Ruxolitinib (Jakafi/Jakafi XR) is a kinase inhibitor indicated for the treatment of myelofibrosis, polycythemia vera, steroid-refractory acute graft-versus-host disease, and chronic graft-versus-host disease. Jakafi first received FDA approval in November 2011. Most recently, in May 2026, the FDA approved Jakafi extended-release (XR) tablets for the treatment of myelofibrosis, polycythemia vera, and graft-versus-host disease.
Read on to learn more about Jakafi/Jakafi XR including its dosage and administration information, warnings and precautions, and more.
Medication Overview:
- Brand Name: Jakafi
- Generic Name: ruxolitinib
- Treatment for: Myelofibrosis, polycythemia vera, steroid-refractory acute graft-versus-host disease, chronic graft-versus-host disease
- Company: Incyte
- Initial FDA Approval: November 2011
| Indicated Condition | Indication | Age | Date Approved |
|---|---|---|---|
| Intermediate or High-Risk Myelofibrosis/Primary Myelofibrosis/Post-Polycythemia Vera Myelofibrosis/Post-Essential Thrombocythemia Myelofibrosis | Indicated for the treatment of intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis in adults. | Adults | November 2011 |
| Polycythemia Vera | Indicated for the treatment of polycythemia vera in adults who have had an inadequate response to or are intolerant of hydroxyurea. | Adults | December 2014 |
| Steroid-Refractory Acute Graft-Versus-Host Disease | Indicated for the treatment of steroid-refractory acute graft-versus-host disease in adult and pediatric patients 12 years and older. | Adults & Patients 12 and Older | May 2019 |
| Chronic Graft-Versus-Host Disease | Indicated for the treatment of chronic graft-versus-host disease after failure of one or two lines of systemic therapy in adult and pediatric patients 12 years and older. | Adults & Patients 12 and Older | September 2021 |
Warnings and Precautions:
- Thrombocytopenia, Anemia, and Neutropenia: Manage by dose reduction or interruption, or transfusion.
- Risk of Infection: Assess patients for signs and symptoms of infection and initiate appropriate treatment promptly. Serious infections should have resolved before starting therapy with Jakafi/Jakafi XR.
- Symptom Exacerbation Following Interruption or Discontinuation: Manage with supportive care and consider resuming treatment with Jakafi/Jakafi XR.
- Risk of Non-Melanoma Skin Cancer: Perform periodic skin examinations.
- Lipid Elevations: Assess lipid levels 8 to 12 weeks from start of therapy and treat as needed.
- Major Adverse Cardiovascular Events (MACE): Monitor for development of MACE.
- Thrombosis: Evaluate and treat symptoms of thrombosis promptly.
- Secondary Malignancies: Monitor for development of secondary malignancies, particularly in patients who are current or past smokers.
Dosage and Administration:
Doses should be individualized based on safety and efficacy. Starting doses per indication are noted below.
Myelofibrosis: The starting dose of JAKAFI/JAKAFI XR is based on patient’s baseline platelet count:
- Greater than 200 × 109/L: JAKAFI 20 mg given orally twice daily or JAKAFI XR 44 mg given orally once daily.
- 100 x 109/L to 200 x 109/L: JAKAFI 15 mg given orally twice daily or JAKAFI XR 33 mg given orally once daily.
- 50 x 109/L to less than 100 x 109/L: JAKAFI 5 mg given orally twice daily or JAKAFI XR 11 mg given orally once daily.
Polycythemia Vera: The starting dose of Jakafi is 10 mg given orally twice daily or Jakafi XR 22 mg given orally once daily.
Acute Graft-Versus-Host Disease: The starting dose of Jakafi is 5 mg given orally twice daily or Jakafi XR 11 mg given orally once daily.
Chronic Graft-Versus-Host Disease The starting dose of Jakafi is 10 mg given orally twice daily or Jakafi XR 22 mg given orally once daily.
Contraindications:
None.
Drug Interactions:
Fluconazole: Avoid concomitant use with fluconazole doses greater than 200 mg. Reduce JAKAFI/JAKAFI XR dosage with fluconazole doses less than or equal to 200 mg.
Strong CYP3A4 Inhibitors: Reduce, interrupt, or discontinue JAKAFI/JAKAFI XR doses as recommended except in patients with acute or chronic graft-versus-host-disease.
Adverse Reactions:
- In myelofibrosis and polycythemia vera, the most common hematologic adverse reactions (incidence > 20%) are thrombocytopenia and anemia. The most common nonhematologic adverse reactions (incidence ≥ 15%) are bruising, dizziness, headache, and diarrhea.
- In acute graft-versus-host disease, the most common hematologic adverse reactions (incidence > 50%) are anemia, thrombocytopenia, and neutropenia. The most common nonhematologic adverse reactions (incidence > 50%) are infections (pathogen not specified) and edema.
- In chronic graft-versus-host disease, the most common hematologic adverse reactions (incidence > 35%) are anemia and thrombocytopenia. The most common nonhematologic adverse reactions (incidence ≥ 20%) are infections (pathogen not specified) and viral infections.
Related Guidelines:
- Management of Acute Graft-Versus-Host Disease
- American Society for Transplantation and Cellular Therapy
- May 2026
- Management of Myelofibrosis
- British Society for Haematology
- December 2023
- Diagnosis and Evaluation of Prognosis of Myelofibrosis
- British Society for Haematology
- November 2023
Please note: This article is current as of July 10, 2026. Consult our clinical guidelines library or drug information tool to ensure you always have the most up-to-date information.
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