were used across the three trials?
METREX enrolled patients regardless of blood eosinophil count, METREO required a screening count of at least 150 cells per microliter or at least 300 cells per microliter in the prior year, and MATINEE required a screening count of at least 300 cells per microliter alongside at least 150 cells per microliter in the prior year.
How many total patients were included in the pooled analysis?
The pooled analysis evaluated 2,089 patients, split between 1,043 receiving mepolizumab and 1,046 receiving placebo.
What specific trial sessions feature these findings?
The Precision COPD: Type 2 Inflammation, Biomarkers, and Targeted Therapy rapid fire original investigation session at CHEST 2026 showcases the entire set of data.
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