Fasenra (Benralizumab) is a maintenance treatment given to people with eosinophilic asthma. It is not a rescue medication; instead, it is an add-on treatment, and is used alongside other asthma treatments to control symptoms 1.

How Fasenra Works

Fasenra works by targeting and removing the cells that play a key role in asthma 2. Eosinophilic asthma is characterised by large numbers of eosinophils, white blood cells that cause inflammation and can trigger asthmatic symptoms.

The active ingredient in Fasenra (Benralizumab) attaches to receptors on the surface of eosinophils and triggers the body’s immune system to attack them. This reduces the number of eosinophils in the bloodstream, reducing inflammation and improving symptoms as a result.

When used in combination with other asthma treatments, Fasenra has been clinically proven to improve lung function, prevent asthma attacks and reduce or even stop oral steroid use in asthma patients 3.

Fasenra Clinical Trials & Drug Effectiveness

Fasenra has performed well in clinical trials studies.

Two similarly-designed trials 4 (CALIMO and SIROCCA) compared the effects of Benralizumab with a placebo in eosinophilic asthma patients and found that lung function and symptoms were both improved by treatment with Benralizumab.

A third clinical trial (ZONDA) demonstrated that treatment with Benralizumab reduced asthma patient’s reliance on oral steroids, and reduced the mean steroid dose by more than 50% compared with the placebo.

How Fasenra Is Administered & Dose Information

Fasenra is intended for add-on maintenance treatment of patients with severe eosinophilic asthma over the age of 12 years 5. The drug is administered via subcutaneous injection, and the recommended dose is 30mg every 4 weeks for the first three doses, followed by 30mg every 8 weeks thereafter.

Fasenra may be injected by a healthcare professional, or by the patient once training has been provided.

Fasenra Side Effects & Safety

As is the case with all medications, Fasenra can cause side effects which may be mild or severe 6.

Common side effects of taking Fasenra include:

  • Headache
  • Sore throat
  • Fever
  • Injection site reactions (such as pain, redness, itching or a small lump)

In most cases, these side effects will subside by themselves. If your headache or sore throat doesn’t go away or becomes more severe, consult your doctor to discuss potential treatments.

You should also contact your doctor if you have a fever lasting more than 3 days or a temperature higher than 103°F (39.4 °C).

Serious side effects of taking Fasenra include:

Some people may have an allergic reaction to Fasenra, although this is rare 7. Allergic (or hypersensitivity) reactions to Fasenra may cause the following symptoms:

  • Difficulty breathing
  • Swelling of the face, mouth and tongue
  • Low blood pressure (causing fainting, dizziness and light-headedness)
  • Rash
  • Hives

In severe cases, Fasenra can trigger anaphylaxis, for which these symptoms can be life threatening. If you experience symptoms of allergic reaction after taking Fasenra contact your doctor immediately, or call 911 for emergency assistance.

How Much Does Fasenra Cost and Is It Covered By Medicare?

Fasenra costs $4895.74 per 30ml dose 8.

If you have Original Medicare Part B insurance, you will likely be expected to pay 20% of this amount, provided you visit a facility that accepts assignment. If you have the Medicare Advantage Plan, your insurance may include additional coverage.

Contact your health insurance provider for more information.

Current Eosinophilic Asthma Clinical Trials

At Clara Health, we have our own patient-focused database for Current Eosinophilic Asthma Clinical Trials to help you match with a study that best fits your life situation!

Quick Facts About Eosinophilic Asthma

What is Asthma?

Asthma is a cluster of diseases characterized by the narrowing and swelling of the airways 9. This triggers an asthma ‘attack’ (or flare-up) and causes shortness of breath, wheezing, coughing and difficulty breathing.

For a long time, asthma was thought to be a single condition, but we now know there are lots of different types of asthma. Eosinophilic asthma has been identified as a subtype of asthma 10.

How is Eosinophilic Asthma Different From Regular Asthma?

