Pronunciation: fas-en-rah
Generic name: benralizumab
Dosage form: injection for subcutaneous use
Drug class: Interleukin inhibitors

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 3, 2024.

What is Fasenra?

Fasenra (benralizumab) is an injectable monoclonal antibody that may be used as add-on therapy to treat severe eosinophilic asthma in adults and children aged 6 years and older. Fasenra is also approved to treat eosinophilic granulomatosis with polyangiitis (EGPA) in adults.

Fasenra's mechanism of action specifically targets eosinophils, which are white blood cells associated with inflammation found in the airways of people with asthma, and the tissues of people with EGPA. Fasenra binds to a protein called interleukin receptor 5Ra (IL-5Ra) on the surface of eosinophils, enhancing the action of natural killer cells from the immune system, which release cytotoxic substances that cause cell death. This MOA of Fasenra depletes eosinophils in tissues and the blood, and reduces inflammation. For more information see What is Fasenra used for and how does it work?

Fasenra first gained FDA approval on November 14, 2017, for eosinophilic asthma. Fasenra's approval was extended to include EGPA on September 17, 2024.

Fasenra side effects

The most common side effects of Fasenra are headache and sore throat.

Serious side effects and warnings

Fasenra may cause serious side effects, including:

Allergic (hypersensitivity) reactions, including anaphylaxis. Serious allergic reactions can happen after you get your Fasenra injection. Allergic reactions can sometimes happen hours or days after you get your injection. Tell your healthcare provider or get emergency help right away if you have any of the following symptoms of an

• allergic reaction:
• swelling of your face, mouth, and tongue
• breathing problems
• fainting, dizziness, feeling lightheaded (low blood pressure)
• rash
• hives.

Fasenra should not be given for eosinophilic asthma to a child younger than 6 years old or for EGPA to an adolescent or child under the age of 18. 

Fasenra is not a rescue medicine for asthma attacks. Use only fast-acting inhalation medicine for an attack. Seek medical attention if your fast-acting medicine does not work.

These are not all the possible side effects of Fasenra. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA1088.  

Fasenra cost

Eligible commercially insured patients with a valid prescription for Fasenra who enroll in the Fasenra 360 Savings Program may pay as little as $0 per administration of Fasenra dependent upon the patient’s prescription coverage of Fasenra (see here for the Fasenra enrollment form).

• Fasenra is covered for 87% of commercially insured patients with an eosinophil count of at least 150 cells/microliter. 

For people with Medicare Advantage plans, the average out-of-pocket cost is $90 per dose. This represents about one-third of all people with Medicare.

See here for the full cost of Fasenra for those without an eligible insurance plan. This cost may vary depending on dosage and the pharmacy you use.

Before taking this medicine

Do not receive a Fasenra injection if you are allergic to benralizumab, Fasenra, or any inactive ingredients in the injection.

Before receiving Fasenra, tell your healthcare provider about all of your medical conditions, including
if you:

• have any allergies
• are taking oral or inhaled corticosteroid medicines. Do not stop taking your corticosteroid medicines unless instructed by your healthcare provider. This may cause other symptoms that were controlled by the corticosteroid medicine to come back
• have a parasitic (helminth) infection (such as pinworms, roundworms or tapeworms)
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Before you start treatment with Fasenra, your doctor may perform tests to measure your eosinophil levels.

Do not stop taking your other medicines for your condition unless your healthcare provider tells you to.  

Pregnancy

It is not known if Fasenra will harm your unborn baby. Tell your healthcare provider if you become pregnant during your treatment with Fasenra.

Breastfeeding

It is not known if Fasenra passes into your breast milk. You and your healthcare provider should decide if you will use Fasenra and breastfeed. Talk to your healthcare provider about the best way to feed your baby if you use Fasenra.

How do I use a Fasenra injection?

Do not try to inject Fasenra until you have been shown the right way by your healthcare provider. See
the detailed “Instructions for Use” that comes with the Fasenra Pen for information on how to prepare and inject your Fasenra injection.

Fasenra is injected under your skin (subcutaneously [SC]):

• one time every 4 weeks for the first 3 doses and then every 8 weeks, for asthma.
• one time every 4 weeks for EGPA.

