Drug · FAERS side-effect profile with label screen
Efgartigimod Alfa side effects: what 3,880 FDA adverse event reports show
Drug class
FDA label (Established Pharmacologic Class) · compare the class
Brand names
Vyvgart
openFDA label
Who reports
3,880 reports · 92% serious · 372 with death outcome · 54% female
openFDA FAERS counts, all years, deduplication not applied
Used for
VYVGART is indicated for the treatment of adult patients with generalized myasthenia gravis (gMG). VYVGART is a neonatal Fc receptor blocker indicated for the treatment of adult patients with generalized myasthenia gravis (gMG). ( 1 )
FDA label, Indications and Usage
What it is
Efgartigimod alfa-fcab is a human immunoglobulin G1 (IgG1) -derived Fc fragment (fragment, crystallized) of the za allotype. The efgartigimod alfa-fcab Fc fragment is a homodimer consisting of.
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 adverse reaction 2Labeled (related wording) 1Reporting / coding artifact 9Lab value / disease marker 1Not in label — unassessed 27
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- 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. 136 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 |
|---|---|---|---|---|---|---|
| Eyelid ptosis | 114 | 61.3 51.1–73.5ROR 63.1 · χ² 6,624 / p <1e-300 | 60.0 EB05 51.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=105 · 83% consumer | no trial data cached |
| Therapy change | 50 | 28.2 21.4–37.1ROR 28.5 · χ² 1,277 / p 6e-280 | 27.8 EB05 21.9 · IC025 +4.0 3/3 methods agree | Reporting / coding artifact | serious n=49 | no trial data cached |
| Choking | 97 | 27.1 22.3–33.0ROR 27.8 · χ² 2,405 / p <1e-300 | 26.9 EB05 22.7 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 19.4 · 90% consumer | no trial data cached |
| Diplopia (double vision) | 123 | 25.7 21.6–30.6ROR 26.5 · χ² 2,886 / p <1e-300 | 25.5 EB05 21.9 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 19.5 · 84% consumer | no trial data cached |
| Poor venous access | 35 | 18.4 13.2–25.6ROR 18.5 · χ² 556 / p 3e-123 | 18.1 EB05 13.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=32 · 74% consumer | no trial data cached |
| Therapeutic response shortened | 89 | 15.2 12.3–18.6ROR 15.5 · χ² 1,161 / p 1e-254 | 15.0 EB05 12.6 · IC025 +3.5 3/3 methods agree | Reporting / coding artifact | serious PRR 24.9 · 81% consumer | no trial data cached |
| Drug effect less than expected | 31 | 11.9 8.4–16.9ROR 12.0 · χ² 298 / p 4e-67 | 11.4 EB05 8.1 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious n=29 · 97% consumer | no trial data cached |
| Dysarthria (slurred speech) | 82 | 11.8 9.5–14.6ROR 12.0 · χ² 800 / p 3e-176 | 11.6 EB05 9.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 88% consumer | no trial data cached |
| Therapy non-responder | 85 | 10.3 8.4–12.7ROR 10.5 · χ² 707 / p 6e-156 | 10.1 EB05 8.4 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 9.9 · ♀ 77% (drug 54%) | no trial data cached |
| Dysphagia (difficulty swallowing) | 176 | 10.1 8.7–11.6ROR 10.5 · χ² 1,432 / p <1e-300 | 9.9 EB05 8.7 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · 79% consumer | no trial data cached |
| Diverticulitis | 48 | 9.4 7.1–12.5ROR 9.5 · χ² 352 / p 8e-79 | 9.0 EB05 6.9 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · 96% consumer | no trial data cached |
| Muscular weakness | 196 | 9.3 8.1–10.7ROR 9.8 · χ² 1,456 / p <1e-300 | 9.2 EB05 8.2 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 · 79% consumer | no trial data cached |
| Therapy cessation | 88 | 9.3 7.6–11.5ROR 9.5 · χ² 646 / p 8e-143 | 9.1 EB05 7.5 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 12.4 · 84% consumer | no trial data cached |
| Insurance issue | 24 | 8.7 5.9–13.0ROR 8.8 · χ² 157 / p 3e-36 | 7.9 EB05 5.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 · 88% consumer | no trial data cached |
| Sars-cov-2 test positive | 20 | 8.1 5.2–12.5ROR 8.1 · χ² 117 / p 1e-27 | 7.1 EB05 4.8 · IC025 +2.0 3/3 methods agree | Lab value / disease marker | serious n=20 · 90% consumer | no trial data cached |
