Fedratinib
Fedratinib is an oral kinase inhibitor used to treat adults with intermediate-2 or high-risk primary myelofibrosis, as well as post-polycythemia vera and post-essential thrombocythemia myelofibrosis. It works by selectively inhibiting JAK2 and FLT3 enzymes, which are involved in the signaling pathways that drive abnormal blood cell production in myelofibrosis. This medication helps reduce spleen size and improve myelofibrosis-related symptoms.
Fedratinib is a JAK2-selective oral kinase inhibitor used to treat myelofibrosis by targeting abnormal signaling pathways in blood cells.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- L01EJ02
- RxNorm
- 2197490
- Generic
- Fedratinib
- Class
- atc-l01
- Brands
- Inrebic
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment of adults with intermediate-2 or high-risk primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. It is typically used in patients who have not responded adequately to or cannot receive ruxolitinib.
Fedratinib is a selective inhibitor of Janus Associated Kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3). It targets both wild type and mutationally activated JAK2, blocking overactive JAK-STAT signaling pathways that drive abnormal blood cell production, inflammation, and fibrosis in myeloproliferative neoplasms.
Fedratinib carries a boxed warning for serious and fatal encephalopathy, including Wernicke's encephalopathy, due to thiamine deficiency. Regular monitoring of thiamine levels is required. Common side effects include anemia, thrombocytopenia, nausea, vomiting, diarrhea, and elevated liver enzymes. Patients should have baseline and periodic blood counts and liver function tests during treatment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy