Reported Reactions

Drugs › Kinase inhibitor

Generic name

Palbociclib: adverse event reports filed with FDA

9,939 reports list it as a suspect or interacting product, 2012–2026. Class: Kinase inhibitor. Also reported as Palbociclib Capsule, Palbociclib /08402602/.

9,939
reports as suspect product
0.1% of all reports · about 714 a year
698
reports, 12 months to June 2026
752 in the 12 months before
96.2%
marked serious by the reporter
70.8% across the class
18.9%
record death among outcomes, as reported
1,877 reports · not verified by FDA

Between August 2012 and June 2026, 9,939 adverse event reports received by FDA list palbociclib, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (1,195) are left out of every figure here.

In the 12 months to June 2026, 698 reports listed it, close to the 752 of 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 714 reports a year and 0.1% of the 20,646,523 reports in the database, and 1.2% 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 reactions recorded most often are neutropenia (16.5%), death (10.9%) and neoplasm progression (10.8%). A report can list several reactions, so shares add to more than 100%; 1,290 different terms appear across these reports. Neutropenia is recorded in 16.5% of these reports, a larger share than in the median kinase inhibitor drug (0.7%).

96.2% of the reports are marked serious by the reporter (70.8% across the class); 18.9% record death among the outcomes and 33.3% record hospitalisation, as reported. 45.9% of the reports came from physicians, and the largest patient age group is 45 to 64 (33.1%). 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

0142283Jul 2021: 86Aug 2021: 119Sep 2021: 103Oct 2021: 122Nov 2021: 126Dec 2021: 1162022Jan 2022: 100Feb 2022: 90Mar 2022: 120Apr 2022: 153May 2022: 138Jun 2022: 134Jul 2022: 121Aug 2022: 129Sep 2022: 115Oct 2022: 101Nov 2022: 130Dec 2022: 1322023Jan 2023: 114Feb 2023: 98Mar 2023: 104Apr 2023: 78May 2023: 105Jun 2023: 102Jul 2023: 88Aug 2023: 102Sep 2023: 91Oct 2023: 124Nov 2023: 185Dec 2023: 2832024Jan 2024: 89Feb 2024: 115Mar 2024: 96Apr 2024: 93May 2024: 86Jun 2024: 72Jul 2024: 70Aug 2024: 60Sep 2024: 72Oct 2024: 76Nov 2024: 54Dec 2024: 732025Jan 2025: 76Feb 2025: 66Mar 2025: 50Apr 2025: 55May 2025: 55Jun 2025: 45Jul 2025: 67Aug 2025: 69Sep 2025: 61Oct 2025: 91Nov 2025: 100Dec 2025: 542026Jan 2026: 38Feb 2026: 48Mar 2026: 36Apr 2026: 38May 2026: 55Jun 2026: 41

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

07371,4742012: 220122014: 132015: 20320152016: 5202017: 60320172018: 5852019: 85820192020: 1,0512021: 1,16620212022: 1,4632023: 1,47420232024: 9562025: 78920252026: 256

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Palbociclib reports recording the termmedian drug in kinase inhibitor

  1. Neutropenialow neutrophils, a type of white blood cell16.5%1,639
  2. Deaththe patient died; cause not stated by this term10.9%1,082
  3. Fatiguetiredness7.7%761
  4. White blood cell count decreasedlow white cell count6.4%632
  5. Astheniaweakness or lack of energy5.9%591
  6. Nauseafeeling sick5.7%570
  7. Haemoglobin decreasedlow haemoglobin5.6%553
  8. Anaemialow red blood cells5.3%527
  9. Thrombocytopenialow platelets4.6%461
  10. Diarrhoealoose or frequent stools4.2%422
  11. Dyspnoeashortness of breath4.2%416
  12. Pyrexiafever4%396
  13. Off label useused for a purpose or in a way not on the label3.9%388
  14. Platelet count decreasedlow platelet count3.9%385
  15. Vomitingbeing sick3.6%362
  16. Leukopenialow white blood cells3.6%354
  17. Arthralgiajoint pain3.2%323
  18. Painpain, site not specified3.2%317
  19. General physical health deteriorationgeneral decline in health2.8%274
  20. Breast cancerbreast cancer2.7%264
  21. Drug ineffectivethe medicine did not work as expected2.7%264
  22. Disease progressionthe disease advanced2.6%259
  23. Decreased appetitereduced appetite2.6%255
  24. Coughcough2.3%225

Top 30 of 1,290 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

Death18.9%1,877
Life-threatening4.2%421
Hospitalisation (initial or prolonged)33.3%3,311
Disability1.1%109
Congenital anomaly0%1
Other serious67.1%6,668
Not serious3.8%380

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%1
2 to 110.2%23
12 to 170.1%12
18 to 447.7%764
45 to 6433.1%3,288
65 to 7421.1%2,094
75 and over15%1,493
Age not given22.8%2,264

Patient sex

Female88.3%8,779
Male4.2%417
Not given7.5%743

Who reported

Physician45.9%4,564
Pharmacist2.1%205
Other health professional24.5%2,434
Lawyer0%2
Consumer or non-health professional26.4%2,621
Not given1.1%113

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 19.2% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Breast cancer metastatic2,72627.4%
Breast cancer2,05920.7%
Breast cancer female2842.9%
Hormone receptor positive her2 negative breast cancer2382.4%
Invasive ductal breast carcinoma1721.7%
Breast cancer stage iv1091.1%

The indication field is filled in by the reporter and is often blank; shares are of all 9,939 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Palbociclib reports
Letrozole4,13141.6%
Fulvestrant2,54425.6%
Zoledronic acid7497.5%
Denosumab6796.8%
Exemestane5685.7%
Faslodex5675.7%
Anastrozole5395.4%
Capecitabine5145.2%
Xgeva5035.1%
Femara4704.7%

Other products listed in reports where Palbociclib 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

MeasurePalbociclibKinase inhibitorAll reports
Reports as suspect product9,939849,16120,646,523
Share of that pool—1.2%0.1%
Reports, latest 12 months698—1,332,454
Marked serious96.2%70.8%57.4%
Death recorded among outcomes, per 1,000 reports18919091
Hospitalisation recorded, per 1,000 reports333264213
Consumer-filed share26.4%42.3%45.8%
Top term, share of reportsNeutropenia 16.5%median 0.7%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 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 Palbociclib reports

How many adverse event reports has FDA received for Palbociclib?

9,939 reports list Palbociclib as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 698 of them arrived in the latest 12 months. Another 1,195 list it only as a concomitant medication.

What reactions are recorded in Palbociclib reports?

neutropenia (16.5%), death (10.9%), neoplasm progression (10.8%), malignant neoplasm progression (9%) and fatigue (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 Palbociclib was responsible.

How serious are the reports?

96.2% are marked serious by the reporter. Among the outcomes recorded, 18.9% of reports include death and 33.3% 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?

physician (45.9%), consumer or non-health professional (26.4%) and other health professional (24.5%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Palbociclib rising?

698 reports in the 12 months to June 2026, close to the 752 of 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 Palbociclib 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 Palbociclib?

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 Palbociclib as a suspect or interacting product; reports listing it only as a concomitant medication (1,195) 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.