The U.S. Food and Drug Administration (FDA) has approved Nucala (mepolizumab) as an adjuvant maintenance medication for adults with chronic obstructive pulmonary disease (COPD) who exhibit an eosinophilic phenotype. This approval applies to patients whose condition remains inadequately controlled. This drug is manufactured by the GSK pharmaceutical industry company (plc).
Nucala is a monoclonal antibody (IgG1 kappa) that targets interleukin-5 (IL-5), which is a key cytokine involved in type 2 inflammation. It has been developed to treat various IL-5-mediated diseases linked to this type of inflammation. Nucala is currently approved for use in four IL-5-mediated conditions in Europe and five in the United States. No other country has presently approved this medication for treating COPD patients. Both Europe and China are reviewing regulatory documents.
COPD is a chronic and progressive lung disease affecting over 390 million people worldwide. It is the third leading cause of death worldwide. Despite standard therapies, many patients experience ongoing symptoms and exacerbations, which can cause irreversible lung damage. Early intervention is crucial for reducing exacerbations and preserving lung function.
Nucala is the only approved biologic shown to be effective in COPD patients with an eosinophilic phenotype defined by a blood eosinophil count (BEC) of ≥150 cells/µL. BEC was measured through a simple blood test and serves as a biomarker for the risk of exacerbation and type 2 inflammation. In the U.S., about 70% of COPD patients who remain inadequately controlled on inhaled triple therapy and continue to experience exacerbations have BECs of 150 cells/µL or higher. This accounts for more than one million people who may benefit from adding Nucala to their treatment to help reduce the risk of exacerbation and hospitalization.
This FDA approval of mepolizumab was based on results from METREX and MATINEE Phase 3, double-blind, randomized (1:1), parallel-group clinical trials. These studies evaluated the safety and efficacy of mepolizumab 100mg as an adjunct to optimal inhaled triple therapy (dual long-acting bronchodilators plus inhaled corticosteroid) when administered subcutaneously every 4 weeks versus placebo.
In both clinical studies, mepolizumab significantly reduced the annual rate of moderate or severe COPD exacerbations in patients with an eosinophilic phenotype when added to triple inhaled therapy. In MATINEE, the rate ratio (RR) was found to be 0.79 with a 95% confidence interval (CI) of 0.66-0.94 and p = 0.01. In METREX, the RR was 0.82 with a 95% CI of 0.68-0.98 and p = 0.04. In MATINEE, a secondary outcome showed a reduction in exacerbations requiring emergency or hospital care compared to the placebo (RR = 0.65, 95% CI: 0.43-0.96), although this difference was not statistically significant. The most common adverse reactions occurred in 5% or more of trial participants, including cough, back pain, and diarrhea. COPD-related hospitalizations pose a growing healthcare burden and are projected to become one of the leading causes of medical admissions. Inpatient care and emergency visits already contribute approximately $7 billion in annual direct medical costs in the U.S.
“The US FDA approval of Nucala offers a new treatment option for COPD patients with eosinophilic phenotype, including those with a BEC of 150 cells/µL or higher,” said Kaivan Khavandi, global head of respiratory, immunology & inflammation R&D, GSK. Jean Wright, CEO of the COPD Foundation, stated that there is a need for improved exacerbation management and that biologics, such as mepolizumab, are promising advancements that bring renewed hope to those living with COPD.
Reference:
- Nucala (mepolizumab) was approved by US FDA for use in adults with chronic obstructive pulmonary disease (COPD). Published May 22, 2025. Accessed May 27, 2025. Nucala (mepolizumab) approved by US FDA for use in adults with chronic obstructive pulmonary disease (COPD)
- US Prescribing Information of Nucala. Revised May 2025. US Prescribing Information of Nucala
