Treatment Options for Polycythemia Vera

A Brief Overview of Treatment of Polycythemia Vera

Medically reviewed by Doru Paul, MD

Polycythemia vera, a myeloproliferative neoplasm, results from a genetic mutation which leads to the production of too many red blood cells (erythrocytosis). The white blood cell and platelet counts may also be elevated. This increase in the number of blood cells (without an increase in the liquid portion of blood) increases the risk of clot development.

Learning you have been diagnosed with polycythemia vera can be distressing and naturally, you may wonder, "How can it be treated?" Fortunately, with treatment, survival increases from six to 18 months to 13 years or more. One of the challenges in treating polycythemia vera is that more than 12 percent of people will transform into myelofibrosis and around 7 percent will develop acute leukemia/myelodysplastic syndrome.

In contrast to most people with essential thrombocythemia, people with polycythemia vera commonly have symptoms like headache, dizziness, or itchiness at diagnosis. These symptoms are generally distressing and require the initiation of treatment.

Phlebotomy for PV

The primary treatment of polycythemia vera is therapeutic phlebotomy. In therapeutic phlebotomy, blood is removed from the body similar to a blood donation to reduce the number of red blood cells in circulation. Therapeutic phlebotomy is continued on a regular basis to keep the hematocrit (concentration of red blood cells) below 45%, though some healthcare providers will use different targets depending on gender (45% for men and 42% for women). Phlebotomy treats polycythemia vera in two ways: by decreasing the number of blood cells by physically removing them from the body and by causing an iron deficiency that limits new red blood cell production.

Hydroxyurea for PV

In people with a high risk of developing a blood clot (more than 60 years of age, history of blood clots), additional therapy is needed. Often the first medication added to therapeutic phlebotomy is oral hydroxyurea.

Takeaway

Low-dose aspirin (81– 100 mg/d) is recommended as a front-line therapy for:

• Patients with low-risk PV (those age 60 and under with no history of thrombosis). Phlebotomy is also recommended.

• Patients with high-risk PV (those over the age of 60 and/or a history of thrombosis). Both phlebotomy and cytoreductive therapy are also recommended.

Hydroxyurea is an oral chemotherapeutic agent that reduces the production of red blood cells in the bone marrow. It also reduces the production of white blood cells and platelets. Similar to other conditions treated with hydroxyurea, it is started at a low dose and increased until the hematocrit is in the goal range.

It is normally well tolerated with few side effects other than the decreased production of blood cells. Other side effects include oral ulcers, very sore throat, fatigue, weakness, bruising, wounds that won't heal, and more rarely there can be hyperpigmentation (dark discoloration of the skin), and nail changes (dark lines under nails).

Interferon Alpha for PV

For people who have PV symptoms such as unmanageable itching (called pruritus) and enlarged spleen, interferon-alpha may be used. It is usually reserved for younger, more physically fit patients, as well as women who are pregnant or in childbearing years, or refractory to prior therapies. Interferon-alpha is a subcutaneous injection that reduces the red blood cell count. It can also reduce spleen size and itching. Side effects include fever, weakness, nausea, and vomiting which limits the usefulness of this medication.

Busulfan for PV

For patients that have failed hydroxyurea and/or interferon-alpha, busulfan, a chemotherapeutic medication, may be used. The dose is changed to keep the white blood cell count and platelet count in an acceptable range.

However, Busulfan has fallen out of favor for the treatment of PV due to potential side effects that include low blood counts, pulmonary fibrosis, and hyperpigmentation.

Ruxolitinib for PV

Another medication used for patients that failed other therapies is ruxolitinib. This medication inhibits the JAK enzyme that is often affected in polycythemia vera and other myeloproliferative neoplasms. It is often used for people who develop post-polycythemia vera myelofibrosis. It can also be helpful in people with severe symptoms and splenomegaly (enlarged spleen) that causes significant pain or other issues.

Remember, although polycythemia vera is a chronic condition, it is manageable. Talk to your healthcare provider about the various treatment options available.