Reported Reactions

Drugs › Microtubule inhibitor

Brand name · Eribulin mesylate

Halaven: adverse event reports filed with FDA

3,156 reports list it as a suspect or interacting product, 2011–2026. Class: Microtubule inhibitor.

3,156
reports as suspect product
0% of all reports · about 205 a year
66
reports, 12 months to June 2026
87 in the 12 months before
93.1%
marked serious by the reporter
88.7% across the class
17.2%
record death among outcomes, as reported
543 reports · not verified by FDA

3,156 adverse event reports received by FDA list the brand name Halaven (eribulin mesylate) as a suspect or interacting product, from February 2011 to June 2026. A further 234 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, 66 reports listed it, down 24% from 87 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 205 reports a year and 0% of the 20,646,523 reports in the database, and 2.1% of the reports for the microtubule inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded neutropenia (15.5%), febrile neutropenia (9.9%) and malignant neoplasm progression (9.6%). A report can list several reactions, so shares add to more than 100%; 275 different terms appear across these reports. Neutropenia is recorded in 15.5% of these reports, a larger share than in the median microtubule inhibitor drug (5.9%).

93.1% of the reports are marked serious by the reporter (88.7% across the class); 17.2% record death among the outcomes and 54.8% record hospitalisation, as reported. 59% of the reports came from physicians, and the largest patient age group is 45 to 64 (43%). 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

02040Jul 2021: 9Aug 2021: 16Sep 2021: 9Oct 2021: 14Nov 2021: 19Dec 2021: 202022Jan 2022: 10Feb 2022: 13Mar 2022: 23Apr 2022: 19May 2022: 17Jun 2022: 19Jul 2022: 21Aug 2022: 23Sep 2022: 24Oct 2022: 16Nov 2022: 27Dec 2022: 182023Jan 2023: 21Feb 2023: 16Mar 2023: 24Apr 2023: 26May 2023: 21Jun 2023: 30Jul 2023: 30Aug 2023: 37Sep 2023: 19Oct 2023: 20Nov 2023: 27Dec 2023: 292024Jan 2024: 40Feb 2024: 26Mar 2024: 20Apr 2024: 16May 2024: 10Jun 2024: 10Jul 2024: 9Aug 2024: 4Sep 2024: 7Oct 2024: 4Nov 2024: 13Dec 2024: 82025Jan 2025: 10Feb 2025: 2Mar 2025: 6Apr 2025: 11May 2025: 6Jun 2025: 7Jul 2025: 17Aug 2025: 4Sep 2025: 6Oct 2025: 5Nov 2025: 5Dec 2025: 32026Jan 2026: 3Feb 2026: 5Mar 2026: 5Apr 2026: 4May 2026: 4Jun 2026: 5

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

01753502011: 7020112012: 2382013: 18420132014: 1262015: 29620152016: 3502017: 31720172018: 2472019: 22320192020: 1442021: 15620212022: 2302023: 30020232024: 1672025: 8220252026: 26

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Halaven reports recording the termmedian drug in microtubule inhibitor

  1. Neutropenialow neutrophils, a type of white blood cell15.5%490
  2. Febrile neutropeniafever with low white blood cells9.9%313
  3. Leukopenialow white blood cells6.1%193
  4. Interstitial lung diseasescarring or inflammation of lung tissue5.5%173
  5. White blood cell count decreasedlow white cell count5.1%160
  6. Pyrexiafever5%157
  7. Neuropathy peripheralnerve damage in hands or feet4.3%135
  8. Nauseafeeling sick3.3%103
  9. Fatiguetiredness3.2%102
  10. Astheniaweakness or lack of energy3.2%100
  11. Pneumonialung infection3.2%100
  12. Anaemialow red blood cells2.9%91
  13. Stomatitissore mouth2.9%90
  14. Vomitingbeing sick2.7%85
  15. Decreased appetitereduced appetite2.6%83
  16. Dyspnoeashortness of breath2.6%81
  17. Thrombocytopenialow platelets2.3%73
  18. Alopeciahair loss2.2%69
  19. Diarrhoealoose or frequent stools2.2%69
  20. Malaisegeneral feeling of being unwell2.1%66
  21. Sepsisa severe body-wide response to infection2%62
  22. Deaththe patient died; cause not stated by this term1.7%53
  23. Platelet count decreasedlow platelet count1.6%52
  24. Headachehead pain1.4%45
  25. Cardiac failureheart failure1.3%42
  26. Pleural effusionfluid around the lung1.3%41

Top 30 of 275 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 4 drugs in the microtubule inhibitor 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

Death17.2%543
Life-threatening5.4%169
Hospitalisation (initial or prolonged)54.8%1,730
Disability2.7%86
Congenital anomaly0%0
Other serious31%977
Not serious6.9%218

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 147,067 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%0
2 to 110%0
12 to 170.1%4
18 to 449.2%290
45 to 6443%1,358
65 to 7417%537
75 and over6.1%192
Age not given24.6%775

Patient sex

Female92%2,902
Male5.3%168
Not given2.7%86

Who reported

Physician59%1,863
Pharmacist7.2%228
Other health professional25.4%801
Lawyer0%1
Consumer or non-health professional6.6%207
Not given1.8%56

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 10.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Breast cancer1,01532.2%
Breast cancer metastatic56317.8%
Breast cancer recurrent41713.2%
Soft tissue sarcoma491.6%
Triple negative breast cancer401.3%
Invasive ductal breast carcinoma280.9%

The indication field is filled in by the reporter and is often blank; shares are of all 3,156 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Halaven reports
Herceptin1464.6%
Xeloda752.4%
Zometa752.4%
Paclitaxel702.2%
Dexamethasone672.1%
Decadron652.1%
Trastuzumab632%
OxyContin561.8%
Perjeta561.8%
Capecitabine541.7%

Other products listed in reports where Halaven 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

MeasureHalavenMicrotubule inhibitorAll reports
Reports as suspect product3,156147,06720,646,523
Share of that pool—2.1%0%
Reports, latest 12 months66—1,332,454
Marked serious93.1%88.7%57.4%
Death recorded among outcomes, per 1,000 reports17214791
Hospitalisation recorded, per 1,000 reports548374213
Consumer-filed share6.6%8.6%45.8%
Top term, share of reportsNeutropenia 15.5%median 5.9%0.6%

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 microtubule inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Paclitaxelgeneric69,3958,41797.4%
Docetaxelgeneric59,4113,17376.9%
Abraxanebrand15,10548393.8%

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 Halaven reports

How many adverse event reports has FDA received for Halaven?

3,156 reports list Halaven as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 66 of them arrived in the latest 12 months. Another 234 list it only as a concomitant medication.

What reactions are recorded in Halaven reports?

neutropenia (15.5%), febrile neutropenia (9.9%), malignant neoplasm progression (9.6%), myelosuppression (8.1%) and leukopenia (6.1%). 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 Halaven was responsible.

How serious are the reports?

93.1% are marked serious by the reporter. Among the outcomes recorded, 17.2% of reports include death and 54.8% 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 (59%), other health professional (25.4%) and pharmacist (7.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Halaven rising?

66 reports in the 12 months to June 2026, down 24% from 87 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 Halaven 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 Halaven?

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 Halaven as a suspect or interacting product; reports listing it only as a concomitant medication (234) 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.