Jakafiruxolitinib
According to the FDA label: JAKAFI/JAKAFI XR is a kinase inhibitor indicated for treatment of: intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis in adults. ( 1.1 ) polycythemia vera in adults who have had an inadequate response to or are intolerant of hydroxyurea. ( 1.2 ) steroid-refractory acute graft-versus-host disease in adult and pediatric patients 12 years and older.
65,338 adverse event reports submitted to the FDA (2012–2026)
Top Reported Adverse Events
The most frequently reported events in association with Jakafi in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
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Off Label Use 13,158 reports
Using a medication for a condition or in a way that the FDA has not officially approved. This is common and often legal, and a report of it does not mean something went wrong. Doctors sometimes prescribe drugs off label based on their judgment.
Full definition in the glossary →Death 6,278 reports
A report that the person died. A death appearing in reports for a drug does not mean the drug caused it. Reports record that a death occurred while the medication was being used, which can happen for many unrelated reasons.
Full definition in the glossary →Fatigue 5,915 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Anaemia 3,030 reports
A condition where there are too few healthy red blood cells to carry enough oxygen, often causing tiredness and paleness. Also spelled anemia in American English.
Full definition in the glossary → See all drugs reporting this event →Haemoglobin Decreased 2,932 reports
A blood test result showing a low level of haemoglobin, the protein in red blood cells that carries oxygen. This is closely related to anaemia. Also spelled hemoglobin in American English.
Full definition in the glossary →Platelet Count Decreased 2,665 reports
A blood test result showing a low level of platelets, the cells that help blood clot. This is the lab-measurement version of thrombocytopenia.
Full definition in the glossary →Diarrhoea 2,602 reports
Loose or watery bowel movements, often frequent. Also spelled diarrhea in American English.
Full definition in the glossary → See all drugs reporting this event →Asthenia 2,470 reports
Physical weakness or lack of strength.
Full definition in the glossary →Dizziness 2,430 reports
A feeling of being lightheaded, unsteady, or like the room is spinning.
Full definition in the glossary → See all drugs reporting this event →Headache 2,309 reports
Pain in the head or upper neck.
Full definition in the glossary → See all drugs reporting this event →Product Dose Omission Issue 2,254 reports
A report that a dose of the medication was missed or skipped.
Full definition in the glossary →Pneumonia 2,106 reports
An infection that inflames the air sacs in the lungs, which can cause cough, fever, and difficulty breathing.
Full definition in the glossary →Nausea 2,051 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →Weight Increased 1,931 reports
- Product Availability Issue 1,925 reports
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Male | 10,334 |
| Female | 9,376 |
| Unknown | 178 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 1,628 |
| 18-34 | 985 |
| 35-49 | 1,271 |
| 50-64 | 3,976 |
| 65-74 | 5,033 |
| 75+ | 5,268 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Jakafi. A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Non-Serious | 31,891 |
| Other Serious | 23,651 |
| Hospitalization | 13,140 |
| Death | 9,610 |
| Life-Threatening | 1,027 |
| Disability | 254 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Jakafi. Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 2012 | 483 |
| 2013 | 839 |
| 2014 | 2,779 |
| 2015 | 2,508 |
| 2016 | 4,603 |
| 2017 | 4,333 |
| 2018 | 5,003 |
| 2019 | 5,205 |
| 2020 | 6,093 |
| 2021 | 6,475 |
| 2022 | 6,432 |
| 2023 | 6,566 |
| 2024 | 6,201 |
| 2025 | 6,122 |
| 2026 (partial) | 1,696 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Jakafi
In FDA adverse event reports that mention Jakafi, these medications appeared most often in the same report.
- Aspirin (5,013 reports)
- Prednisone (4,005 reports)
- Hydroxyurea (3,904 reports)
- Allopurinol (3,901 reports)
- Omeprazole (3,616 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026