Eosinophilic asthma is a rare subtype of asthma, and often causes severe symptoms.

In patients with eosinophilic asthma, the inflammation of their airways is caused by abnormally high levels of white blood cells called eosinophils 11. This is different to other forms of asthma, which are more commonly triggered by environmental factors, such as dust, pollen or animal hair.

Unlike other types of asthma, eosinophilic asthma cannot be treated using inhaled corticosteroids. Biologic medications (such as Fasenra) must be used instead.

How Common Is Eosinophilic Asthma?

Eosinophilic asthma is rare among the general population 12, and is only thought to affect around 5% of the estimated 25.7 million adults with asthma in the US.

However, it is considered a leading cause of severe asthma, and is thought to affect 50 - 60% of people with a severe form of the condition.

Who is Most Likely to be Affected by Eosinophilic Asthma?

Eosinophilic asthma is a rare subtype of severe asthma that is most commonly seen in adults 13. Most people with the condition first start to notice symptoms between the ages of 35 and 50 years old, at which point they will often show elevated blood and tissue levels of eosinophils.

Though the condition usually affects adults, eosinophilic asthma may also develop in children, adolescents and young adults. Eosinophilic asthma seems to affect men and women equally.

What Causes Eosinophilic Asthma?

The exact causes of eosinophilic asthma are still unknown 14, as patients with the condition do not have the underlying allergies that usually trigger asthma symptoms (such as pollen, pet hair, dust mites and smoke).

How is Eosinophilic Asthma Diagnosed?

If you think you may have eosinophilic asthma, your doctor will first ask you to describe your symptoms, as well as your personal and family medical history. They may also perform diagnostic tests of your blood, sputum or respiratory tissues 15.

Eosinophilic asthma is characterized by abnormally high levels of eosinophils in the blood and respiratory tissues. Therefore, diagnosis is usually confirmed via blood test.

About Clara Health

Clara Health is a patient-centric healthcare platform that was founded to assist patients in finding relevant research studies & clinical trials. At Clara, it is our core belief that each and every patient should have the ability to access the most advanced healthcare treatments currently available and we are on a mission to make this process as seamless as possible.

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1"What is Fasenra used for and how does it work? - Drugs.com." 19 May. 2020, https://www.drugs.com/medical-answers/fasenra-work-3541067/.

2"Fasenra medicine overview update II-14G - European ...." https://www.ema.europa.eu/documents/overview/fasenra-epar-medicine-overview_en.pdf.

3"FASENRA FAQs | FASENRA® (benralizumab) for Severe ...." https://www.fasenra.com/faq.html.

4"Discussion - Clinical Review Report: Benralizumab (Fasenra ...." https://www.ncbi.nlm.nih.gov/books/NBK541777/.

5"Fasenra - Indian Pharma Network." http://indianpharmanetwork.in/FASENRA.pdf.

6"Fasenra: Side effects, dosage, alternatives, and more." https://www.medicalnewstoday.com/articles/fasenra.

7"Fasenra (Benralizumab): Asthma Uses, Dosage, Side Effects ...." https://www.rxlist.com/fasenra-drug.htm.

8"Does Medicare Cover Fasenra? - Medicare.org." https://www.medicare.org/articles/does-medicare-cover-fasenra/.

9"Asthma - Symptoms and causes - Mayo Clinic." 11 Aug. 2020, https://www.mayoclinic.org/diseases-conditions/asthma/symptoms-causes/syc-20369653.

10"Eosinophilic Asthma: What It Is and What Makes It Different." 7 Jan. 2020, https://www.webmd.com/asthma/eosinophilic-asthma-causes.

11-12"What to know about eosinophilic asthma - Medical News Today." 20 Sep. 2017, https://www.medicalnewstoday.com/articles/319466.

12-15"Eosinophilic Asthma | Apfed." https://apfed.org/about-ead/eosinophilic-asthma/.