Reported Reactions

Drugs › Kinase inhibitor

Generic name

Tucatinib: adverse event reports filed with FDA

2,125 reports list it as a suspect or interacting product, 2017–2026. Class: Kinase inhibitor.

2,125
reports as suspect product
0% of all reports · about 232 a year
143
reports, 12 months to June 2026
424 in the 12 months before
95.4%
marked serious by the reporter
70.8% across the class
16.2%
record death among outcomes, as reported
345 reports · not verified by FDA

2,125 adverse event reports received by FDA list tucatinib, a generic name as a suspect or interacting product, from May 2017 to June 2026. A further 122 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, 143 reports listed it, down 66% from 424 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 232 reports a year and 0% of the 20,646,523 reports in the database, and 0.3% of the reports for the kinase 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 diarrhoea (18.6%), nausea (12.1%) and fatigue (10.8%). A report can list several reactions, so shares add to more than 100%; 511 different terms appear across these reports. Diarrhoea is recorded in 18.6% of these reports, a larger share than in the median kinase inhibitor drug (6.9%).

95.4% of the reports are marked serious by the reporter (70.8% across the class); 16.2% record death among the outcomes and 50.6% record hospitalisation, as reported. 50.4% of the reports came from physicians, and the largest patient age group is 45 to 64 (29.5%). 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

03875Jul 2021: 74Aug 2021: 54Sep 2021: 33Oct 2021: 22Nov 2021: 25Dec 2021: 202022Jan 2022: 8Feb 2022: 16Mar 2022: 19Apr 2022: 31May 2022: 27Jun 2022: 27Jul 2022: 22Aug 2022: 40Sep 2022: 25Oct 2022: 30Nov 2022: 21Dec 2022: 392023Jan 2023: 32Feb 2023: 21Mar 2023: 42Apr 2023: 24May 2023: 52Jun 2023: 33Jul 2023: 26Aug 2023: 28Sep 2023: 39Oct 2023: 42Nov 2023: 22Dec 2023: 232024Jan 2024: 31Feb 2024: 37Mar 2024: 32Apr 2024: 26May 2024: 38Jun 2024: 24Jul 2024: 75Aug 2024: 52Sep 2024: 38Oct 2024: 18Nov 2024: 40Dec 2024: 232025Jan 2025: 48Feb 2025: 35Mar 2025: 25Apr 2025: 31May 2025: 11Jun 2025: 28Jul 2025: 15Aug 2025: 18Sep 2025: 14Oct 2025: 12Nov 2025: 11Dec 2025: 82026Jan 2026: 12Feb 2026: 12Mar 2026: 6Apr 2026: 6May 2026: 18Jun 2026: 11

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

02715422017: 120172018: 320182019: 320192020: 13220202021: 54220212022: 30520222023: 38420232024: 43420242025: 25620252026: 652026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Tucatinib reports recording the termmedian drug in kinase inhibitor

  1. Diarrhoealoose or frequent stools18.6%395
  2. Nauseafeeling sick12.1%258
  3. Fatiguetiredness10.8%230
  4. Deaththe patient died; cause not stated by this term7.8%165
  5. Vomitingbeing sick7.7%164
  6. Off label useused for a purpose or in a way not on the label5.5%116
  7. Dehydrationdehydration5.4%115
  8. Hospitalisationadmission to hospital5.3%112
  9. Astheniaweakness or lack of energy5.2%111
  10. Product dose omission issuea dose was missed4.9%104
  11. Disease progressionthe disease advanced4.8%103
  12. Pneumonialung infection3.4%73
  13. Decreased appetitereduced appetite3.4%72
  14. Headachehead pain3.3%71
  15. Acute kidney injurysudden loss of kidney function3.3%70
  16. Back painback pain3.2%69
  17. Sepsisa severe body-wide response to infection3.1%66
  18. Drug ineffectivethe medicine did not work as expected3.1%65
  19. Thrombocytopenialow platelets2.9%62
  20. Pleural effusionfluid around the lung2.6%56
  21. Blood creatinine increasedraised creatinine, a kidney test2.6%55
  22. Vascular device infection2.5%54
  23. Covid-19COVID-19 infection2.4%52

Top 30 of 511 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 100 drugs in the kinase 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

Death16.2%345
Life-threatening2%43
Hospitalisation (initial or prolonged)50.6%1,076
Disability1.2%26
Congenital anomaly0.5%11
Other serious55.9%1,188
Not serious4.6%97

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 849,161 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 20.2%5
2 to 110%0
12 to 170%0
18 to 4411%234
45 to 6429.5%627
65 to 7414.2%301
75 and over3.8%80
Age not given41.3%878

Patient sex

Female82.3%1,749
Male7%149
Not given10.7%227

Who reported

Physician50.4%1,072
Pharmacist1.5%31
Other health professional20.8%443
Lawyer0%0
Consumer or non-health professional27.2%578
Not given0%1

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 49.9% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Her2 positive breast cancer49123.1%
Breast cancer female46922.1%
Breast cancer metastatic24211.4%
Breast cancer1848.7%
Colorectal cancer metastatic502.4%
Invasive breast carcinoma291.4%

The indication field is filled in by the reporter and is often blank; shares are of all 2,125 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Tucatinib reports
Trastuzumab99646.9%
Capecitabine96545.4%
Ado-trastuzumab emtansine24911.7%
Pertuzumab24911.7%
Dexamethasone2049.6%
Herceptin1888.8%
Zofran1808.5%
Acetaminophen1677.9%
Xeloda1577.4%
Xgeva1436.7%

Other products listed in reports where Tucatinib 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

MeasureTucatinibKinase inhibitorAll reports
Reports as suspect product2,125849,16120,646,523
Share of that pool—0.3%0%
Reports, latest 12 months143—1,332,454
Marked serious95.4%70.8%57.4%
Death recorded among outcomes, per 1,000 reports16219091
Hospitalisation recorded, per 1,000 reports506264213
Consumer-filed share27.2%42.3%45.8%
Top term, share of reportsDiarrhoea 18.6%median 6.9%3.1%

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 kinase inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Ibrancebrand81,9122,38047.1%
Imbruvicabrand67,0392,28374.4%
Cabometyxbrand41,8184,90440.4%
Sutentbrand33,21517574.5%
Afinitorbrand30,70616171.3%
Sprycelbrand27,25555749.7%
Tasignabrand24,91132870.9%
Kisqalibrand24,6033,41379.2%
Ofevbrand23,9072,43466.9%
Gleevecbrand23,1328174.7%
Tagrissobrand23,0851,41092.3%
Lenvimabrand22,3502,64387.3%
Votrientbrand22,08411960.9%
Mekinistbrand17,07091664%
Inlytabrand15,69638860.9%

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 Tucatinib reports

How many adverse event reports has FDA received for Tucatinib?

2,125 reports list Tucatinib as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 143 of them arrived in the latest 12 months. Another 122 list it only as a concomitant medication.

What reactions are recorded in Tucatinib reports?

diarrhoea (18.6%), nausea (12.1%), fatigue (10.8%), death (7.8%) and vomiting (7.7%). 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 Tucatinib was responsible.

How serious are the reports?

95.4% are marked serious by the reporter. Among the outcomes recorded, 16.2% of reports include death and 50.6% 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 (50.4%), consumer or non-health professional (27.2%) and other health professional (20.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Tucatinib rising?

143 reports in the 12 months to June 2026, down 66% from 424 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 Tucatinib 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 Tucatinib?

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 Tucatinib as a suspect or interacting product; reports listing it only as a concomitant medication (122) 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.