[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/) › Benralizumab

# Benralizumab

## Biologics for asthma?

Biologics for asthma

An antibody against the IL-5 receptor that removes eosinophils, used as add-on treatment in severe eosinophilic asthma and in EGPA.

Updated Nov 1, 2026

## Quick facts

**Group**
[Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/)

**Target**
Interleukin-5 receptor alpha chain (IL-5Rα)

**Used for**
Eosinophilic granulomatosis

**Key effects**
Headache · Sore throat · Injection-site reactions

**Monitor**
Blood eosinophil count · Exacerbations

**ATC**
R03DX10

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

◎**Interleukin-5 receptor alpha chain (IL-5Rα)**Benralizumab

ⓘ The figure shows IL-5 bound to the human IL-5 receptor alpha chain (crystal structure). Benralizumab binds this receptor chain; the antibody itself is not in the model.

**Target in 3D:** Interleukin-5 receptor alpha chain (IL-5Rα). PDB structure 3VA2 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3VA2) · Drag to rotate · pinch to zoom

Benralizumab is a humanised IgG1 monoclonal antibody against the alpha chain of the interleukin-5 receptor, which sits mainly on eosinophils. It blocks IL-5 signalling and, unlike the antibodies that only capture IL-5, it is cytolytic: it marks eosinophils for destruction, so they are depleted from blood and airway tissue. Exacerbations and the need for oral corticosteroids fall in eosinophilic asthma.

- Benralizumab binds IL-5 receptor alpha on eosinophils
- IL-5 can no longer signal through the receptor
- Bound eosinophils are destroyed and depleted
- Eosinophilic inflammation and flare-ups fall

## Indications

- Severe eosinophilic asthma not controlled by current treatment, as add-on maintenance in adults and children from six years [Asthma →](https://durgical.com/en/conditions/asthma/)
- Eosinophilic granulomatosis with polyangiitis (EGPA) in adults [Eosinophilic granulomatosis with polyangiitis (Churg–Strauss) →](https://durgical.com/en/conditions/eosinophilic-granulomatosis-with-polyangiitis/)

## Adverse effects

### Common

- Headache
- Sore throat
- Injection-site reactions

### Serious (rare, important)

- Hypersensitivity reactions: hives, rash, swelling of the face or tongue, breathing difficulty, fainting

## Contraindications

- Hypersensitivity to benralizumab
- Not for an acute asthma attack or bronchospasm
- A worm (helminth) infection is reported and treated first

## Key interactions

**Other asthma medicines, including corticosteroids**
Are not reduced or stopped without medical supervision

## What is monitored

- Blood eosinophil count (selection)
- Exacerbations and oral corticosteroid use
- Allergic reactions after injections

## Administration and safety

- Subcutaneous injection into the upper arm, thigh or abdomen, usually in a clinic
- An autoinjector may be used at home after training; each device is single-use
- Avoid the area around the navel and tender, bruised, red, hard or scarred skin

## Pregnancy and breastfeeding

Data in pregnancy are limited; antibodies cross the placenta, and use is decided with the specialist.

## Nursing care

- Ask about worm infections before starting
- Teach the signs of an allergic reaction
- Remind that it does not treat an attack: the rescue inhaler is still needed
- Other asthma medicines are not stopped on the patient's own

## Pharmacokinetics

**Absorption**
Subcutaneous injection

**Elimination**
Broken down like other antibodies (proteolysis)

**Onset and duration**
Blood eosinophils fall quickly; clinical benefit builds over months

## Memory aid

BENRAlizumab BANishes eosinophils: it hits the Receptor (IL-5Rα) and Removes the cell.

## Test yourself

Think of the answer, then tap the question to see it.

## What does benralizumab bind, and how is that different from mepolizumab?

The IL-5 receptor alpha chain on eosinophils; mepolizumab binds IL-5 itself.

## Why does benralizumab deplete eosinophils rather than just block them?

It is cytolytic: once bound, the eosinophil is destroyed.

## Which non-asthma condition is an indication for benralizumab?

Eosinophilic granulomatosis with polyangiitis (EGPA).

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/benralizumab/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Mepolizumab](https://durgical.com/en/pharmacology/mepolizumab/)
- [Reslizumab](https://durgical.com/en/pharmacology/reslizumab/)
- [Tezepelumab](https://durgical.com/en/pharmacology/tezepelumab/)

## Related conditions 2

- [Asthma](https://durgical.com/en/conditions/asthma/)
- [Eosinophilic granulomatosis with polyangiitis (Churg–Strauss)](https://durgical.com/en/conditions/eosinophilic-granulomatosis-with-polyangiitis/)

[← Back to the class: Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Benralizumab Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a618002.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [RCSB PDB - 3VA2: Crystal structure of human Interleukin-5 in complex with its alpha receptor](https://www.rcsb.org/structure/3VA2) (RCSB Protein Data Bank, 2012); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R03DX10) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/benralizumab/
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