Reported Reactions

Drugs › Kinase inhibitor

Brand name · Neratinib

Nerlynx: adverse event reports filed with FDA

1,696 reports list it as a suspect or interacting product, 2015–2026. Class: Kinase inhibitor.

1,696
reports as suspect product
0% of all reports · about 150 a year
48
reports, 12 months to June 2026
73 in the 12 months before
49.1%
marked serious by the reporter
70.8% across the class
12.9%
record death among outcomes, as reported
219 reports · not verified by FDA

Between March 2015 and June 2026, 1,696 adverse event reports received by FDA list the brand name Nerlynx (neratinib) as a suspect or interacting product. Reports that mention it only as a concomitant medication (41) are left out of every figure here.

In the 12 months to June 2026, 48 reports listed it, down 34% from 73 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 150 reports a year and 0% of the 20,646,523 reports in the database, and 0.2% 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.

The MedDRA terms listed most often are diarrhoea (59.3%), nausea (26.4%) and fatigue (22.3%). A report can list several reactions, so shares add to more than 100%; 276 different terms appear across these reports. Diarrhoea is recorded in 59.3% of these reports, a larger share than in the median kinase inhibitor drug (6.9%).

49.1% of the reports are marked serious by the reporter (70.8% across the class); 12.9% record death among the outcomes and 23.3% record hospitalisation, as reported. 45.6% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (2.5%). 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

03978Jul 2021: 9Aug 2021: 6Sep 2021: 78Oct 2021: 9Nov 2021: 5Dec 2021: 42022Jan 2022: 3Feb 2022: 5Mar 2022: 4Apr 2022: 2May 2022: 2Jun 2022: 10Jul 2022: 4Aug 2022: 22Sep 2022: 3Oct 2022: 7Nov 2022: 9Dec 2022: 102023Jan 2023: 2Feb 2023: 5Mar 2023: 5Apr 2023: 4May 2023: 5Jun 2023: 9Jul 2023: 7Aug 2023: 18Sep 2023: 5Oct 2023: 3Nov 2023: 3Dec 2023: 72024Jan 2024: 5Feb 2024: 6Mar 2024: 7Apr 2024: 3May 2024: 6Jun 2024: 9Jul 2024: 10Aug 2024: 3Sep 2024: 12Oct 2024: 6Nov 2024: 4Dec 2024: 42025Jan 2025: 14Feb 2025: 5Mar 2025: 3Apr 2025: 4May 2025: 2Jun 2025: 6Jul 2025: 2Aug 2025: 10Sep 2025: 7Oct 2025: 4Nov 2025: 1Dec 2025: 52026Jan 2026: 2Feb 2026: 5Mar 2026: 0Apr 2026: 5May 2026: 3Jun 2026: 4

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

03567112015: 220152017: 1382018: 71120182019: 1842020: 20820202021: 1422022: 8120222023: 732024: 7520242025: 632026: 192026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Nerlynx reports recording the termmedian drug in kinase inhibitor

  1. Diarrhoealoose or frequent stools59.3%1,005
  2. Nauseafeeling sick26.4%448
  3. Fatiguetiredness22.3%378
  4. Off label useused for a purpose or in a way not on the label14.3%243
  5. Vomitingbeing sick13.4%227
  6. Constipationconstipation13.1%223
  7. Decreased appetitereduced appetite10.6%179
  8. Deaththe patient died; cause not stated by this term10.2%173
  9. Dehydrationdehydration7.3%123
  10. Abdominal painstomach or belly pain5.5%93
  11. Headachehead pain5.4%91
  12. Astheniaweakness or lack of energy5.2%89
  13. Hospitalisationadmission to hospital5.2%88
  14. Abdominal pain upperupper stomach pain5.1%87
  15. Dizzinesslight-headedness or unsteadiness5.1%86
  16. Rashskin rash4.8%82
  17. Weight decreasedweight loss4.7%80
  18. Abdominal discomfortstomach discomfort4%67
  19. Underdoseless than the intended dose3.9%66
  20. Muscle spasmsmuscle cramps3.8%65
  21. Dyspepsiaindigestion3.8%64
  22. Abdominal distensiona bloated abdomen3.4%57
  23. Disease progressionthe disease advanced3.4%57
  24. Malaisegeneral feeling of being unwell3.2%55
  25. Product dose omission issuea dose was missed3.2%54
  26. Drug dose omissiona dose was missed2.5%42
  27. Drug titration2.4%41
  28. Dry mouthdry mouth2.2%38

Top 30 of 276 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

Death12.9%219
Life-threatening0.7%12
Hospitalisation (initial or prolonged)23.3%395
Disability0.2%4
Congenital anomaly0%0
Other serious23.2%394
Not serious50.9%864

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%0
2 to 110%0
12 to 170%0
18 to 441.2%20
45 to 642.5%42
65 to 741.1%19
75 and over0.4%7
Age not given94.8%1,608

Patient sex

Female5.4%92
Male0.1%1
Not given94.5%1,603

Who reported

Physician7.8%132
Pharmacist32.4%550
Other health professional45.6%774
Lawyer0.2%3
Consumer or non-health professional13.4%228
Not given0.5%9

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 84.4% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Breast cancer54832.3%
Breast cancer female35921.2%
Her2 positive breast cancer1347.9%
Breast cancer metastatic885.2%
Her-2 positive breast cancer613.6%
Neoplasm malignant100.6%

The indication field is filled in by the reporter and is often blank; shares are of all 1,696 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Nerlynx reports
Loperamide21112.4%
Imodium20111.9%
Capecitabine1106.5%
Gabapentin734.3%
Anastrozole694.1%
Ergocalciferol653.8%
Tamoxifen593.5%
Letrozole523.1%
Dexamethasone502.9%
Zofran462.7%

Other products listed in reports where Nerlynx 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

MeasureNerlynxKinase inhibitorAll reports
Reports as suspect product1,696849,16120,646,523
Share of that pool—0.2%0%
Reports, latest 12 months48—1,332,454
Marked serious49.1%70.8%57.4%
Death recorded among outcomes, per 1,000 reports12919091
Hospitalisation recorded, per 1,000 reports233264213
Consumer-filed share13.4%42.3%45.8%
Top term, share of reportsDiarrhoea 59.3%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 Nerlynx reports

How many adverse event reports has FDA received for Nerlynx?

1,696 reports list Nerlynx as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 48 of them arrived in the latest 12 months. Another 41 list it only as a concomitant medication.

What reactions are recorded in Nerlynx reports?

diarrhoea (59.3%), nausea (26.4%), fatigue (22.3%), off label use (14.3%) and vomiting (13.4%). 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 Nerlynx was responsible.

How serious are the reports?

49.1% are marked serious by the reporter. Among the outcomes recorded, 12.9% of reports include death and 23.3% 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?

other health professional (45.6%), pharmacist (32.4%) and consumer or non-health professional (13.4%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Nerlynx rising?

48 reports in the 12 months to June 2026, down 34% from 73 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 Nerlynx 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 Nerlynx?

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 Nerlynx as a suspect or interacting product; reports listing it only as a concomitant medication (41) 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.