Drug · FAERS side-effect profile with label screen
Benralizumab side effects: what 19,854 FDA adverse event reports show
Drug class
Interleukin-5 Receptor alpha-directed Cytolytic Antibody
FDA label (Established Pharmacologic Class)
Brand names
Fasenra
openFDA label
Who reports
19,854 reports · 64% serious · 2,002 with death outcome · 70% female
openFDA FAERS counts, all years, deduplication not applied
Used for
FASENRA is an interleukin-5 receptor alpha-directed cytolytic monoclonal antibody (IgG1, kappa) indicated for: • add-on maintenance treatment of adult and pediatric patients aged 6 years and older with severe asthma, and with an eosinophilic phenotype. ( 1.1 ) • treatment of adult patients with eosinophilic granulomatosis with polyangiitis (EGPA).
FDA label, Indications and Usage
What it is
Benralizumab is a humanized monoclonal antibody (IgG1/κ-class) selective for interleukin-5 receptor alpha subunit (IL-5Rα). Benralizumab is produced in Chinese hamster ovary cells by recombinant DNA technology. Benralizumab has a molecular weight of approximately 150 kDa.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled (related wording) 1Likely indication confounding 14Reporting / coding artifact 5Lab value / disease marker 4Not in label — unassessed 16
What the badges mean
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 990 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Eosinophilic otitis media | 11 | 497.0 242.3–1,019.4ROR 497.3 · χ² 3,355 / p <1e-300 | 212.7 EB05 126.8 · IC025 +3.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=11 | not reported in cached trials |
| Fev1/fvc ratio decreased | 10 | 95.3 49.9–182.2ROR 95.4 · χ² 771 / p 6e-170 | 75.3 EB05 43.7 · IC025 +3.0 3/3 methods agree | Lab value / disease marker | serious n=8 | not reported in cached trials |
| Eosinophilic granulomatosis with polyangiitis | 167 | 95.0 81.2–111.3ROR 95.8 · χ² 14,153 / p <1e-300 | 86.3 EB05 75.9 · IC025 +5.9 3/3 methods agree | Likely indication confounding term in indications | serious n=167 · 91% clinician | not reported in cached trials |
| Eosinophil count abnormal | 59 | 90.6 69.4–118.1ROR 90.8 · χ² 4,725 / p <1e-300 | 81.3 EB05 65.3 · IC025 +5.2 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=30 | not reported in cached trials |
| Fractional exhaled nitric oxide increased | 11 | 71.4 38.8–131.6ROR 71.5 · χ² 650 / p 9e-144 | 60.3 EB05 35.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=5 | not reported in cached trials |
| Bacterial disease carrier | 38 | 58.0 41.8–80.4ROR 58.1 · χ² 1,962 / p <1e-300 | 53.6 EB05 40.7 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | serious n=38 · ♀ 100% (drug 70%) | not reported in cached trials |
| Bronchial wall thickening | 36 | 55.0 39.4–76.9ROR 55.1 · χ² 1,762 / p <1e-300 | 51.0 EB05 38.5 · IC025 +4.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=36 · ♀ 100% (drug 70%) | not reported in cached trials |
| Brain malformation | 16 | 49.2 29.8–81.2ROR 49.2 · χ² 676 / p 3e-149 | 44.7 EB05 29.2 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Bronchial secretion retention | 46 | 39.8 29.6–53.4ROR 39.9 · χ² 1,637 / p <1e-300 | 37.8 EB05 29.5 · IC025 +4.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=42 · ♀ 93% (drug 70%) | not reported in cached trials |
| Hypereosinophilic syndrome | 17 | 34.8 21.5–56.4ROR 34.8 · χ² 507 / p 1e-112 | 32.6 EB05 21.5 · IC025 +3.3 3/3 methods agree | Likely indication confounding term in indications | serious n=13 | not reported in cached trials |
