Reported Reactions

Drugs

Brand name · Emicizumab

Hemlibra: adverse event reports filed with FDA

10,620 reports list it as a suspect or interacting product, 2017–2026.

10,620
reports as suspect product
0.1% of all reports · about 1,138 a year
1,702
reports, 12 months to June 2026
3,717 in the 12 months before
32.9%
marked serious by the reporter
57.4% across all reports
3%
record death among outcomes, as reported
320 reports · not verified by FDA

Between March 2017 and June 2026, 10,620 adverse event reports received by FDA list the brand name Hemlibra (emicizumab) as a suspect or interacting product. Reports that mention it only as a concomitant medication (648) are left out of every figure here.

In the 12 months to June 2026, 1,702 reports listed it, down 54% from 3,717 in 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 1,138 reports a year and 0.1% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded haemorrhage (39.4%), no adverse event (6.6%) and off label use (5.8%). A report can list several reactions, so shares add to more than 100%; 598 different terms appear across these reports. Haemorrhage is recorded in 39.4% of these reports, against 0.5% of all reports in the database.

32.9% of the reports are marked serious by the reporter; 3% record death among the outcomes and 14.7% record hospitalisation, as reported. 70.9% of the reports came from consumers, and the largest patient age group is 18 to 44 (19.1%). 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

09141,828Jul 2021: 20Aug 2021: 26Sep 2021: 27Oct 2021: 33Nov 2021: 38Dec 2021: 442022Jan 2022: 409Feb 2022: 24Mar 2022: 47Apr 2022: 26May 2022: 28Jun 2022: 37Jul 2022: 40Aug 2022: 34Sep 2022: 50Oct 2022: 54Nov 2022: 44Dec 2022: 532023Jan 2023: 662Feb 2023: 47Mar 2023: 58Apr 2023: 107May 2023: 52Jun 2023: 45Jul 2023: 38Aug 2023: 50Sep 2023: 49Oct 2023: 41Nov 2023: 42Dec 2023: 1,5292024Jan 2024: 44Feb 2024: 37Mar 2024: 50Apr 2024: 43May 2024: 46Jun 2024: 105Jul 2024: 236Aug 2024: 211Sep 2024: 207Oct 2024: 1,828Nov 2024: 160Dec 2024: 2052025Jan 2025: 146Feb 2025: 129Mar 2025: 143Apr 2025: 161May 2025: 136Jun 2025: 155Jul 2025: 147Aug 2025: 134Sep 2025: 118Oct 2025: 136Nov 2025: 130Dec 2025: 1522026Jan 2026: 123Feb 2026: 128Mar 2026: 192Apr 2026: 137May 2026: 132Jun 2026: 173

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

01,5863,1722017: 120172018: 12720182019: 27420192020: 44120202021: 46720212022: 84620222023: 2,72020232024: 3,17220242025: 1,68720252026: 8852026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Hemlibra reports recording the termall reports in the database

  1. Haemorrhagebleeding39.4%4,189
  2. No adverse eventno adverse event was reported6.6%700
  3. Off label useused for a purpose or in a way not on the label5.8%617
  4. Falla fall5.5%586
  5. Arthralgiajoint pain4.2%441
  6. Epistaxisnosebleed3.5%375
  7. Contusiona bruise3.5%371
  8. Head injurya head injury2.9%309
  9. Painpain, site not specified2.8%300
  10. Muscle haemorrhage2.4%259
  11. Injurya physical injury1.8%194
  12. Weight increasedweight gain1.8%187
  13. Headachehead pain1.4%148
  14. Joint swellinga swollen joint1.4%144
  15. Injection site painpain where the injection was given1.3%142
  16. Drug ineffectivethe medicine did not work as expected1.3%138
  17. Haematomaa collection of blood under the skin or in tissue1.2%129
  18. Deaththe patient died; cause not stated by this term1.2%125
  19. Skin lacerationa cut in the skin1.1%120
  20. Swellingswelling1.1%119
  21. Gingival bleedingbleeding gums1.1%114
  22. Weight decreasedweight loss1%110
  23. Pain in extremitypain in an arm or leg1%103
  24. Pyrexiafever1%102
  25. Gastrointestinal haemorrhagebleeding in the stomach or bowel0.9%97

Top 30 of 598 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 share of all reports in the database; 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

Death3%320
Life-threatening0.6%67
Hospitalisation (initial or prolonged)14.7%1,560
Disability0.4%38
Congenital anomaly0%0
Other serious17.4%1,851
Not serious67.1%7,131

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 20,646,523 reports. 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 22.3%244
2 to 1111.4%1,211
12 to 177%742
18 to 4419.1%2,029
45 to 647.2%762
65 to 742.2%236
75 and over2.6%274
Age not given48.2%5,122

Patient sex

Female3.3%351
Male86.4%9,177
Not given10.3%1,092

Who reported

Physician19%2,021
Pharmacist2.7%285
Other health professional7.2%766
Lawyer0%0
Consumer or non-health professional70.9%7,530
Not given0.2%18

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 79.7% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Factor viii deficiency7,39769.7%
Haemophilia a without inhibitors6406%
Haemophilia3923.7%
Acquired haemophilia3002.8%
Haemophilia a with anti factor viii1301.2%
Factor vii deficiency980.9%

The indication field is filled in by the reporter and is often blank; shares are of all 10,620 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Hemlibra reports
Advate4844.6%
Eloctate1921.8%
Kovaltry1081%
Adynovate980.9%
Sodium chloride630.6%
Prednisolone600.6%
Tylenol580.5%
Tranexamic acid530.5%
Recombinate380.4%
Rituximab370.3%

Other products listed in reports where Hemlibra 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

MeasureHemlibraAll reports
Reports as suspect product10,62020,646,523
Share of that pool—0.1%
Reports, latest 12 months1,7021,332,454
Marked serious32.9%57.4%
Death recorded among outcomes, per 1,000 reports3091
Hospitalisation recorded, per 1,000 reports147213
Consumer-filed share70.9%45.8%
Top term, share of reportsHaemorrhage 39.4%0.5%

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."

Questions about Hemlibra reports

How many adverse event reports has FDA received for Hemlibra?

10,620 reports list Hemlibra as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,702 of them arrived in the latest 12 months. Another 648 list it only as a concomitant medication.

What reactions are recorded in Hemlibra reports?

haemorrhage (39.4%), no adverse event (6.6%), off label use (5.8%), fall (5.5%) and haemarthrosis (5.5%). 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 Hemlibra was responsible.

How serious are the reports?

32.9% are marked serious by the reporter. Among the outcomes recorded, 3% of reports include death and 14.7% 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 (70.9%), physician (19%) and other health professional (7.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Hemlibra rising?

1,702 reports in the 12 months to June 2026, down 54% from 3,717 in 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 Hemlibra 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 Hemlibra?

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 Hemlibra as a suspect or interacting product; reports listing it only as a concomitant medication (648) 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.