GlaxoSmithKline (GSK) has secured a critical regulatory victory as the U.S. Food and Drug Administration (FDA) approved its biologic drug Nucala (mepolizumab) as an add-on maintenance therapy for adults with inadequately controlled chronic obstructive pulmonary disease (COPD) exhibiting an eosinophilic phenotype. This makes Nucala the second biologic therapy to receive FDA approval for COPD and the third new treatment in this therapeutic area to be greenlit in the past year.
According to GSK, the approval follows an unexpected delay earlier in the month but now enables the company to move forward with launch plans. As GSK stated,The FDA on Thursday approved Nucala as an add-on maintenance treatment for adults with inadequately controlled COPD and an eosinophilic phenotype.
The FDA’s approval is based on positive data from the MATINEE and METREX Phase III trials. In these trials, mepolizumab demonstrated a clinically and statistically significant reduction in the annual rate of moderate to severe exacerbations in patients with chronic obstructive pulmonary disease (COPD) with various eosinophilic phenotypes, compared to placebo. The primary endpoint of the studies was the annual exacerbation rate of moderate to severe COPD. Exacerbations are destructive for patients and are known to cause irreversible lung damage, worsening of symptoms, and increased mortality. The incidence of adverse events was similar between the placebo and mepolizumab groups.
Results showed that after 104 weeks of treatment, the annual exacerbation rate in the mepolizumab group was significantly lower than in the placebo group (0.80 vs 1.01, P=0.01).
Mepolizumab is a humanized anti-IL-5 monoclonal antibody that inhibits IL-5–mediated inflammatory responses by blocking the interaction between IL-5 and its receptor on eosinophils. The drug was first approved by the FDA in November 2015. Its previously approved indications globally include: add-on maintenance treatment for patients aged 6 years and older with severe eosinophilic asthma; add-on maintenance treatment for adult patients with chronic rhinosinusitis with nasal polyps (CRSwNP) who have an inadequate response to nasal corticosteroids; treatment of adults with eosinophilic granulomatosis with polyangiitis (EGPA); and treatment of patients aged 12 years and older with hypereosinophilic syndrome (HES).
In China, mepolizumab was approved by the NMPA in 2021 and is currently indicated for eosinophilic granulomatosis with polyangiitis, severe eosinophilic asthma, and chronic rhinosinusitis with nasal polyps. It has become an important targeted therapy option for diseases associated with type 2 inflammation.
With the new approval, Nucala will enter a competitive COPD market, facing off against Sanofi and Regeneron's Dupixent, which was approved for the same patient segment last September. Verona Pharma’s Ohtuvayre, which was approved in June 2023, targets a different COPD subgroup. Although Nucala and Dupixent both address patients with high eosinophil counts, GSK emphasizes Nucala’s potential differentiation through its broad trial base and impact on hospitalization rates.
Luke Miels, Chief Commercial Officer at GSK, highlighted the scope of the patient population included in the pivotal phase 3 Matinee study. He explained,We had the widest population, which is important because for a physician to stratify these patients, it’s much simpler to be able to say, ‘OK, I can use Nucala in patients whether they’ve got emphysema, chronic bronchitis or both.’
In the Matinee trial, Nucala achieved its primary endpoint by reducing the annualized rate of moderate or severe exacerbations by 21% compared to placebo. Among patients with chronic bronchitis alone, that figure rose to 31%. Additionally, GSK reported a 35% reduction in hospitalizations and emergency room visits due to exacerbations.
There’s a very high burden when you have severe exacerbations and end up being hospitalized. So, the aim is to keep patients out of the hospital, keep them stable and keep them at home,said Miels during a media briefing.
Safety outcomes were consistent with expectations, with adverse events mirroring those of the placebo group. The most common issues were related to worsening COPD symptoms.
GSK views Nucala’s entry into the COPD space as a significant business opportunity, projecting peak sales of ￡500 million (approximately $669 million) for the indication. The company confirmed it would retain Nucala’s current pricing model, which is approximately $3,800 per injection before discounts in the U.S.
The approval also extends Nucala’s FDA indication count to five, adding to its prior approvals for severe asthma, chronic rhinosinusitis with nasal polyps, eosinophilic granulomatosis with polyangiitis, and hypereosinophilic syndrome. GSK’s broader respiratory portfolio is already led by Trelegy Ellipta, the top-selling COPD inhaler.
According to GSK’s earnings data,Nucala sales across its prior four indications grew by 13% at constant currencies to 3.3 billion pounds ($4.4 billion) in 2024. The drug generated 444 million pounds ($594 million) in 2025’s first quarter, a 21% increase year-over-year.