| Eosinophil count increased | 246 | 32.1 28.3–36.5ROR 32.5 · χ² 7,173 / p <1e-300 | 31.1 EB05 28.0 · IC025 +4.7 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 18.1 | not reported in cached trials |
| Asthma | 3,003 | 29.0 28.0–30.0ROR 34.0 · χ² 79,371 / p <1e-300 | 28.2 EB05 27.4 · IC025 +4.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 24.2 | NCT01928771: 24/394 (6.1%) on Benralizumab; 32/407 (7.9%) control (serious AE) |
| Bronchial obstruction | 37 | 28.4 20.5–39.4ROR 28.5 · χ² 927 / p 7e-204 | 27.4 EB05 20.7 · IC025 +3.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=37 | not reported in cached trials |
| Asthmatic crisis | 85 | 25.1 20.2–31.1ROR 25.2 · χ² 1,895 / p <1e-300 | 24.4 EB05 20.3 · IC025 +4.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=85 · ♀ 91% (drug 70%) | not reported in cached trials |
| Sars-cov-2 test negative | 15 | 23.6 14.2–39.4ROR 23.6 · χ² 296 / p 1e-66 | 22.5 EB05 14.3 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious n=11 | not reported in cached trials |
| Bronchopulmonary aspergillosis allergic | 20 | 23.5 15.1–36.6ROR 23.5 · χ² 399 / p 4e-89 | 22.5 EB05 15.3 · IC025 +3.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=19 · 100% clinician | not reported in cached trials |
| Asthma-chronic obstructive pulmonary disease overlap syndrome | 11 | 22.7 12.5–41.3ROR 22.7 · χ² 203 / p 3e-46 | 21.3 EB05 12.2 · IC025 +2.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=8 | not reported in cached trials |
| Nasal polyps | 97 | 21.6 17.7–26.4ROR 21.7 · χ² 1,848 / p <1e-300 | 21.1 EB05 17.8 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=49 | NCT01928771: 2/403 (0.5%) on Benralizumab; 1/407 (0.2%) control (serious AE) |
| Eosinophil count decreased | 46 | 21.3 15.9–28.5ROR 21.3 · χ² 850 / p 3e-187 | 20.7 EB05 16.1 · IC025 +3.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=17 | not reported in cached trials |
| Blood immunoglobulin e increased | 42 | 18.5 13.6–25.1ROR 18.5 · χ² 665 / p 6e-147 | 18.0 EB05 13.8 · IC025 +3.4 3/3 methods agree | Lab value / disease marker | serious n=28 | not reported in cached trials |
| Congenital central nervous system anomaly | 16 | 15.9 9.7–26.0ROR 15.9 · χ² 205 / p 8e-47 | 14.9 EB05 9.1 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Symptom recurrence | 81 | 14.7 11.8–18.4ROR 14.8 · χ² 1,010 / p 6e-222 | 14.5 EB05 12.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Cerebral ventricle dilatation | 16 | 14.7 9.0–24.1ROR 14.8 · χ² 189 / p 3e-43 | 13.7 EB05 8.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Full blood count abnormal | 140 | 14.2 12.0–16.7ROR 14.3 · χ² 1,679 / p <1e-300 | 13.9 EB05 12.1 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious PRR 16.6 | not reported in cached trials |
| Wheezing | 748 | 13.5 12.6–14.5ROR 14.0 · χ² 8,549 / p <1e-300 | 13.3 EB05 12.5 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 10.9 | not reported in cached trials |
| Obstructive airways disorder | 140 | 13.4 11.3–15.8ROR 13.5 · χ² 1,571 / p <1e-300 | 13.2 EB05 11.4 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 12.2 | not reported in cached trials |
| Forced expiratory volume decreased | 32 | 12.0 8.5–17.0ROR 12.0 · χ² 309 / p 2e-69 | 11.4 EB05 8.2 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious n=23 | not reported in cached trials |
| Increased bronchial secretion | 28 | 11.6 8.0–16.9ROR 11.6 · χ² 258 / p 2e-58 | 10.9 EB05 7.6 · IC025 +2.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=28 · ♀ 100% (drug 70%) | not reported in cached trials |
