How it is administered

Ruxolitinib is available in two main forms:

• Tablets for oral use: These are taken by mouth, usually twice daily, with or without food. The dose depends on the specific disease being treated and your blood counts.
• Topical cream: This is applied directly to the skin for certain non-cancer conditions (like atopic dermatitis or vitiligo), but not for blood cancers.

For blood cancers and related conditions, the oral tablet is the standard form. Your doctor will tell you exactly how much and how often to take it. If you have trouble swallowing tablets, ruxolitinib can also be given through a nasogastric tube as a liquid suspension.

How it works

Ruxolitinib is a type of medication called a Janus kinase (JAK) inhibitor. It works by blocking the activity of two enzymes, JAK1 and JAK2, which are important for the signaling of certain proteins (cytokines and growth factors) that help blood cells grow and function.

In some blood cancers, like myelofibrosis and polycythemia vera, these signals become overactive, causing abnormal blood cell growth and symptoms such as an enlarged spleen and fatigue. By inhibiting JAK1 and JAK2, ruxolitinib helps to reduce this abnormal signaling, which can decrease symptoms, reduce spleen size, and improve quality of life.

Ruxolitinib is also used in graft-versus-host disease (GVHD), a complication of stem cell transplant, where it helps by reducing inflammation and immune overactivity.

Who Should take it

Ruxolitinib is prescribed for adults with certain blood cancers and related conditions, including:

• Intermediate or high-risk myelofibrosis (including primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis)
• Polycythemia vera in adults who have not responded to or cannot tolerate hydroxyurea
• Steroid-refractory acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) in adults and children 12 years and older

Your doctor will determine if ruxolitinib is right for you based on your diagnosis, blood counts, and previous treatments.

Who should not take it

There are no absolute contraindications listed for ruxolitinib, but it should be used with caution in certain situations:

• If you have an active, serious infection, treatment should be delayed until the infection is controlled.
• People with very low blood counts (especially platelets or neutrophils) may not be able to start ruxolitinib until their counts improve.
• It should be used carefully in people with a history of tuberculosis, hepatitis B, or herpes infections.
• Pregnant or breastfeeding women should avoid ruxolitinib, as its safety in these groups is not established.

Always discuss your full medical history with your doctor before starting ruxolitinib.

Commonly used with

Ruxolitinib is sometimes used alongside other medications, depending on your condition:

• In graft-versus-host disease, it may be used with corticosteroids or other immunosuppressive drugs.
• In myelofibrosis or polycythemia vera, it may be used after or instead of other treatments like hydroxyurea.

Always tell your doctor about all medications and supplements you are taking, as ruxolitinib can interact with certain drugs (like strong CYP3A4 inhibitors or inducers).

Commonly tested with

Ruxolitinib has been tested in combination with:

• Hydroxyurea (in polycythemia vera)
• Various immunosuppressive agents (in graft-versus-host disease)
• Best available therapy regimens (in clinical trials for myelofibrosis and polycythemia vera)

It is important not to combine ruxolitinib with other JAK inhibitors or potent immunosuppressants unless directed by your doctor.