Mepolizumab Reduces COPD Exacerbation Rate, Burden in Pooled Phase 3 Data

Published on: October 22, 2025

Conference | American College of Chest Physicians

Emmeline Burrows, PharmD, discusses the significance of new CHEST 2025 data showing the benefit of mepolizumab across a diverse population of patients with COPD.

Mepolizumab (NUCALA) provided an 18% reduced risk of annual moderate to severe exacerbations versus placebo in patients with chronic obstructive pulmonary disease (COPD), according to data from a pooled phase 3 trial analysis presented at the American College of Chest Physicians (CHEST) 2025 Annual Meeting in Chicago, IL, this week.

The new findings, presented during CHEST 2025 late-breaking sessions, additionally showed the interleukin-5 (IL-5)-targeting biologic therapy reduced hazard of reaching a first exacerbation at any point over 2 years by 20% versus placebo (hazard ratio [HR], 0.80; 95% CI, 0.70 – 0.90; P <.001). The phase 3 data analysis was furthered bolstered by the robust and diverse patient population assessed for these outcomes: more than 1000 patients with COPD, regardless of chronic bronchitis or emphysema status and with baseline eosinophil levels of ≥150 cells/mcL, were treated with mepolizumab.

What was the clinical diversity of COPD patients including in the phase 3 analysis?

"We enrolled real-life patients — patients who have different GOLD stages, patients who had chronic bronchitis, patients who had emphysema, and those who may have a mixture of emphysema and chronic bronchitis. It's really representing those real-life patients in terms of symptoms. We also have patients with significant symptoms and those who have lower symptoms, as determined by the mMRC score. The St. George's Respiratory Questionnaire (SGRQ) score was also higher in our patient population, really showing that in those patients, regardless of symptoms, can benefit from staying out of the hospital due to the exacerbations of COPD."

In an interview with HCPLive during CHEST 2025, Emmeline Burrows, PharmD, study author and Medical Affairs Leader for GlaxoSmithKline, discussed the pooled analysis of METREX, METREO, and MATINESS — each of which assessed 100 mg subcutaneous mepolizumab versus placebo for 52 – 104 weeks among patients aged ≥40 years old with COPD and Chronic Obstructive Lung Disease (GOLD) grades from 2 – 4.

Among the most outstanding takeaways from these latest findings, Burrows explained, is that it shows even the most severely impacted COPD patients can achieve some benefit from mepolizumab.

“[These data] really indicated that mepolizumab has the ability to show significant benefit in patients with COPD and eosinophilic phenotype starting from 150 mcL and up,” Burrows said. “The mepolizumab [FDA] approval allows patients who are exacerbating on triple therapy with high blood eosinophil counts to receive benefit that could potentially perfect the way we treat COPD by preventing exacerbations, hospitalizations, and emergency department visits. The opportunity we have is here.”

Following these pooled data and the US Food and Drug Administration’s approval of mepolizumab for eosinophilic COPD this May, Burrows and colleagues are looking to publish real-world evidence supporting these effects. Her hope is further data shifts the prescribing clinician’s mindset — and goal threshold — for their patients with historically poorly controlled COPD.

“Moving from that symptomatic treatment to preventing exacerbation and progression of the disease is the pivotal change that we're expecting to see in COPD management,” Burrows said.

Burrows is an employee of GlaxoSmithKline.

References

Anzueto A, Burrows E, Biswas A, Kraft M, et al. Mepolizumab Significantly Reduces and Delays COPD Exacerbations in a Wide Spectrum of Patients: Pooled Phase III Trial Results. Poster presented at: CHEST Annual Meeting 2025. Chicago, IL. October 19 – 22, 2025.
Johnson V. FDA Approves Mepolizumab for Eosinophilic COPD. HCPLive. Published online May 22, 2025. https://www.hcplive.com/view/fda-approves-mepolizumab-for-eosinophilic-copd