What is severe asthma?

Asthma which requires the use of high dose inhaled corticosteroids (ICS) plus a second controller
(and/or systemic corticosteroids) to prevent it from becoming ‘uncontrolled’ or which remains
‘uncontrolled’ despite this therapy.
[1] (International European Respiratory Society [ERS] and American Thoracic Society [ATS] Task Force.)


Patients with refractory disease either remain uncontrolled despite their treatment being optimised or require high doses of controller and reliever medication to maintain control. [2]


The eosinophilic asthma phenotype has been shown to be associated with asthma severity, late-onset disease and steroid refractoriness. [4]


By characterising a patient’s severe asthma phenotype, they can be treated differently with personalised and targeted therapies, and outcomes could be improved. [4]

Nucala is an anti-IL-5 treatment that specifically targets the eosinophilic phenotype. [5]

Prevalence and burden

Severe asthma patients are at high risk of having a severe exacerbation and are often dependent on oral corticosteroids.[4]

These patients account for 50% of healthcare resource utilisation and have few therapeutic options available. [2], [4]

Nucala is an anti-IL-5 treatment that specifically targets the eosinophilic phenotype.


  1. Chung KF, Wenzel SE, Brozek JL et al. Eur Respir J 2014;43:343–373.
  2. Peters S P, Ferguson G, Deniz Y et al. Respir med 2006;100:1139–1151.
  3. Walford H et al. E Journal Asthma Allergy 2014;11(7): 53-56
  4. Hoskins G, McCowan C, Neville RG. et al. Thorax 2000;55:19–24.
  5. Campo P, Rodriguez F, Sánchez-García et al. J Investig Allergol Clin Immunol 2013;23:76–88.
  6. Nucala Summary of Product Characteristics. Available from www.medicines.ie Last accessed: May 2020
  7. Walford H, Doherty T. J Asthma Allergy 2014;11:53–65.

Nucala is a registered trademark of the GlaxoSmithKline Group of Companies