| Spinal operation | 18 | 8.0 5.1–12.8ROR 8.1 · χ² 104 / p 1e-24 | 7.0 EB05 4.6 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 5.5 | no trial data cached |
| Therapeutic product effect decreased | 65 | 7.9 6.2–10.1ROR 8.0 · χ² 387 / p 2e-86 | 7.6 EB05 6.1 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 9.1 · 71% consumer | no trial data cached |
| Upper respiratory tract infection (cold/sinus infection) | 65 | 7.6 6.0–9.7ROR 7.7 · χ² 368 / p 3e-82 | 7.3 EB05 5.9 · IC025 +2.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.6 · 83% consumer | no trial data cached |
| Pulmonary mass | 20 | 7.3 4.7–11.3ROR 7.3 · χ² 102 / p 3e-24 | 6.4 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Nephrolithiasis (kidney stones) | 58 | 6.9 5.3–8.9ROR 6.9 · χ² 285 / p 3e-64 | 6.5 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 91% consumer | no trial data cached |
| Therapy interrupted | 86 | 6.7 5.5–8.3ROR 6.9 · χ² 416 / p 1e-92 | 6.5 EB05 5.4 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 9.2 · 73% consumer | no trial data cached |
| Urinary tract infection (bladder infection) | 211 | 6.7 5.9–7.7ROR 7.0 · χ² 1,027 / p 1e-225 | 6.6 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 · ♀ 78% (drug 54%) · 72% consumer | no trial data cached |
| Pharyngeal swelling | 11 | 6.2 3.4–11.2ROR 6.2 · χ² 43 / p 3e-11 | 5.1 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Hospitalisation | 175 | 6.2 5.4–7.2ROR 6.5 · χ² 765 / p 1e-168 | 6.1 EB05 5.4 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 4.0 · 74% consumer | no trial data cached |
| Respiratory tract infection | 29 | 6.0 4.2–8.7ROR 6.1 · χ² 117 / p 1e-27 | 5.5 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 · 79% consumer | no trial data cached |
| Salivary hypersecretion | 11 | 6.0 3.3–10.7ROR 6.0 · χ² 41 / p 1e-10 | 4.9 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| Loss of personal independence in daily activities | 52 | 5.9 4.5–7.7ROR 6.0 · χ² 208 / p 2e-47 | 5.6 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Autoimmune disorder | 10 | 5.7 3.0–10.5ROR 5.7 · χ² 34 / p 3e-9 | 4.6 EB05 2.7 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Back injury | 11 | 5.5 3.0–9.9ROR 5.5 · χ² 36 / p 1e-9 | 4.6 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Dyspnoea exertional | 38 | 5.5 4.0–7.5ROR 5.5 · χ² 135 / p 2e-31 | 5.1 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 · 74% consumer | no trial data cached |
| Covid-19 | 174 | 5.3 4.6–6.2ROR 5.5 · χ² 610 / p 4e-135 | 5.2 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 · 72% consumer | no trial data cached |
| Pulmonary congestion | 13 | 5.3 3.1–9.1ROR 5.3 · χ² 41 / p 7e-11 | 4.5 EB05 2.8 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Herpes zoster (shingles) | 56 | 5.3 4.1–6.8ROR 5.3 · χ² 189 / p 2e-43 | 5.0 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 · 75% consumer | no trial data cached |
| Aspiration | 10 | 5.0 2.7–9.3ROR 5.0 · χ² 28 / p 6e-8 | 4.1 EB05 2.4 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | no trial data cached |
| Bedridden | 12 | 4.9 2.8–8.7ROR 5.0 · χ² 34 / p 3e-9 | 4.2 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Speech disorder | 47 | 4.9 3.7–6.4ROR 4.9 · χ² 140 / p 1e-32 | 4.6 EB05 3.6 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 · 79% consumer | no trial data cached |
| Mitral valve incompetence | 10 | 4.8 2.6–8.9ROR 4.8 · χ² 26 / p 2e-7 | 4.0 EB05 2.4 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 | no trial data cached |
| Pneumonia aspiration | 22 | 4.8 3.1–7.2ROR 4.8 · χ² 62 / p 2e-15 | 4.4 EB05 3.0 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 | no trial data cached |
| Brain fog | 12 | 4.4 2.5–7.8ROR 4.5 · χ² 29 / p 4e-8 | 3.9 EB05 2.4 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Rib fracture | 16 | 4.2 2.6–6.9ROR 4.2 · χ² 36 / p 9e-10 | 3.8 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 2.9 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 396 | 2.8 2.5–3.0ROR 3.0 · χ² 458 / p 7e-102 | 2.7 EB05 2.5 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.1 · 84% consumer | no trial data cached |
