Nucala (mepolizumab) for COPD

Last updated May 29, 2025, by Marisa Wexler, MS
Fact-checked by Marta Figueiredo, PhD

What is Nucala for COPD?

Nucala (mepolizumab) is an injectable therapy approved in the U.S. for adults with poorly controlled chronic obstructive pulmonary disease (COPD) who have high counts of eosinophils, a type of immune cell.

The antibody-based therapy is used as an add-on maintenance treatment to reduce the risk of COPD exacerbations, or periods of sudden COPD symptom worsening.

Up to 40% of people with COPD have elevated eosinophils, which are involved in a form of inflammation, called type 2 inflammation, that is thought to contribute to COPD-related lung inflammation and exacerbations. Patients with high eosinophils in the blood and/or lungs have more severe disease and are at a higher risk of severe exacerbations.

Administered via under-the-skin, or subcutaneous, injections, GSK’s Nucala works by blocking the activity of interleukin-5 (IL-5), a signaling molecule that promotes the growth, maturation, and survival of eosinophils.

Therapy snapshot

Who can take Nucala?

Nucala is approved in the U.S. as an add-on maintenance treatment for adults with inadequately controlled COPD and an eosinophilic phenotype (meaning high eosinophil counts).

It is not recommended for anyone with a history of allergic reaction to the therapy or any of its ingredients.

The medication also should not be used to manage acute symptoms or acute exacerbations of COPD, or to treat acute bronchospasm (a tightening of lung muscles that narrows the airways, making it difficult to breathe).

How is Nucala administered in COPD?

Nucala is given by under-the-skin injections, which should be done under the guidance of a healthcare professional. The therapy’s prefilled autoinjector and prefilled syringe versions can be used by patients and their caregivers after appropriate training.

The recommended dosage for COPD is 100 mg every four weeks.

Nucala in clinical trials

Nucala’s approval in the U.S. was based on data from two Phase 3 clinical trials that collectively enrolled more than 1,600 adults with inadequately controlled COPD and an eosinophilic phenotype. Participants were randomly assigned to receive either Nucala or a placebo, in addition to standard triple inhaled therapy, consisting of a corticosteroid and two bronchodilators (medications that widen the airways), for one year.

Both studies showed that, relative to the placebo, one year of Nucala treatment significantly reduced annualized rates of moderate or severe exacerbations:

• by 21% in the MATINEE study (NCT04133909)
• by 18% in the METREX trial (NCT02105948).

In MATINEE, Nucala treatment was also associated with a significantly lower risk of moderate or severe exacerbation, by 23%, and a 35% lower annualized rate of exacerbations requiring emergency department visits and/or hospitalization.

In both MATINEE and METREX, patient-reported measures of life quality and symptom severity were not significantly different between the Nucala and placebo groups.

Nucala side effects

Most side effects observed with Nucala in people with COPD are mild to moderate in severity. The most common ones include:

• back pain
• diarrhea
• cough.

Nucala also may cause other safety issues including:

• allergic reactions
• higher susceptibility to infection with herpes zoster (the virus that causes chickenpox and shingles) and certain parasites called helminths or worms.

These may necessitate safety precautions like monitoring, pre-treatment vaccination, and Nucala treatment delay.

Also, corticosteroids should not be abruptly discontinued upon initiation of Nucala treatment, because it can cause dangerous reactions. Instead, dosage of corticosteroids should be gradually reduced under the guidance of a healthcare professional.

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