Skip to Accessibility Tools Skip to Content Skip to Footer

Fasenra (benralizumab)


Fasenra (benralizumab) is a monoclonal antibody indicated for individuals aged 12 years and older with severe eosinophilic asthma. Fasenra is indicated for use as an add-on maintenance treatment. Fasenra is administered as a subcutaneous (under the skin) injection. Individuals taking Fasenra should be monitored for signs of hypersensitivity (allergic) reactions, such as rash or difficulty breathing. Individuals taking Fasenra, who are also taking corticosteroids, should not discontinue or reduce the dose of their corticosteroids without the prior approval of their healthcare provider.

What are the ingredients in Fasenra?

The active ingredient in Fasenra is benralizumab, the monoclonal antibody.

How does Fasenra work?

Fasenra’s active ingredient binds to a cytokine called IL-5, blocking it from binding to the IL-5 receptor complex located on eosinophils. This action then targets the eosinophil for destruction by the body’s natural killer cells. Eosinophils are white blood cells that are present in healthy immune systems. These blood cells aid in combatting parasites and infections. Elevated levels of these cells, like in severe eosinophilic asthma, can cause abnormal functioning of the immune system, leading to airway inflammation, impaired lung functioning, increased risk of exacerbations, increased asthma severity and symptoms, and airway hyper-responsiveness. By destroying excess eosinophils, inflammation leading to eosinophilic asthma symptoms may be reduced. This mechanism begins quickly, with an onset of action occurring within the first 24 hours of receiving the medication.

What are the possible side effects of Fasenra?

Multiple clinical trials evaluated the safety and efficacy of Fasenra. The most common side effects of Fasenra include headache and sore throat. This is not an exhaustive list of all potential side effects of Fasenra. Talk to your healthcare provider or pharmacist for further information.

Things to note about Fasenra

Serious hypersensitivity (allergic) reactions can happen after receiving a Fasenra injection. Alert your provider immediately or seek immediate medical attention if you notice any of the following signs of an allergic reaction:

  • Breathing problems
  • Rash
  • Hives
  • Fainting, feeling lightheaded, dizziness
  • Swelling of mouth, face, or tongue

Additionally, individuals with parasitic (helminth) infections should be treated for their infection before starting Fasenra. Treatment should be discontinued if a helminth infection that does not respond to anti-helminth treatment arises. Further, individuals taking corticosteroids of any kind should not stop or change their corticosteroid dosage without talking to their provider first.

Before staring Fasenra talk to your healthcare provider if you:

  • Are taking inhaled or oral corticosteroids
  • Have or have previously had a helminth (parasitic) infection
  • Are pregnant or planning to become pregnant
  • Are breastfeeding or planning to breastfeed
  • Are taking any other medications, including over-the-counter medications
  • Are taking any vitamins or herbal supplements
  • Use with caution in patients with hamster protein hypersensitivity

Dosing information

Fasenra is administered via a subcutaneous (under the skin) injection by a healthcare provider. A typical dosage is 30 mg of Fasenra once every four weeks for the first three doses, and then once every eight weeks thereafter.1

Written By: Casey Hribar | Last Reviewed: September 2019.
  1. Fasenra Prescribing Information. AstraZeneca. Published November 2017. Accessed November 26, 2017.