Reported Reactions

Drugs › Hydrolytic lysosomal glycosaminoglycan-specific enzyme

Brand name · Elosulfase alfa

Vimizim: adverse event reports filed with FDA

5,369 reports list it as a suspect or interacting product, 2014–2026. Class: Hydrolytic lysosomal glycosaminoglycan-specific enzyme.

5,369
reports as suspect product
0% of all reports · about 441 a year
430
reports, 12 months to June 2026
457 in the 12 months before
40.4%
marked serious by the reporter
63.8% across the class
2.4%
record death among outcomes, as reported
130 reports · not verified by FDA

5,369 adverse event reports received by FDA list the brand name Vimizim (elosulfase alfa) as a suspect or interacting product, from May 2014 to June 2026. A further 2 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 430 reports listed it, close to the 457 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 441 reports a year and 0% of the 20,646,523 reports in the database, and 31.2% of the reports for the hydrolytic lysosomal glycosaminoglycan-specific enzyme class. How many people take it is not in the data, so a count is not a rate of occurrence.

The MedDRA terms listed most often are pyrexia (13.5%), cough (6.4%) and vomiting (6.1%). A report can list several reactions, so shares add to more than 100%; 493 different terms appear across these reports. Pyrexia is recorded in 13.5% of these reports, about the same share as in the median hydrolytic lysosomal glycosaminoglycan-specific enzyme drug (12.7%).

40.4% of the reports are marked serious by the reporter (63.8% across the class); 2.4% record death among the outcomes and 21.1% record hospitalisation, as reported. 81.4% of the reports came from consumers, and the largest patient age group is 2 to 11 (16.9%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

02855Jul 2021: 34Aug 2021: 55Sep 2021: 38Oct 2021: 38Nov 2021: 50Dec 2021: 462022Jan 2022: 49Feb 2022: 36Mar 2022: 43Apr 2022: 24May 2022: 39Jun 2022: 41Jul 2022: 34Aug 2022: 52Sep 2022: 31Oct 2022: 36Nov 2022: 41Dec 2022: 382023Jan 2023: 40Feb 2023: 45Mar 2023: 33Apr 2023: 34May 2023: 39Jun 2023: 43Jul 2023: 40Aug 2023: 45Sep 2023: 31Oct 2023: 40Nov 2023: 35Dec 2023: 382024Jan 2024: 41Feb 2024: 39Mar 2024: 42Apr 2024: 27May 2024: 36Jun 2024: 26Jul 2024: 36Aug 2024: 31Sep 2024: 38Oct 2024: 38Nov 2024: 40Dec 2024: 312025Jan 2025: 52Feb 2025: 34Mar 2025: 50Apr 2025: 38May 2025: 36Jun 2025: 33Jul 2025: 47Aug 2025: 27Sep 2025: 36Oct 2025: 41Nov 2025: 20Dec 2025: 452026Jan 2026: 43Feb 2026: 32Mar 2026: 34Apr 2026: 33May 2026: 34Jun 2026: 38

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

02635262014: 15120142015: 4352016: 52620162017: 4452018: 44020182019: 4662020: 40620202021: 4752022: 46420222023: 4632024: 42520242025: 4592026: 2142026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Vimizim reports recording the termmedian drug in hydrolytic lysosomal glycosaminoglycan-specific enzyme

  1. Pyrexiafever13.5%726
  2. Coughcough6.4%344
  3. Vomitingbeing sick6.1%328
  4. Malaisegeneral feeling of being unwell5.3%286
  5. Headachehead pain4.8%258
  6. Dyspnoeashortness of breath4.3%231
  7. Painpain, site not specified4.3%230
  8. Nauseafeeling sick4.2%226
  9. Nasopharyngitisa cold3.6%193
  10. Fatiguetiredness3.6%191
  11. Pneumonialung infection3.1%166
  12. Product dose omissiona dose was missed2.9%154
  13. Pain in extremitypain in an arm or leg2.6%140
  14. Arthralgiajoint pain2.5%136
  15. Oropharyngeal painsore throat2.5%134
  16. Nasal congestiona blocked nose2.4%129
  17. Influenzaflu2.3%124
  18. Urticariahives2.2%116
  19. Rashskin rash1.9%101
  20. Abdominal pain upperupper stomach pain1.8%97
  21. Spinal cord compression1.8%96
  22. Heart rate increaseda fast heart rate reading1.8%94
  23. Knee deformity1.7%92
  24. Covid-19COVID-19 infection1.7%91
  25. Diarrhoealoose or frequent stools1.7%91
  26. Gait disturbancedifficulty walking1.7%89
  27. Pruritusitching1.6%87
  28. Tachycardiafast heart rate1.6%87
  29. Ear infectionan ear infection1.6%85