| Post-acute covid-19 syndrome | 13 | 11.2 6.5–19.3ROR 11.2 · χ² 110 / p 6e-26 | 9.5 EB05 5.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious n=10 | not reported in cached trials |
| Device leakage | 426 | 10.7 9.7–11.8ROR 10.9 · χ² 3,708 / p <1e-300 | 10.6 EB05 9.7 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious n=53 · 85% consumer | not reported in cached trials |
| Obstructive sleep apnoea syndrome | 14 | 10.7 6.3–18.1ROR 10.7 · χ² 112 / p 2e-26 | 9.1 EB05 5.3 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Pulmonary function test decreased | 44 | 10.6 7.9–14.3ROR 10.7 · χ² 371 / p 6e-83 | 10.1 EB05 7.7 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=35 | not reported in cached trials |
| Spinal cord compression | 39 | 10.6 7.7–14.5ROR 10.6 · χ² 327 / p 3e-73 | 10.0 EB05 7.5 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 95% (drug 70%) | not reported in cached trials |
| Pneumonia pseudomonal | 15 | 10.5 6.3–17.5ROR 10.5 · χ² 118 / p 7e-28 | 9.0 EB05 5.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Pulmonary function test abnormal | 15 | 10.2 6.1–17.0ROR 10.2 · χ² 114 / p 5e-27 | 8.7 EB05 5.3 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious n=12 | not reported in cached trials |
| Injection site indentation | 19 | 9.9 6.3–15.6ROR 9.9 · χ² 142 / p 5e-33 | 8.7 EB05 5.6 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | – | not reported in cached trials |
| Sputum discoloured | 88 | 9.9 8.0–12.2ROR 9.9 · χ² 689 / p 4e-152 | 9.6 EB05 8.0 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.0 | not reported in cached trials |
| Incorrect dose administered by device | 232 | 9.7 8.5–11.0ROR 9.8 · χ² 1,789 / p <1e-300 | 9.5 EB05 8.5 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious n=13 · 80% consumer | not reported in cached trials |
| Oligohydramnios | 30 | 9.5 6.6–13.6ROR 9.5 · χ² 218 / p 1e-49 | 8.7 EB05 6.3 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=30 · ♀ 100% (drug 70%) · 100% clinician | not reported in cached trials |
| Pneumocystis jirovecii infection | 10 | 9.2 4.9–17.2ROR 9.2 · χ² 65 / p 4e-16 | 7.2 EB05 3.9 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=10 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Benralizumab as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (2 of 40 signal terms matched).
- NCT01928771 — Efficacy and Safety Study of Benralizumab Added to High-dose Inhaled Corticosteroid Plus LABA in Patients With (N=2681, PHASE3; 110 AE terms posted; arms: Benralizumab 30 mg q.4 Weeks; Benralizumab 30 mg q.8 Weeks; Placebo)
- NCT01914757 — Efficacy and Safety Study of Benralizumab in Adults and Adolescents Inadequately Controlled on Inhaled Cortico (N=2508, PHASE3; 115 AE terms posted; arms: Benralizumab 30 mg q.4 Weeks; Benralizumab 30 mg q.8 Weeks; Placebo)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Asthma | 3,003 | 29.0 28.0–30.0ROR 34.0 · χ² 79,371 / p <1e-300 | 28.2 EB05 27.4 · IC025 +4.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 24.2 | NCT01928771: 24/394 (6.1%) on Benralizumab; 32/407 (7.9%) control (serious AE) |
| Dyspnoea (shortness of breath) | 1,999 | 3.7 3.6–3.9ROR 4.0 · χ² 4,098 / p <1e-300 | 3.7 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.1 | not reported in cached trials |
| Death | 1,646 | 2.0 1.9–2.1ROR 2.1 · χ² 877 / p 5e-193 | 2.0 EB05 1.9 · IC025 +0.9 | Outcome field, not a reaction | serious PRR 1.8 | NCT01928771: 1/407 (0.2%) control (serious AE) |
