Brand name · Palbociclib
Ibrance: adverse event reports filed with FDA
81,912 reports list it as a suspect or interacting product, 2012–2026. Class: Kinase inhibitor.
- 81,912
- reports as suspect product
- 0.4% of all reports · about 5,685 a year
- 2,380
- reports, 12 months to June 2026
- 4,310 in the 12 months before
- 47.1%
- marked serious by the reporter
- 70.8% across the class
- 10.3%
- record death among outcomes, as reported
- 8,468 reports · not verified by FDA
Between February 2012 and June 2026, 81,912 adverse event reports received by FDA list the brand name Ibrance (palbociclib) as a suspect or interacting product. Reports that mention it only as a concomitant medication (2,023) are left out of every figure here.
In the 12 months to June 2026, 2,380 reports listed it, down 45% from 4,310 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 5,685 reports a year and 0.4% of the 20,646,523 reports in the database, and 9.6% 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 fatigue (17.9%), white blood cell count decreased (13.1%) and neoplasm progression (11.6%). A report can list several reactions, so shares add to more than 100%; 2,264 different terms appear across these reports. Fatigue is recorded in 17.9% of these reports, a larger share than in the median kinase inhibitor drug (5.7%).
47.1% of the reports are marked serious by the reporter (70.8% across the class); 10.3% record death among the outcomes and 12.8% record hospitalisation, as reported. 42.5% of the reports came from consumers, and the largest patient age group is 45 to 64 (31.1%). 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
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
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Ibrance reports recording the termmedian drug in kinase inhibitor
- Fatiguetiredness17.9%14,658
- White blood cell count decreasedlow white cell count13.1%10,742
- Neoplasm progression11.6%9,512
- Nauseafeeling sick9.4%7,729
- Deaththe patient died; cause not stated by this term8.2%6,698
- Alopeciahair loss7.4%6,096
- Diarrhoealoose or frequent stools6.6%5,371
- Neutropenialow neutrophils, a type of white blood cell6.1%4,967
- Decreased appetitereduced appetite3.9%3,158
- Malaisegeneral feeling of being unwell3.8%3,111
- Astheniaweakness or lack of energy3.8%3,101
- Off label useused for a purpose or in a way not on the label3.8%3,100
- Painpain, site not specified3.7%3,053
- Dyspnoeashortness of breath3.4%2,781
- Vomitingbeing sick3.3%2,689
- Stomatitissore mouth3.3%2,668
- Arthralgiajoint pain3.3%2,665
- Constipationconstipation3.1%2,534
- Headachehead pain3.1%2,503
- Dizzinesslight-headedness or unsteadiness2.8%2,290
- Product dose omission issuea dose was missed2.6%2,128
- Rashskin rash2.5%2,054
- Coughcough2.5%2,032
- Full blood count decreased2.4%1,927
- Platelet count decreasedlow platelet count2.3%1,904
- Disease progressionthe disease advanced2.3%1,888
- Neutrophil count decreased2.3%1,865
- Hot flusha hot flush2.2%1,804
- Weight decreasedweight loss2.1%1,753
- Anaemialow red blood cells2.1%1,696
Top 30 of 2,264 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
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
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 84.2% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Breast cancer female | 16,259 | 19.8% |
| Breast cancer metastatic | 12,473 | 15.2% |
| Breast cancer | 10,387 | 12.7% |
| Neoplasm malignant | 1,839 | 2.2% |
| Breast cancer stage iv | 879 | 1.1% |
| Bone cancer | 229 | 0.3% |
The indication field is filled in by the reporter and is often blank; shares are of all 81,912 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Ibrance reports |
|---|---|---|
| Letrozole | 13,528 | 16.5% |
| Faslodex | 6,996 | 8.5% |
| Fulvestrant | 3,114 | 3.8% |
| Ergocalciferol | 2,909 | 3.6% |
| Xgeva | 2,871 | 3.5% |
| Anastrozole | 2,603 | 3.2% |
| Femara | 1,906 | 2.3% |
| Gabapentin | 1,681 | 2.1% |
| Calcium | 1,615 | 2% |
| Aspirin | 1,610 | 2% |
Other products listed in reports where Ibrance 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
| Measure | Ibrance | Kinase inhibitor | All reports |
|---|---|---|---|
| Reports as suspect product | 81,912 | 849,161 | 20,646,523 |
| Share of that pool | — | 9.6% | 0.4% |
| Reports, latest 12 months | 2,380 | — | 1,332,454 |
| Marked serious | 47.1% | 70.8% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 103 | 190 | 91 |
| Hospitalisation recorded, per 1,000 reports | 128 | 264 | 213 |
| Consumer-filed share | 42.5% | 42.3% | 45.8% |
| Top term, share of reports | Fatigue 17.9% | median 5.7% | 3.7% |
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
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Imbruvica | brand | 67,039 | 2,283 | 74.4% |
| Cabometyx | brand | 41,818 | 4,904 | 40.4% |
| Sutent | brand | 33,215 | 175 | 74.5% |
| Afinitor | brand | 30,706 | 161 | 71.3% |
| Sprycel | brand | 27,255 | 557 | 49.7% |
| Tasigna | brand | 24,911 | 328 | 70.9% |
| Kisqali | brand | 24,603 | 3,413 | 79.2% |
| Ofev | brand | 23,907 | 2,434 | 66.9% |
| Gleevec | brand | 23,132 | 81 | 74.7% |
| Tagrisso | brand | 23,085 | 1,410 | 92.3% |
| Lenvima | brand | 22,350 | 2,643 | 87.3% |
| Votrient | brand | 22,084 | 119 | 60.9% |
| Mekinist | brand | 17,070 | 916 | 64% |
| Inlyta | brand | 15,696 | 388 | 60.9% |
| Nexavar | brand | 15,449 | 67 | 87.5% |
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 Ibrance reports
How many adverse event reports has FDA received for Ibrance?
81,912 reports list Ibrance as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 2,380 of them arrived in the latest 12 months. Another 2,023 list it only as a concomitant medication.
What reactions are recorded in Ibrance reports?
fatigue (17.9%), white blood cell count decreased (13.1%), neoplasm progression (11.6%), nausea (9.4%) and death (8.2%). 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 Ibrance was responsible.
How serious are the reports?
47.1% are marked serious by the reporter. Among the outcomes recorded, 10.3% of reports include death and 12.8% 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?
consumer or non-health professional (42.5%), other health professional (29.2%) and physician (13.5%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Ibrance rising?
2,380 reports in the 12 months to June 2026, down 45% from 4,310 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 Ibrance 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 Ibrance?
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 Ibrance as a suspect or interacting product; reports listing it only as a concomitant medication (2,023) 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.