Top 30 of 493 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 6 drugs in the hydrolytic lysosomal glycosaminoglycan-specific enzyme class; it describes the reports, not the patients. 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."

Outcomes recorded

Death2.4%130
Life-threatening1.4%75
Hospitalisation (initial or prolonged)21.1%1,134
Disability1%53
Congenital anomaly0.2%13
Other serious19.9%1,069
Not serious59.6%3,200

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 17,202 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 20.7%37
2 to 1116.9%907
12 to 1710.3%555
18 to 4414.2%760
45 to 642.1%111
65 to 740.2%10
75 and over0%2
Age not given55.6%2,987

Patient sex

Female38.7%2,076
Male30.1%1,614
Not given31.3%1,679

Who reported

Physician4.5%239
Pharmacist0.5%27
Other health professional13.5%726
Lawyer0%0
Consumer or non-health professional81.4%4,373
Not given0.1%4

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 70.9% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Mucopolysaccharidosis iv3,99874.5%
Mucopolysaccharidosis811.5%
Mucopolysaccharidosis vi60.1%
Fabry's disease30.1%
Allergy test20%

The indication field is filled in by the reporter and is often blank; shares are of all 5,369 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Vimizim reports
Epinephrine56110.4%
Diphenhydramine5039.4%
Acetaminophen4989.3%
Heparin4127.7%
Lidocaine2935.5%
Ibuprofen2033.8%
Benadryl1893.5%
Tylenol1853.4%
Loratadine1763.3%
Diphenhydramine hydrochloride1753.3%

Other products listed in reports where Vimizim is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureVimizimHydrolytic lysosomal glycosaminoglycan-specific enzymeAll reports
Reports as suspect product5,36917,20220,646,523
Share of that pool—31.2%0%
Reports, latest 12 months430—1,332,454
Marked serious40.4%63.8%57.4%
Death recorded among outcomes, per 1,000 reports2410691
Hospitalisation recorded, per 1,000 reports211355213
Consumer-filed share81.4%64.7%45.8%
Top term, share of reportsPyrexia 13.5%median 12.7%1.6%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. 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."

Other drugs in the hydrolytic lysosomal glycosaminoglycan-specific enzyme class

DrugName typeReportsLatest 12 monthsMarked serious
Naglazymebrand3,82720165.9%
Aldurazymebrand3,22812870.6%
Idursulfasegeneric2,17013396.2%
Elaprasebrand1,7855178.8%
Laronidasegeneric82311162.5%

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." A brand and its generic are separate rows because reporters name them separately.

Questions about Vimizim reports

How many adverse event reports has FDA received for Vimizim?

5,369 reports list Vimizim as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 430 of them arrived in the latest 12 months. Another 2 list it only as a concomitant medication.

What reactions are recorded in Vimizim reports?

pyrexia (13.5%), cough (6.4%), vomiting (6.1%), malaise (5.3%) and headache (4.8%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Vimizim was responsible.

How serious are the reports?

40.4% are marked serious by the reporter. Among the outcomes recorded, 2.4% of reports include death and 21.1% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

consumer or non-health professional (81.4%), other health professional (13.5%) and physician (4.5%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Vimizim rising?

430 reports in the 12 months to June 2026, close to the 457 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Vimizim was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Vimizim?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. 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 report counts here when it lists Vimizim as a suspect or interacting product; reports listing it only as a concomitant medication (2) are excluded. 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.