Elosulfase Alfa side effects: what 5,367 FDA adverse event reports show
Drug class
Hydrolytic Lysosomal Glycosaminoglycan-specific Enzyme
Brand names
Vimizim
Who reports
5,367 reports · 41% serious · 131 with death outcome · 56% female
Used for
VIMIZIM (elosulfase alfa) is indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). VIMIZIM is a hydrolytic lysosomal glycosaminoglycan (GAG)-specific enzyme indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). ( 1 )
What it is
Elosulfase alfa is a purified human enzyme produced by recombinant DNA technology in a Chinese hamster ovary cell line. Human N-acetylgalactosamine-6-sulfatase (EC 3.1.6.4) is a hydrolytic lys.
Boxed warning
HYPERSENSITIVITY REACTIONS INCLUDING ANAPHYLAXIS and RISK OF ACUTE RESPIRATORY COMPLICATIONS Patients treated with enzyme replacement therapies have experienced life-threatening hypersensitivity reactions, including anaphylaxis. Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- 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. 67 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Knee operation | 74 | 29.9 23.8–37.6ROR 30.3 · χ² 2,025 / p <1e-300 | 29.5 EB05 24.3 · IC025 +4.3 3/3 methods agree | Reporting / coding artifact | serious PRR 43.8 · 85% consumer | no trial data cached |
| Poor venous access | 60 | 22.8 17.7–29.3ROR 23.0 · χ² 1,221 / p 7e-268 | 22.5 EB05 18.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=21 · 72% consumer | no trial data cached |
| Ear infection | 86 | 12.7 10.3–15.6ROR 12.9 · χ² 911 / p 2e-200 | 12.5 EB05 10.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 · 84% consumer | no trial data cached |
| Oxygen saturation decreased | 153 | 10.7 9.2–12.5ROR 11.0 · χ² 1,337 / p 4e-293 | 10.6 EB05 9.2 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious PRR 15.4 · 75% consumer | no trial data cached |
| Body temperature increased | 55 | 10.5 8.1–13.7ROR 10.6 · χ² 462 / p 8e-103 | 10.1 EB05 8.0 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious PRR 5.7 · 82% consumer | no trial data cached |
| Gastroenteritis viral | 48 | 10.4 7.8–13.7ROR 10.4 · χ² 396 / p 2e-88 | 9.9 EB05 7.7 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 1.7 · 90% consumer | no trial data cached |
| Cyanosis (blue skin from low oxygen) | 40 | 9.9 7.3–13.5ROR 10.0 · χ² 311 / p 6e-70 | 9.4 EB05 7.1 · IC025 +2.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 14.5 · 75% consumer | no trial data cached |
| Respiratory distress | 65 | 9.2 7.2–11.7ROR 9.3 · χ² 466 / p 1e-103 | 8.9 EB05 7.1 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 12.8 · 82% consumer | no trial data cached |
| Product dose omission | 155 | 9.1 7.8–10.7ROR 9.4 · χ² 1,117 / p 4e-245 | 9.0 EB05 7.8 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 15.7 · 88% consumer | no trial data cached |
| Pharyngitis streptococcal | 25 | 9.0 6.1–13.3ROR 9.1 · χ² 170 / p 4e-39 | 8.2 EB05 5.7 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | 96% consumer | no trial data cached |
| Spinal operation | 27 | 8.7 6.0–12.7ROR 8.7 · χ² 176 / p 2e-40 | 7.9 EB05 5.6 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 13.5 | no trial data cached |
| Nasal congestion (stuffy nose) | 129 | 8.6 7.3–10.2ROR 8.8 · χ² 860 / p 2e-189 | 8.4 EB05 7.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 · 84% consumer | no trial data cached |
| Pyrexia (fever) | 726 | 8.2 7.7–8.8ROR 9.3 · χ² 4,641 / p <1e-300 | 8.1 EB05 7.7 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.8 · 85% consumer | no trial data cached |
| Joint dislocation | 20 | 7.4 4.8–11.5ROR 7.4 · χ² 105 / p 8e-25 | 6.5 EB05 4.4 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 10.1 | no trial data cached |
| Secretion discharge | 23 | 7.3 4.8–10.9ROR 7.3 · χ² 118 / p 9e-28 | 6.5 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 · 74% consumer | no trial data cached |
| Ear pain | 35 | 7.0 5.0–9.8ROR 7.1 · χ² 175 / p 3e-40 | 6.5 EB05 4.9 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.4 · 77% consumer | no trial data cached |
