Momelotinib
Momelotinib is an oral medication classified as a Janus kinase (JAK) inhibitor used primarily for the treatment of myelofibrosis, a rare bone marrow disorder characterized by excessive scar tissue formation that impairs blood cell production. By inhibiting JAK1, JAK2, and mutant JAK2 V617F signaling, the medication helps reduce symptoms such as anemia, enlarged spleen, and constitutional symptoms associated with this condition.
Momelotinib is a JAK inhibitor used to treat myelofibrosis by targeting abnormal JAK signaling pathways involved in the disease.
Key facts at a glance
- ATC
- L01EJ04
- RxNorm
- 2665204
- Generic
- Momelotinib
- Class
- atc-l01
- Brands
- Ojjaara
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet
- 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.
Momelotinib is approved for the treatment of intermediate-2 or high-risk myelofibrosis in adult patients, including those with primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocythemia myelofibrosis. It is particularly beneficial for patients experiencing anemia-related symptoms.
Momelotinib works by inhibiting JAK1 and JAK2 enzymes, including the mutant JAK2 V617F variant, which are involved in cytokine and growth factor signaling pathways that drive the abnormal blood cell production and inflammation seen in myelofibrosis. This inhibition helps reduce spleen enlargement and improve blood cell counts.
Common side effects may include thrombocytopenia, neutropenia, fatigue, and dizziness. Patients should be monitored for signs of infection due to immune system effects. Momelotinib may cause harm to an unborn baby and should not be used during pregnancy. Regular blood count monitoring is required during treatment.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
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