Fasenra comes as a single-dose prefilled syringe and a single-dose autoinjector (Fasenra Pen).

• A healthcare provider uses a single-dose prefilled syringe to inject Fasenra.

If your healthcare provider decides that you or a caregiver can give the Fasenra Pen you or your caregiver should receive training on the right way to prepare and give the Fasenra injection using the Fasenra Pen.

• In people aged 6 to 11 years, Fasenra should only be given by a caregiver or healthcare provider.

If you are giving yourself the Fasenra injection, the recommended injection site is the front of your thigh or the lower part of your stomach (abdomen).

• A caregiver may inject you in the upper arm, thigh, or abdomen. Do not try to inject yourself in the arm.

For each injection, choose a different site that is at least 1 inch (3 cm) away from where you last injected. Do not inject:

• into the 2-inch (5-cm) area around your bellybutton
• where the skin is tender, bruised, scaly or hard
• into scars or damaged skin
• through clothing.

Fasenra is not a rescue medicine for asthma attacks. Use only fast-acting inhalation medicine for an attack. Seek medical attention if your fast-acting medicine does not work.

You may need frequent medical tests to help your doctor determine how long to treat you with Fasenra.

Fasenra dosing information

Fasenra dosage for asthma for adults and adolescents 12 years and older: 

• Fasenra 30 mg SC one time every 4 weeks for the first 3 doses, then one time every 8 weeks thereafter.

Fasenra dosage for asthma for children aged 6 through 11 years

• Weighing less than 35 kg: Fasenra 10 mg SC one time every 4 weeks for the first 3 doses followed by one time every 8 weeks thereafter.
• Weighing 35 kg or more: Fasenra 30 mg SC one time every 4 weeks for the first 3 doses followed by one time every 8 weeks thereafter.

Fasenra dosage for EGPA (eosinophilic granulomatosis with polyangiitis) for adults

• Fasenra 30 mg SC one time every 4 weeks.

Related/similar drugs

prednisone, Breo Ellipta, Dupixent, Xopenex, Atrovent, Dulera, Nucala, benralizumab, mepolizumab

What happens if I miss a dose?

If you miss a dose of Fasenra, call your healthcare provider. 

What happens if I overdose?

Since this medicine is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid while receiving Fasenra?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect Fasenra?

Other drugs may interact with benralizumab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

See the Fasenra Prescribing Information for a list of drug interactions.

Fasenra storage

Store Fasenra in a refrigerator between 36°F to 46°F (2°C to 8°C) in its original carton until you are ready to use it.

Fasenra may be kept at room temperature between 68°F to 77°F (20°C to 25°C) for a maximum of 14
days.

Once removed from the refrigerator and brought to room temperature, Fasenra must be used within
14 days or thrown away (disposed of).

Do not use your Fasenra Pen if:

• it has been frozen
• it has been dropped or damaged
• the security seal on the carton has been broken
• the expiration date (EXP) has passed

Do not 

• shake your Fasenra Pen.
• share or reuse your Fasenra Pen
• expose your Fasenra Pen to heat.

If any of these happen, throw away the Fasenra Pen in a puncture-resistant sharps disposal container
and use a new Fasenra Pen.

Each Fasenra Pen contains 1 dose of Fasenra that is for one time use only.

Keep all medicines out of the sight and reach of children. 

Fasenra ingredients

Active ingredient: benralizumab
Inactive ingredients: L-histidine, L-histidine hydrochloride monohydrate, polysorbate 20, α,α-trehalose
dihydrate, and Water for Injection.

Fasenra injection is available as:

• Fasenra 10 mg/0.5 mL solution in a single-dose prefilled syringe
• Fasenra 30 mg/mL solution in a single-dose prefilled syringe
• Fasenra 30 mg/mL solution in a single-dose autoinjector Fasenra Pen.

Who makes Fasenra?

AstraZeneca AB makes Fasenra.

Fasenra Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There is 1 for Fasenra.

Popular FAQ

More FAQ

• What type of asthma is Fasenra used to treat?

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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