Reported Reactions

Drugs

Brand name · Blinatumomab

Blincyto: adverse event reports filed with FDA

6,449 reports list it as a suspect or interacting product, 2015–2026.

6,449
reports as suspect product
0% of all reports · about 561 a year
524
reports, 12 months to June 2026
662 in the 12 months before
69.9%
marked serious by the reporter
57.4% across all reports
13%
record death among outcomes, as reported
836 reports · not verified by FDA

Between January 2015 and June 2026, 6,449 adverse event reports received by FDA list the brand name Blincyto (blinatumomab) as a suspect or interacting product. Reports that mention it only as a concomitant medication (117) are left out of every figure here.

In the 12 months to June 2026, 524 reports listed it, down 21% from 662 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 561 reports a year and 0% 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.

The MedDRA terms listed most often are pyrexia (13%), cytokine release syndrome (9.2%) and acute lymphocytic leukaemia recurrent (7.7%). A report can list several reactions, so shares add to more than 100%; 687 different terms appear across these reports. Pyrexia is recorded in 13% of these reports, against 1.6% of all reports in the database.

69.9% of the reports are marked serious by the reporter; 13% record death among the outcomes and 23% record hospitalisation, as reported. 47% of the reports came from physicians, and the largest patient age group is 18 to 44 (18.4%). 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

04487Jul 2021: 50Aug 2021: 60Sep 2021: 45Oct 2021: 60Nov 2021: 56Dec 2021: 592022Jan 2022: 54Feb 2022: 27Mar 2022: 51Apr 2022: 48May 2022: 47Jun 2022: 56Jul 2022: 38Aug 2022: 41Sep 2022: 57Oct 2022: 48Nov 2022: 73Dec 2022: 732023Jan 2023: 55Feb 2023: 66Mar 2023: 87Apr 2023: 55May 2023: 83Jun 2023: 63Jul 2023: 61Aug 2023: 56Sep 2023: 37Oct 2023: 67Nov 2023: 65Dec 2023: 512024Jan 2024: 42Feb 2024: 55Mar 2024: 69Apr 2024: 45May 2024: 61Jun 2024: 56Jul 2024: 84Aug 2024: 84Sep 2024: 55Oct 2024: 56Nov 2024: 62Dec 2024: 482025Jan 2025: 34Feb 2025: 67Mar 2025: 29Apr 2025: 54May 2025: 35Jun 2025: 54Jul 2025: 50Aug 2025: 35Sep 2025: 51Oct 2025: 54Nov 2025: 32Dec 2025: 272026Jan 2026: 31Feb 2026: 46Mar 2026: 53Apr 2026: 43May 2026: 53Jun 2026: 49

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

03737462015: 38220152016: 5322017: 59820172018: 5792019: 44120192020: 4362021: 60820212022: 6132023: 74620232024: 7172025: 52220252026: 275

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Blincyto reports recording the termall reports in the database

  1. Pyrexiafever13%839
  2. Acute lymphocytic leukaemia recurrent7.7%496
  3. Off label useused for a purpose or in a way not on the label6.7%431
  4. Deaththe patient died; cause not stated by this term5.2%333
  5. Headachehead pain3.7%237
  6. Product storage errorthe product was stored wrongly3%193
  7. Tremorshaking2.9%186
  8. Seizurea fit or convulsion2.6%168
  9. Drug ineffectivethe medicine did not work as expected2.3%151
  10. Confusional stateconfusion2.3%149
  11. Circumstance or information capable of leading to medication errora situation that could lead to a medication error2.3%147
  12. Wrong technique in product usage processthe product was used in the wrong way2.2%139
  13. Acute lymphocytic leukaemia2.1%134
  14. Neutropenialow neutrophils, a type of white blood cell2%130
  15. Disease progressionthe disease advanced1.8%113
  16. Infectionan infection, type not specified1.7%108
  17. Blast cell count increased1.6%105
  18. Central nervous system leukaemia1.6%103
  19. Platelet count decreasedlow platelet count1.6%102
  20. Hypotensionlow blood pressure1.6%101
  21. Febrile neutropeniafever with low white blood cells1.4%92
  22. Therapy non-responderthe treatment did not work1.4%90
  23. Nauseafeeling sick1.4%89

Top 30 of 687 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

Death13%836
Life-threatening4.3%275
Hospitalisation (initial or prolonged)23%1,484
Disability0.7%42
Congenital anomaly0%1
Other serious56.8%3,661
Not serious30.1%1,940

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 20.7%46
2 to 115.9%380
12 to 174.1%265
18 to 4418.4%1,184
45 to 6414.2%916
65 to 746.8%436
75 and over3.5%228
Age not given46.4%2,994

Patient sex

Female34.4%2,219
Male39%2,514
Not given26.6%1,716

Who reported

Physician47%3,033
Pharmacist20.9%1,345
Other health professional21.9%1,410
Lawyer0%0
Consumer or non-health professional10.2%655
Not given0.1%6

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 59.7% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Acute lymphocytic leukaemia1,75927.3%
B precursor type acute leukaemia95914.9%
Acute lymphocytic leukaemia recurrent5097.9%
B-cell type acute leukaemia1211.9%
Minimal residual disease851.3%
Acute lymphocytic leukaemia refractory430.7%

The indication field is filled in by the reporter and is often blank; shares are of all 6,449 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Blincyto reports
Dexamethasone2884.5%
Methotrexate1963%
Cytarabine1552.4%
Cyclophosphamide1432.2%
Ponatinib1151.8%
Vincristine1141.8%
Inotuzumab ozogamicin961.5%
Acyclovir741.1%
Prednisone671%
Iclusig651%

Other products listed in reports where Blincyto 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

MeasureBlincytoAll reports
Reports as suspect product6,44920,646,523
Share of that pool—0%
Reports, latest 12 months5241,332,454
Marked serious69.9%57.4%
Death recorded among outcomes, per 1,000 reports13091
Hospitalisation recorded, per 1,000 reports230213
Consumer-filed share10.2%45.8%
Top term, share of reportsPyrexia 13%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."

Questions about Blincyto reports

How many adverse event reports has FDA received for Blincyto?

6,449 reports list Blincyto as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 524 of them arrived in the latest 12 months. Another 117 list it only as a concomitant medication.

What reactions are recorded in Blincyto reports?

pyrexia (13%), cytokine release syndrome (9.2%), acute lymphocytic leukaemia recurrent (7.7%), off label use (6.7%) and neurotoxicity (5.8%). 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 Blincyto was responsible.

How serious are the reports?

69.9% are marked serious by the reporter. Among the outcomes recorded, 13% of reports include death and 23% 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?

physician (47%), other health professional (21.9%) and pharmacist (20.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Blincyto rising?

524 reports in the 12 months to June 2026, down 21% from 662 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 Blincyto 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 Blincyto?

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 Blincyto as a suspect or interacting product; reports listing it only as a concomitant medication (117) 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.