FDA Approves GSK’s Nucala for COPD Patients with Eosinophilic Inflammation

The U.S. Food and Drug Administration (FDA) has approved GSK’s biologic therapy, Nucala (mepolizumab), as an add-on maintenance treatment for adults with chronic obstructive pulmonary disease (COPD) who continue to experience symptoms despite standard inhaled triple therapy. The approval specifically targets patients with an eosinophilic phenotype — a subset identified by elevated levels of eosinophils in the blood.

This milestone makes Nucala the first and only biologic authorized for use in a broad population of COPD patients with this inflammatory profile, defined by a blood eosinophil count (BEC) starting at 150 cells/µL.

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Backed by Robust Clinical Data

The FDA’s decision is based on compelling results from two large Phase III trials, MATINEE and METREX. These studies demonstrated that mepolizumab, when added to standard triple inhaled therapy, significantly reduced the rate of moderate and severe COPD exacerbations compared to placebo.

In the MATINEE trial, participants receiving mepolizumab saw a meaningful reduction in flare-ups that required emergency department visits or hospitalisation. Although this secondary outcome did not reach statistical significance under the trial's strict testing hierarchy, the data still highlight mepolizumab’s potential to reduce serious health events in high-risk patients.

Notably, the safety profile of mepolizumab was comparable to placebo across both trials.

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Targeting a High-Risk Population

Around 70% of U.S. patients who remain inadequately controlled on inhaled triple therapy have BECs of 150 cells/µL or higher. This equates to over a million individuals who remain vulnerable to exacerbations — costly, debilitating episodes that can worsen lung function and increase the risk of death. Mepolizumab offers a new therapeutic option for this under-treated group.

Study Details: MATINEE and METREX

Both trials were randomized, double-blind, placebo-controlled studies evaluating 100 mg of mepolizumab given via subcutaneous injection every four weeks. Participants in MATINEE were monitored over 52 to 104 weeks and included 804 patients with a range of COPD severities — from moderate to very severe — and various disease profiles, including chronic bronchitis and emphysema. All participants had experienced at least one exacerbation in the prior year despite optimal treatment.

The METREX trial enrolled 836 patients, dividing them into two subgroups based on eosinophil counts: one with elevated levels and another without. Only those with the eosinophilic phenotype showed meaningful benefit from mepolizumab, reinforcing the importance of targeted treatment based on biomarker profiles.

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A Step Forward in COPD Management

COPD, which affects over 390 million people worldwide, remains one of the leading causes of death. Characterised by chronic inflammation, airflow obstruction, and persistent respiratory symptoms, the disease has a major impact on quality of life and healthcare systems. In the U.S. alone, emergency visits and hospital stays related to COPD cost an estimated $7 billion annually.

Mepolizumab is currently not approved for COPD in any other countries, though regulatory reviews are underway in Europe and China.

With this approval, GSK's Nucala may offer renewed hope for a significant portion of COPD patients who remain vulnerable to exacerbations despite existing therapies — providing a tailored treatment approach grounded in a patient's biological profile.