| Dyspnoea (shortness of breath) | 298 | 2.8 2.6–3.2ROR 3.0 · χ² 365 / p 1e-81 | 2.8 EB05 2.6 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 · 84% consumer | no trial data cached |
| Asthenia (weakness) | 259 | 3.7 3.3–4.2ROR 3.9 · χ² 522 / p 6e-116 | 3.7 EB05 3.3 · IC025 +1.7 3/3 methods agree | Likely indication confounding term in indications | serious PRR 3.1 · 81% consumer | no trial data cached |
| Fall | 222 | 3.6 3.2–4.1ROR 3.8 · χ² 423 / p 3e-94 | 3.6 EB05 3.2 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 2.6 · 86% consumer | no trial data cached |
| Urinary tract infection (bladder infection) | 211 | 6.7 5.9–7.7ROR 7.0 · χ² 1,027 / p 1e-225 | 6.6 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 · ♀ 78% (drug 54%) · 72% consumer | no trial data cached |
| Muscular weakness | 196 | 9.3 8.1–10.7ROR 9.8 · χ² 1,456 / p <1e-300 | 9.2 EB05 8.2 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 · 79% consumer | no trial data cached |
| Dysphagia (difficulty swallowing) | 176 | 10.1 8.7–11.6ROR 10.5 · χ² 1,432 / p <1e-300 | 9.9 EB05 8.7 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · 79% consumer | no trial data cached |
| Hospitalisation | 175 | 6.2 5.4–7.2ROR 6.5 · χ² 765 / p 1e-168 | 6.1 EB05 5.4 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 4.0 · 74% consumer | no trial data cached |
| Covid-19 | 174 | 5.3 4.6–6.2ROR 5.5 · χ² 610 / p 4e-135 | 5.2 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 · 72% consumer | no trial data cached |
| Inappropriate schedule of product administration | 137 | 4.2 3.6–4.9ROR 4.3 · χ² 332 / p 2e-74 | 4.1 EB05 3.6 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 6.0 · 80% consumer | no trial data cached |
| Diplopia (double vision) | 123 | 25.7 21.6–30.6ROR 26.5 · χ² 2,886 / p <1e-300 | 25.5 EB05 21.9 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 19.5 · 84% consumer | no trial data cached |
| Eyelid ptosis | 114 | 61.3 51.1–73.5ROR 63.1 · χ² 6,624 / p <1e-300 | 60.0 EB05 51.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=105 · 83% consumer | no trial data cached |
| Choking | 97 | 27.1 22.3–33.0ROR 27.8 · χ² 2,405 / p <1e-300 | 26.9 EB05 22.7 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 19.4 · 90% consumer | no trial data cached |
| Nasopharyngitis (common cold) | 94 | 2.8 2.3–3.4ROR 2.8 · χ² 104 / p 1e-24 | 2.7 EB05 2.3 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 87% consumer | no trial data cached |
| Product dose omission issue | 91 | 1.7 1.4–2.1ROR 1.7 · χ² 28 / p 8e-8 | 1.7 EB05 1.4 · IC025 +0.4 | Reporting / coding artifact | serious PRR 3.8 · 82% consumer | no trial data cached |
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.
- Eyelid ptosis — n=114, PRR 61.3
- Choking — n=97, PRR 27.1
- Diplopia — n=123, PRR 25.7
- Poor venous access — n=35, PRR 18.4
- Dysarthria — n=82, PRR 11.8
- Dysphagia — n=176, PRR 10.1
- Diverticulitis — n=48, PRR 9.4
- Muscular weakness — n=196, PRR 9.3
- Insurance issue — n=24, PRR 8.7
- Pulmonary mass — n=20, PRR 7.3
✓ A hand-written Bradford Hill causality assessment exists for this drug: Erythropoiesis-stimulating agents (darbepoetin alfa) ↔ Mortality / cardiovascular risk.
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 Efgartigimod Alfa?
In FDA FAERS, the most frequently co-reported reaction terms for Efgartigimod Alfa are fatigue, dyspnoea, asthenia, fall, urinary tract infection, muscular weakness. 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 Efgartigimod Alfa have an FDA boxed warning?
No. The FDA label retrieved for Efgartigimod Alfa has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Efgartigimod Alfa 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 8aefc8e3-26d6-4ff6-aab9-a7542927e084, effective 20260513; matched on
openfda.generic_name.exact:"EFGARTIGIMOD ALFA") - 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, 176 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
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.