Pharmacologic class (EPC) · 2 drug pages

Interleukin-5 receptor alpha-directed cytolytic antibody: adverse event reports filed with FDA

18,460 reports list a drug in this class as a suspect or interacting product, 2012–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

18,460
reports across the class: 0.1% of all reports; 3,553
reports, 12 months to June 2026: 3,863 in the 12 months before; 65.3%
marked serious by the reporter: 57.4% across all reports; 2
drugs with a page: brand and generic names counted separately

Interleukin-5 receptor alpha-directed cytolytic antibody is a pharmacologic class (an FDA Established Pharmacologic Class) with 2 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 18,460 adverse event reports received by FDA, 0.1% of the database, from November 2012 to June 2026.

3,553 reports arrived in the 12 months to June 2026, close to the 3,863 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 65.3% of the class's reports are marked serious, 10.6% record death among the outcomes and 24.4% record hospitalisation, as reported.

Across the class the reactions recorded most often are asthma (14.9%), dyspnoea (10%) and death (8.8%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
FasenraBenralizumab	brand	14,436	1,492	56.4%	Asthma
Benralizumab	generic	4,024	2,061	97.3%	Asthma

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Asthmaasthma14.9%2,748
Dyspnoeashortness of breath10%1,847
Deaththe patient died; cause not stated by this term8.8%1,619
Drug ineffectivethe medicine did not work as expected7.5%1,379
Pneumonialung infection5.4%993
Coughcough5%929
Product dose omission issuea dose was missed5%920
Headachehead pain4.7%866
Wheezingwheezing3.8%705
Malaisegeneral feeling of being unwell3.1%579
Fatiguetiredness3%548
Inappropriate schedule of product administrationthe product was taken at the wrong times2.9%536
Pyrexiafever2.7%491
Arthralgiajoint pain2.6%476
Rashskin rash2.5%464
Painpain, site not specified2.4%438
Device leakagethe device leaked2.3%422
Dizzinesslight-headedness or unsteadiness2.2%414
Covid-19COVID-19 infection2.2%406
Hypersensitivityan allergic-type reaction2.2%403
Pruritusitching2.2%403
Condition aggravatedthe condition being treated got worse2.1%392
Urticariahives2.1%383
Chest discomfortchest discomfort2%371
Falla fall2%363

Solid bar: share of all class reports. Hollow bar: the median share across the 2 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death10.6%1,962

Life-threatening2.2%399

Hospitalisation (initial or prolonged)24.4%4,498

Disability1.1%199

Congenital anomaly0.1%22

Other serious39.9%7,363

Not serious34.7%6,410

Patient age

Under 20%8

2 to 110.1%18

12 to 170.5%94

18 to 446.5%1,197

45 to 6415.9%2,944

65 to 749.6%1,765

75 and over7.7%1,429

Age not given59.6%11,005

Who reported

Physician26.6%4,903

Pharmacist2.1%387

Other health professional14.8%2,733

Lawyer0%0

Consumer or non-health professional51.6%9,527

Not given4.9%910

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Interleukin-5 receptor alpha-directed cytolytic antibody reports

Which drugs are in the Interleukin-5 receptor alpha-directed cytolytic antibody class on this site?

Fasenra and Benralizumab. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

18,460 reports through June 2026, 3,553 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

asthma (14.9%), dyspnoea (10%), death (8.8%), drug ineffective (7.5%) and pneumonia (5.4%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.