| Sleep apnoea syndrome | 33 | 6.7 4.8–9.5ROR 6.8 · χ² 155 / p 6e-36 | 6.2 EB05 4.6 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 9.0 | no trial data cached |
| Pallor | 46 | 6.6 4.9–8.8ROR 6.6 · χ² 212 / p 2e-48 | 6.2 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · 72% consumer | no trial data cached |
| Bronchospasm (airway tightening) | 24 | 6.5 4.4–9.8ROR 6.6 · χ² 107 / p 2e-25 | 5.9 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 10.3 · 71% consumer | no trial data cached |
| Device related infection | 25 | 6.3 4.3–9.4ROR 6.3 · χ² 107 / p 3e-25 | 5.7 EB05 4.1 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious PRR 7.7 · 80% consumer | no trial data cached |
| Spinal disorder | 15 | 6.2 3.7–10.2ROR 6.2 · χ² 60 / p 5e-15 | 5.3 EB05 3.4 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.2 | no trial data cached |
| Respiratory disorder | 45 | 5.9 4.4–7.8ROR 5.9 · χ² 176 / p 2e-40 | 5.5 EB05 4.3 · IC025 +2.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.2 · 80% consumer | no trial data cached |
| Sars-cov-2 test positive | 20 | 5.8 3.8–9.1ROR 5.9 · χ² 75 / p 2e-18 | 5.2 EB05 3.5 · IC025 +1.6 3/3 methods agree | Lab value / disease marker | 90% consumer | no trial data cached |
| Oropharyngeal pain (sore throat) | 134 | 5.6 4.8–6.7ROR 5.8 · χ² 509 / p 4e-113 | 5.5 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 · 87% consumer | no trial data cached |
| Upper respiratory tract infection (cold/sinus infection) | 64 | 5.4 4.2–6.9ROR 5.5 · χ² 226 / p 2e-51 | 5.2 EB05 4.2 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 2.7 · 75% consumer | no trial data cached |
| Deafness | 36 | 5.4 3.9–7.4ROR 5.4 · χ² 123 / p 6e-29 | 5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 · 83% consumer | no trial data cached |
| Infusion site pain | 17 | 5.2 3.2–8.4ROR 5.2 · χ² 53 / p 1e-13 | 4.6 EB05 3.0 · IC025 +1.4 3/3 methods agree | Labeled (related wording) related wording | serious n=2 | no trial data cached |
| Foot deformity | 14 | 4.9 2.9–8.3ROR 4.9 · χ² 40 / p 1e-10 | 4.3 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 | no trial data cached |
| Cough | 344 | 4.8 4.3–5.3ROR 5.1 · χ² 1,043 / p 5e-229 | 4.8 EB05 4.4 · IC025 +2.1 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.8 · 82% consumer | no trial data cached |
| Device occlusion | 17 | 4.8 3.0–7.7ROR 4.8 · χ² 47 / p 4e-12 | 4.3 EB05 2.8 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious n=6 | no trial data cached |
| Infusion related reaction (reaction during infusion) | 80 | 4.7 3.8–5.9ROR 4.8 · χ² 232 / p 1e-52 | 4.6 EB05 3.8 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.0 · 70% consumer | no trial data cached |
| Respiratory tract congestion | 19 | 4.7 3.0–7.3ROR 4.7 · χ² 51 / p 5e-13 | 4.2 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.4 | no trial data cached |
| Respiratory tract infection | 31 | 4.7 3.3–6.6ROR 4.7 · χ² 85 / p 1e-20 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 · 90% consumer | no trial data cached |
| Viral infection | 39 | 4.6 3.3–6.3ROR 4.6 · χ² 106 / p 5e-25 | 4.4 EB05 3.3 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 2.1 · 87% consumer | no trial data cached |
| Influenza | 125 | 4.4 3.7–5.2ROR 4.4 · χ² 322 / p 3e-72 | 4.3 EB05 3.7 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.8 · 88% consumer | no trial data cached |
| Spinal pain | 13 | 4.3 2.5–7.5ROR 4.3 · χ² 30 / p 2e-8 | 3.8 EB05 2.4 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.8 | no trial data cached |
| Tachypnoea | 15 | 4.3 2.6–7.2ROR 4.3 · χ² 35 / p 2e-9 | 3.9 EB05 2.5 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Rhinorrhoea (runny nose) | 70 | 4.2 3.4–5.3ROR 4.3 · χ² 170 / p 3e-39 | 4.1 EB05 3.4 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · 81% consumer | no trial data cached |
| Nasopharyngitis (common cold) | 193 | 4.1 3.5–4.7ROR 4.2 · χ² 448 / p 8e-100 | 4.0 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 · 84% consumer | no trial data cached |
