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Prescription medication · Anti-IL-5R Monoclonal Antibody

benralizumab

Also sold as Fasenra. Fasenra is used to treat severe asthma in adults and children 6 years and older when used with other asthma medicines.

Data updated 2026-05-15

17,680
FDA reportsModerately reported
Rx
Availability

benralizumab (Fasenra) is a prescription Anti-IL-5R Monoclonal Antibody. Fasenra is used to treat severe asthma in adults and children 6 years and older when used with other asthma medicines.

Fasenra is a medicine that can help treat severe asthma and EGPA. It works by lowering the number of eosinophils in your blood, which can reduce swelling in your lungs and blood vessels.

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What it does

Fasenra is used to treat severe asthma in adults and children 6 years and older when used with other asthma medicines.

Common side effects

Headache, Sore throat, Fever

Key warnings

Serious allergic reactions can happen after you get a Fasenra shot.

The sections below are summarized in plain English from benralizumab's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Fasenra is a special type of antibody that targets a protein called interleukin-5 receptor alpha (IL-5Rα). This protein is found on the surface of eosinophils. By attaching to this protein, Fasenra helps to lower the number of eosinophils in your blood.

How to Take It

Fasenra is given as a shot under the skin (subcutaneous injection). For asthma, adults and children 6 years and older usually get a 10mg or 30mg injection every 4 weeks for the first 3 doses. After that, you will get a shot once every 8 weeks. For EGPA, adults get a 30mg injection once every 4 weeks.

This is a plain-language summary of benralizumab's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.

Pregnancy & Breastfeeding

There is not enough information to know if Fasenra will harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if Fasenra passes into breast milk. Talk to your doctor about the best way to feed your baby if you are taking Fasenra.

This is a plain-language summary of benralizumab's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.

Missed Dose

If you miss a dose of Fasenra, call your doctor right away to reschedule your injection. Do not double your next dose.

This is a plain-language summary of benralizumab's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.

Storage

Store Fasenra in the refrigerator between 36°F and 46°F (2°C and 8°C) in its original carton to protect it from light.

Side Effects (from patient reports)

Based on 17,680 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for benralizumab, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS) As of 2025

Reports over time

Adverse-event reports filed for benralizumab each year to the FDA Adverse Event Reporting System (FAERS).

-1,00001,0002,0003,0004,000 20122014201620182020202220242025 3,507

Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.

Where benralizumab sits

benralizumab has more FDA adverse-event reports than 52% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.

fewest reports most reports

Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is benralizumab; the line is the median (50th percentile).

FDA Adverse Event Report Analysis

Detailed analysis of 17,680 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2012–2025.

Total Reports

17,680

Reports Mentioning Death

1,749

9.9% of reports — not proof of cause

Hospitalization Reports

4,130

Top Indication

Asthma

Gender Distribution

Female 11,037 (70%)
Male 4,811 (30%)

Age Distribution

0–17 104
18–44 876
45–64 1,909
65–74 1,097
75+ 814

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 ASTHMA 2,775
2 DYSPNOEA 1,802
3 DEATH 1,437
5 COUGH 944
6 HEADACHE 874
8 PNEUMONIA 823
9 WHEEZING 692
10 FATIGUE 592
11 MALAISE 565
12 INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION 536
13 ARTHRALGIA 515
14 PYREXIA 510
15 RASH 486
16 PAIN 459
17 COVID-19 440

Reactions in Death Reports

DEATH 1,434
PNEUMONIA 45
ASTHMA 42
COVID-19 26
RESPIRATORY FAILURE 22
DYSPNOEA 20
CARDIAC ARREST 19
MYOCARDIAL INFARCTION 16
FALL 13
ABORTION SPONTANEOUS 12

Reactions in Hospitalization Reports

ASTHMA 1,048
DYSPNOEA 536
PNEUMONIA 464
COUGH 217
WHEEZING 180
COVID-19 175
PYREXIA 172
INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION 171
MALAISE 170
FALL 157

Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

Serious allergic reactions can happen after you get a Fasenra shot. Tell your doctor right away if you have any signs of an allergic reaction, such as hives, swelling, or trouble breathing. Do not stop taking your steroid medicines suddenly when you start Fasenra. Your doctor will lower your steroid dose slowly, if needed. If you have a parasitic infection, it should be treated before you start Fasenra.

Common Questions

What should I tell my doctor before taking Fasenra?
Tell your doctor if you are allergic to benralizumab or any of the other ingredients in Fasenra. Also, tell them if you have a parasitic infection or are taking steroid medicines.
Can Fasenra be used for sudden asthma attacks?
No, Fasenra is not a rescue medicine. It will not help with sudden asthma symptoms or attacks.
How will I know if Fasenra is working?
You may notice that you have fewer asthma symptoms or EGPA symptoms. Your doctor will also monitor your condition to see how well the medicine is working.
Can I stop taking my other asthma medicines while using Fasenra?
Do not stop taking your other asthma medicines unless your doctor tells you to. Fasenra is used in addition to your other medicines.
How is Fasenra given?
Fasenra is given as a shot under the skin (subcutaneous injection) by a healthcare provider or by yourself/caregiver if properly trained.
What if I have side effects from Fasenra?
Tell your doctor about any side effects you have while taking Fasenra. They may be able to help you manage them.
How long will I need to take Fasenra?
You will likely need to take Fasenra for a long time to control your asthma or EGPA. Talk to your doctor about how long you should continue taking it.
Can children take Fasenra?
Yes, Fasenra can be used in children 6 years and older with severe eosinophilic asthma.
What does Fasenra look like?
Fasenra is a clear to slightly yellow liquid. It may have a few tiny particles in it.
Can I travel with Fasenra?
Yes, but make sure to keep it refrigerated. If needed, it can be stored at room temperature for up to 14 days.
What are the common side effects of benralizumab?
The most commonly reported side effects of benralizumab include Headache, Sore throat, Fever. Based on 17,680 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
What drug class is benralizumab?
benralizumab belongs to the Anti-IL-5R Monoclonal Antibody drug class. It requires a prescription (Rx). Fasenra is used to treat severe asthma in adults and children 6 years and older when used with other asthma medicines.
Is benralizumab safe during pregnancy?
There is not enough information to know if Fasenra will harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

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What the FDA Data Shows for benralizumab

The FDA label for benralizumab (sold under brand names such as Fasenra) classifies it as a prescription-only medication in the Anti-IL-5R Monoclonal Antibody class. Fasenra is used to treat severe asthma in adults and children 6 years and older when used with other asthma medicines. Official labeling lists 3 commonly reported side effects, including Headache, Sore throat, Fever.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 17,680 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: September 17, 2024

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.

All federal data sources used on this page