Skip to main content

What is Fasenra used for and how does it work?

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 4, 2024.

Official answer

by Drugs.com

Fasenra injection may be used to treat severe eosinophilic asthma in adults and children aged 6 years and older or eosinophilic granulomatosis with polyangiitis (EGPA) in adults.

Fasenra's mechanism of action (MOA) involves specifically targeting eosinophils, which are white blood cells associated with inflammation found in the airways of people with asthma and tissues of people with EGPA. Fasenra binds to interleukin receptor (IL-5Ra) found on the surface of eosinophils which blocks the effects of interleukin 5, a cytokine that is crucial for eosinophil development. Cytokines are small secreted proteins that are involved in cell signaling and interactions. By binding to IL-5, Fasenra reduces the production and survival of eosinophils, reducing the number of eosinophils in tissues and the blood. Eosinophils play a key role in inflammation and certain conditions such as asthma, EGPA, cancer, and parasitic infections..

Fasenra also binds to and activates another receptor called FcγRIIIa found on natural killer (NK) cells (also a type of white blood cell). This enhances the programmed cell death of eosinophils via a process called antibody-dependent cell-mediated cytotoxicity (ADCC). It also enhances the apoptosis of basophils. Basophils are yet another type of white blood cell that also play a role in the airway inflammation associated with asthma.

Fasenra may also be called a biologic. Fasenra belongs to the drug class Interleukin inhibitors.

Related questions

Fasenra mechanism of action summary

Fasenra is a monoclonal antibody that has a targeted approach. Fasenra works by:

  • Depleting the number of eosinophils
  • Blocking IL-5 from binding to eosinophils, which prevents IL-5 from helping eosinophils to multiply and survive
  • Enhancing the ability of natural killer (NK) cells to kill eosinophils
  • Enhancing the ability of NK cells to kill basophils, which also play a role in the airway-inflammation associated with asthma and tissue inflammation in EGPA.

References

Read next

What eosinophil count is needed for Fasenra?

Fasenra may be an option for severe asthma if you have an eosinophil count of at least 150-300 cells per microliter (cells/μL), determined from a common blood test, plus you have required an oral corticosteroid treatment (like prednisone) at least twice per year, despite maximum inhalation therapy. 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

What is considered severe asthma?

Severe asthma is when you require medium to high-dose inhaled corticosteroids combined with other longer-acting medications. Severe asthma can also be defined as having a peak expiratory flow rate (PEF or PEFR) less than 50% of your personal best. This shows severe narrowing of your large airways and is considered a medical emergency and you should get help right away. Your symptoms may include coughing, being very short of breath, wheezing while breathing in and out, or retractions (this is when you can see the muscles between the ribs working hard to keep you breathing). Walking and talking may also be difficult. Continue reading

Related medical questions

Drug information

Related support groups