| Atelectasis | 10 | 4.0 2.2–7.5ROR 4.0 · χ² 20 / p 4e-6 | 3.5 EB05 2.1 · IC025 +0.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Pyrexia (fever) | 726 | 8.2 7.7–8.8ROR 9.3 · χ² 4,641 / p <1e-300 | 8.1 EB05 7.7 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.8 · 85% consumer | no trial data cached |
| Cough | 344 | 4.8 4.3–5.3ROR 5.1 · χ² 1,043 / p 5e-229 | 4.8 EB05 4.4 · IC025 +2.1 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.8 · 82% consumer | no trial data cached |
| Vomiting | 329 | 2.7 2.5–3.0ROR 2.8 · χ² 369 / p 2e-82 | 2.7 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 2.2 · 80% consumer | no trial data cached |
| Malaise (feeling unwell) | 286 | 2.5 2.3–2.8ROR 2.6 · χ² 270 / p 5e-61 | 2.5 EB05 2.3 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 1.9 · 90% consumer | no trial data cached |
| Nasopharyngitis (common cold) | 193 | 4.1 3.5–4.7ROR 4.2 · χ² 448 / p 8e-100 | 4.0 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 · 84% consumer | no trial data cached |
| Product dose omission | 155 | 9.1 7.8–10.7ROR 9.4 · χ² 1,117 / p 4e-245 | 9.0 EB05 7.8 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 15.7 · 88% consumer | no trial data cached |
| Oxygen saturation decreased | 153 | 10.7 9.2–12.5ROR 11.0 · χ² 1,337 / p 4e-293 | 10.6 EB05 9.2 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious PRR 15.4 · 75% consumer | no trial data cached |
| Pain in extremity | 140 | 1.8 1.6–2.2ROR 1.9 · χ² 54 / p 8e-14 | 1.8 EB05 1.6 · IC025 +0.6 | Not in label — unassessed | serious PRR 2.5 · 81% consumer | no trial data cached |
| Oropharyngeal pain (sore throat) | 134 | 5.6 4.8–6.7ROR 5.8 · χ² 509 / p 4e-113 | 5.5 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 · 87% consumer | no trial data cached |
| Nasal congestion (stuffy nose) | 129 | 8.6 7.3–10.2ROR 8.8 · χ² 860 / p 2e-189 | 8.4 EB05 7.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 · 84% consumer | no trial data cached |
| Influenza | 125 | 4.4 3.7–5.2ROR 4.4 · χ² 322 / p 3e-72 | 4.3 EB05 3.7 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.8 · 88% consumer | no trial data cached |
| Urticaria (hives) | 119 | 2.8 2.3–3.3ROR 2.8 · χ² 136 / p 1e-31 | 2.8 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 1.9 | no trial data cached |
| Abdominal pain upper | 98 | 1.9 1.5–2.3ROR 1.9 · χ² 38 / p 3e-10 | 1.9 EB05 1.6 · IC025 +0.6 | Labeled (related wording) related wording | serious PRR 1.2 · 76% consumer | no trial data cached |
| Heart rate increased | 95 | 3.7 3.1–4.6ROR 3.8 · χ² 189 / p 3e-43 | 3.7 EB05 3.1 · IC025 +1.5 3/3 methods agree | Lab value / disease marker | serious PRR 3.6 | no trial data cached |
| Covid-19 | 91 | 2.0 1.6–2.5ROR 2.0 · χ² 45 / p 9e-12 | 2.0 EB05 1.7 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.2 · 81% 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.
- Poor venous access — n=60, PRR 22.8
- Ear infection — n=86, PRR 12.7
- Gastroenteritis viral — n=48, PRR 10.4
- Respiratory distress — n=65, PRR 9.2
- Pharyngitis streptococcal — n=25, PRR 9.0
- Nasal congestion — n=129, PRR 8.6
- Joint dislocation — n=20, PRR 7.4
- Secretion discharge — n=23, PRR 7.3
- Pallor — n=46, PRR 6.6
- Bronchospasm — n=24, PRR 6.5
✓ 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 Elosulfase Alfa?
In FDA FAERS, the most frequently co-reported reaction terms for Elosulfase Alfa are pyrexia, cough, vomiting, malaise, nasopharyngitis, oxygen saturation decreased. 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 Elosulfase Alfa have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: HYPERSENSITIVITY REACTIONS INCLUDING ANAPHYLAXIS and RISK OF ACUTE RESPIRATORY COMPLICATIONS Patients treated with enzyme replacement therapies have experienced life-threatening hypersensitivity reactions, including anaphylaxis. Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy.
Do FAERS signals prove that Elosulfase 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 0caa2565-12b2-0ad0-1f9a-273e81c3d4cc, effective 20251030; matched on
openfda.generic_name.exact:"ELOSULFASE 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, 107 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.