How it is administered

Ruxolitinib is available as oral tablets for systemic use and as a topical cream for skin conditions.

• Oral tablets: The tablets are taken by mouth, with or without food. The dose and frequency depend on the specific condition being treated and the patient's blood counts. For blood cancers, such as myelofibrosis, the starting dose is typically based on the patient's platelet count.

• Topical cream: The cream is applied directly to the skin for conditions like atopic dermatitis or vitiligo, not for blood cancers.

How it works

Ruxolitinib is a Janus kinase (JAK) inhibitor, specifically targeting JAK1 and JAK2 enzymes. These enzymes are involved in the signaling pathways of various cytokines and growth factors that are important for blood cell production (hematopoiesis) and immune function.

By inhibiting JAK1 and JAK2, ruxolitinib disrupts abnormal signaling that can lead to the excessive production of blood cells and inflammatory cytokines, which is common in certain blood cancers. This helps to reduce symptoms such as enlarged spleen and abnormal blood counts. In animal models, ruxolitinib has been shown to decrease the number of abnormal cells and reduce inflammation. Its effect on the immune system also makes it useful in conditions like graft-versus-host disease.

The medication is processed mainly by the liver and excreted through urine and feces. Its action is reversible, and blood levels peak within 1-2 hours after taking a dose.

Who Should take it

Ruxolitinib is approved for adults with certain blood cancers and immune-related conditions, including:

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

While ruxolitinib is not specifically approved for T-Cell Prolymphocytic Leukemia (T-PLL), it may be considered in some cases if other treatments are not effective, especially if the disease involves abnormal JAK-STAT signaling. Always consult with a hematologist or oncologist for personalized recommendations.

Who should not take it

There are no absolute contraindications listed for ruxolitinib, but certain patients should use caution or avoid it:

• Patients with active, serious infections should delay starting ruxolitinib until the infection is controlled.
• Those with very low platelet counts or severe anemia may not be able to tolerate the medication.
• People with a history of tuberculosis, hepatitis B, or herpes zoster should be evaluated and monitored closely.
• Pregnant or breastfeeding women should avoid ruxolitinib, as safety in these groups is not established.
• Patients with severe liver or kidney impairment may require dose adjustments or may not be suitable for treatment.

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

Commonly used with

Ruxolitinib may be used alongside other supportive treatments such as blood transfusions for anemia or antibiotics for infections. In the setting of graft-versus-host disease, it may be used with corticosteroids or other immunosuppressive medications.

It is important to inform your healthcare team of all medications you are taking, as ruxolitinib can interact with other drugs, especially those affecting liver enzymes (CYP3A4 inhibitors or inducers).

Commonly tested with

Ruxolitinib has been studied in combination with other therapies for blood cancers and GVHD, such as:

• Hydroxyurea (for polycythemia vera)
• Immunosuppressive agents (for GVHD)
• Supportive care medications (antibiotics, antivirals, antifungals)

Clinical trials may also test ruxolitinib with chemotherapy or other targeted agents in various blood cancers. Always follow your doctor's guidance regarding combination therapies.