Mepolizumab modestly cut COPD flare-ups, with no gain in quality of life
In the GSK-funded phase 3 MATINEE trial, the anti-IL-5 antibody lowered moderate or severe exacerbations from 1.01 to 0.80 a year — but symptom and quality-of-life endpoints showed no significant benefit.
| Group | Value (value) |
|---|---|
| Mepolizumab | 0.8 |
| Placebo | 1.01 |
Mepolizumab, a monoclonal antibody already used in severe asthma, reduced flare-ups of chronic obstructive pulmonary disease in patients whose disease is driven by eosinophilic inflammation, according to the phase 3 MATINEE trial published in The New England Journal of Medicine [s1]. The benefit was statistically clear but modest in size, and the trial's own hierarchy of secondary endpoints stopped early when the drug failed to improve symptoms or quality of life — a result that sets a realistic ceiling on what this biologic offers.
COPD is a progressive lung disease treated mainly with inhaled bronchodilators and steroids, but a subset of patients keep having exacerbations despite optimised inhalers. Mepolizumab targets interleukin-5, a cytokine central to the eosinophilic inflammation that is present in 20 to 40% of people with COPD, and MATINEE tested whether blocking that pathway helps the patients most likely to have it [s1].
What the trial did
MATINEE was a double-blind, randomised, placebo-controlled trial [s1]. It enrolled patients with COPD, a history of exacerbations and a blood eosinophil count of at least 300 cells per microlitre who were already receiving triple inhaled therapy — the maximal standard inhaler regimen [s1]. Participants were assigned in a 1:1 ratio to receive mepolizumab at a dose of 100 mg or placebo subcutaneously every 4 weeks for 52 to 104 weeks [s1]. Of the 804 patients who underwent randomisation, 403 were assigned to mepolizumab and 401 to placebo [s1]. The primary endpoint was the annualised rate of moderate or severe exacerbations [s1].
The result
Mepolizumab met its primary endpoint. The annualised rate of moderate or severe exacerbations was 0.80 events per year with the drug versus 1.01 with placebo — a rate ratio of 0.79 (95% confidence interval, 0.66 to 0.94; P=0.01) [s1]. Patients also went longer before their first exacerbation: the Kaplan–Meier median time to a first moderate or severe exacerbation was 419 days with mepolizumab against 321 days with placebo, a hazard ratio of 0.77 (95% CI, 0.64 to 0.93; P=0.009) [s1].
Then the results stopped improving. The secondary endpoints were tested in a fixed hierarchy to control for multiple comparisons, and the between-group differences in measures of health-related quality of life and symptoms were not significant [s1]. Because that step in the sequence failed, no statistical conclusions could be drawn about the endpoints further down the list — including the rate of exacerbations severe enough to send a patient to an emergency department or hospital [s1]. The incidence of adverse events was similar in the two groups [s1].
How it compares
A second question is whether mepolizumab is any better than the other type-2-inflammation biologic approved for the same COPD patients, dupilumab. A matching-adjusted indirect comparison published in Chest tried to answer it by reweighting patient data from three mepolizumab trials (METREX, METREO and MATINEE) to match the populations of two dupilumab trials (BOREAS and NOTUS) [s2]. It found no statistically significant difference between the two drugs in reducing the annualised rate of moderate to severe exacerbations — a rate ratio of 0.91 (95% CI, 0.60 to 1.37) under one definition of chronic bronchitis and 1.13 (95% CI, 0.80 to 1.58) under another — and no significant difference in quality-of-life scores [s2]. An indirect comparison is weaker evidence than a head-to-head trial, and its wide confidence intervals reflect that, but it gives no reason to prefer one biologic over the other on effectiveness [s2].
Who funded it
MATINEE was funded by GSK, which markets mepolizumab [s1]. The trial design — randomised, placebo-controlled, with a pre-specified endpoint hierarchy that the sponsor allowed to halt the claims when symptoms did not improve — is a strong one, and the honest reporting of the failed secondary endpoints is to its credit [s1]. Still, a sponsor's framing of the drug will lean on the significant primary result; the fuller picture includes the endpoints that did not move.
What it means
For patients with eosinophilic COPD who keep exacerbating on triple inhalers, mepolizumab adds a real but incremental option: roughly a fifth fewer moderate or severe flare-ups, and a longer gap before the first one, with no demonstrated improvement in how patients feel day to day [s1]. It is not better than the existing biologic alternative on the available evidence [s2]. Whether it is worth adding will depend on how clinicians and payers value fewer exacerbations against cost and the lack of a symptom benefit. Readers should treat mepolizumab as a targeted add-on for a specific inflammatory phenotype, not a broad advance for COPD generally.
Sources
- [s1] Mepolizumab to Prevent Exacerbations of COPD with an Eosinophilic Phenotype. The New England Journal of Medicine, 2025. https://doi.org/10.1056/NEJMoa2413181
- [s2] Mepolizumab and Dupilumab Show No Significant Difference in Reducing Exacerbations in Patients With COPD and an Eosinophilic Phenotype: Matching-Adjusted Indirect Treatment Comparison. Chest,
Sources
- Mepolizumab to Prevent Exacerbations of COPD with an Eosinophilic Phenotype — The New England Journal of Medicine , April 30, 2025
- Mepolizumab and Dupilumab Show No Significant Difference in Reducing Exacerbations in Patients With COPD and an Eosinophilic Phenotype: Matching-Adjusted Indirect Treatment Comparison — Chest , August 20, 2026
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