How it is administered

Ruxolitinib is taken by mouth as a tablet. The tablets come in different strengths (5 mg, 10 mg, 15 mg, 20 mg, and 25 mg). The exact dose and frequency depend on your blood counts and the condition being treated. For blood cancers like myelofibrosis or polycythemia vera, it is usually taken twice daily. Ruxolitinib can be taken with or without food. If you miss a dose, take your next dose at the regular time; do not double up doses. For patients unable to swallow tablets, ruxolitinib can be given through a nasogastric tube as a suspension prepared from the tablet.

How it works

Ruxolitinib is a type of medicine called a kinase inhibitor. It works by blocking certain enzymes in the body known as Janus Associated Kinases (JAK1 and JAK2). These enzymes are important for the signaling of various growth factors and cytokines that help control blood cell production and immune system function.

In diseases like myelofibrosis, polycythemia vera, and post-essential thrombocythemia myelofibrosis, the JAK pathway is often overactive, leading to abnormal blood cell growth and symptoms like an enlarged spleen and fatigue. By blocking JAK1 and JAK2, ruxolitinib helps reduce the abnormal growth of blood cells, decrease inflammation, and improve symptoms such as spleen size and quality of life. It also helps control blood counts and reduce the need for procedures like phlebotomy in polycythemia vera.

Who Should take it

Ruxolitinib is used in adults with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. It is also used in adults with polycythemia vera who have not responded to or cannot tolerate hydroxyurea.

Additionally, ruxolitinib is used for certain types of graft-versus-host disease (GVHD) in adults and children 12 years and older. For essential thrombocythemia, ruxolitinib may be considered if the disease has progressed to myelofibrosis, but it is not a standard first-line treatment for essential thrombocythemia itself.

Who should not take it

There are no absolute contraindications listed for ruxolitinib, but it should not be started in people with active serious infections. Caution is needed in people with very low blood counts (especially platelets, red cells, or neutrophils), severe liver or kidney problems, or a history of tuberculosis or hepatitis B.

Women who are pregnant or breastfeeding should not take ruxolitinib, as its safety in pregnancy is not established. Children under 12 years old should not take it for most indications except certain types of GVHD. Always tell your doctor about all your health conditions and medications before starting ruxolitinib.

Commonly used with

Ruxolitinib may be used alone or with other supportive treatments such as blood transfusions, antibiotics for infections, or medications to manage side effects. In some cases, it may be used after or instead of other treatments like hydroxyurea for polycythemia vera or essential thrombocythemia that has progressed to myelofibrosis.

For graft-versus-host disease, ruxolitinib may be used with corticosteroids or other immunosuppressive therapies.

Commonly tested with

In clinical studies, ruxolitinib has been compared to best available therapy, which may include hydroxyurea, interferon, or corticosteroids, depending on the condition. It has also been tested in combination with other immunosuppressive drugs for graft-versus-host disease.

Your doctor may also order regular blood tests to monitor your blood counts and organ function while you are taking ruxolitinib.