| Drug ineffective (drug did not work) | 1,519 | 1.2 1.2–1.3ROR 1.2 · χ² 62 / p 2e-15 | 1.2 EB05 1.2 · IC025 +0.2 | Reporting / coding artifact | serious PRR 2.2 | not reported in cached trials |
| Pneumonia (lung infection) | 1,083 | 3.5 3.3–3.8ROR 3.7 · χ² 1,996 / p <1e-300 | 3.5 EB05 3.4 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.2 · 72% consumer | NCT01928771: 1/403 (0.2%) on Benralizumab (serious AE) |
| Cough | 1,053 | 4.0 3.8–4.2ROR 4.1 · χ² 2,368 / p <1e-300 | 4.0 EB05 3.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | NCT01928771: 13/394 (3.3%) on Benralizumab; 11/407 (2.7%) control |
| Product dose omission issue | 1,003 | 3.7 3.5–4.0ROR 3.9 · χ² 2,015 / p <1e-300 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 6.0 · 81% consumer | not reported in cached trials |
| Headache | 934 | 1.6 1.5–1.7ROR 1.6 · χ² 200 / p 9e-46 | 1.6 EB05 1.5 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.3 | NCT01928771: 37/394 (9.4%) on Benralizumab; 21/407 (5.2%) control |
| Wheezing | 748 | 13.5 12.6–14.5ROR 14.0 · χ² 8,549 / p <1e-300 | 13.3 EB05 12.5 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 10.9 | not reported in cached trials |
| Fatigue (tiredness) | 641 | 0.9 0.8–0.9ROR 0.9 · χ² 13 / p 2e-4 | 0.9 EB05 0.8 · IC025 -0.3 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 0.8 | not reported in cached trials |
| Malaise (feeling unwell) | 621 | 1.5 1.4–1.6ROR 1.5 · χ² 102 / p 4e-24 | 1.5 EB05 1.4 · IC025 +0.4 | Not in label — unassessed | serious PRR 1.5 | not reported in cached trials |
| Inappropriate schedule of product administration | 591 | 3.5 3.3–3.8ROR 3.6 · χ² 1,076 / p 3e-236 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Reporting / coding artifact | serious PRR 5.3 | not reported in cached trials |
| Arthralgia (joint pain) | 559 | 1.4 1.3–1.5ROR 1.4 · χ² 71 / p 2e-17 | 1.4 EB05 1.3 · IC025 +0.4 | Not in label — unassessed | serious PRR 1.0 | NCT01928771: 18/394 (4.6%) on Benralizumab; 12/407 (2.9%) control |
| Pyrexia (fever) | 543 | 1.7 1.5–1.8ROR 1.7 · χ² 142 / p 5e-33 | 1.7 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.3 | NCT01928771: 12/394 (3.0%) on Benralizumab; 8/407 (2.0%) control |
| Rash | 516 | 1.3 1.2–1.4ROR 1.3 · χ² 27 / p 1e-7 | 1.3 EB05 1.2 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.1 | NCT01928771: 1/394 (0.3%) on Benralizumab (serious AE) |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Nasal polyps — n=97, PRR 21.6 (also seen in trial arm)
- Symptom recurrence — n=81, PRR 14.7
- Wheezing — n=748, PRR 13.5
- Obstructive airways disorder — n=140, PRR 13.4
- Pulmonary function test decreased — n=44, PRR 10.6
- Spinal cord compression — n=39, PRR 10.6
- Sputum discoloured — n=88, PRR 9.9
- Oligohydramnios — n=30, PRR 9.5
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Benralizumab?
In FDA FAERS, the most frequently co-reported reaction terms for Benralizumab are asthma, dyspnoea, pneumonia, cough, headache, wheezing. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Benralizumab have an FDA boxed warning?
No. The FDA label retrieved for Benralizumab has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Benralizumab causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID da6aca1a-19ed-44a4-abb7-696c7d58b784, effective 20260513; matched on
openfda.generic_name.exact:"BENRALIZUMAB") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,030 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath - ClinicalTrials.gov API v2 (query
BENRALIZUMAB, results-bearing studies sorted by enrollment)
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.