How long does it take for Nucala to work?

Medically reviewed by Carmen Pope, BPharm. Last updated on May 28, 2025.

Official Answer by Drugs.com

Nucala starts working within 48 hours; however, it may take up to 4 weeks before the maximum effect of Nucala is seen for both asthma and eosinophilic granulomatosis with polyangiitis (EGPA). In asthma, the greatest reductions in eosinophils were seen with higher dosages, for example, a 64% reduction in eosinophils was seen with a 12.5mg SC dose and a 90% reduction was seen with a 250mg SC dose after 48 hours. When used to treat COPD, Nucala reduced the number of yearly COPD exacerbations compared to placebo (an inactive treatment).

Nucala (mepolizumab) is a biologic that is administered by subcutaneous injection once every four weeks.

It is approved as:

As an add-on maintenance treatment for severe eosinophilic asthma in adults and children aged 6 and older
For inadequately controlled chronic obstructive pulmonary disease (COPD) with an eosinophilic phenotype in adults as add-on maintenance treatment
For the treatment of adult patients with eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
For the treatment of patients ≥12 years with hypereosinophilic syndrome (HES)
As an add-on maintenance treatment of chronic rhinosinusitis with nasal polyps (CRwNP) in adult patients 18 years of age and older with inadequate response to nasal corticosteroids.an add-on maintenance treatment for severe eosinophilic asthma in adults and children aged 6 and older.

In trials of people with eosinophilic asthma:

Reductions in blood eosinophils were seen within 48 hours of a dose of mepolizumab for all treatment doses
Greater eosinophil reductions were seen with higher mepolizumab dosages, for example, 64% with a 12.5mg SC dose, 78% for a 75mg dose, and 90% with a 250mg SC dose
After treatment with Nucala 100mg SC every 4 weeks, blood eosinophils showed an average reduction of 84% (down to 40 cells/mcL) in adults
After treatment with Nucala 40mg SC every 4 weeks, blood eosinophils showed an average reduction of and 85% (down to 48 cells/mcL) in children aged 6 to 11 years.
The greatest effect was seen after 4 weeks of treatment and this was maintained throughout the treatment period.

In trials of people with EGPA blood eosinophil levels were reduced by 83% (down to 38 cells/mcL) with mepolizumab 300mg every 4 weeks.

Can Nucala be self-administered? How is it injected?

Yes, Nucala can be self-administered. Nucala is available as a prefilled syringe or autoinjector that can be self-administered after a doctor has shown you how to administer it. 99% of people can successfully self-administer the Nucala prefilled syringe and 89-95% can successfully administer the Nucala autoinjector.

What is Nucala (mepolizumab) used for and how is it given?

Nucala (mepolizumab) is a biologic therapy used for the treatment of severe eosinophilic asthma, eosinophilic granulomatosis with polyangiitis (EGPA), and hypereosinophilic syndrome (HES). It is given by subcutaneous injection every four weeks. Continue reading

Can severe asthma lead to COPD?

Severe and poorly controlled asthma can lead to damaged lungs which may increase the risk of developing chronic obstructive pulmonary disease (COPD). Symptoms of asthma and COPD may frequently co-exist in smokers and the elderly. Continue reading

How long does it take for Nucala to work?

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Can Nucala be self-administered? How is it injected?

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