About Polycythemia Vera (PV)

What is polycythemia vera?

Polycythemia vera, or PV, is a rare, chronic, progressive blood cancer in which a person’s body makes too many red blood cells, white blood cells, and platelets. PV is part of a group of diseases called "myeloproliferative neoplasms," or MPNs.

Too many red blood cells can cause the blood to thicken. Thicker blood doesn’t flow normally through arteries and veins.

Who gets polycythemia vera?

Although polycythemia vera (PV) can occur in persons of any age, it is more common later in life. The average age when a person is diagnosed with PV is 60 years. PV affects slightly more men than women.

100kMap

About 100,000 people in the United States live with polycythemia vera.

What are the effects of polycythemia vera over time?

Polycythemia vera (PV) can be managed. Treatments are available that may help people keep their blood counts under control. However, PV is a chronic, progressive disease. That means it doesn’t go away and is likely to get worse over time.

In a very small number of people, PV leads to other blood diseases, such as myelofibrosis (a disease in which scar tissue develops in the bone marrow) or leukemia.

What causes polycythemia vera?

No one knows exactly what causes polycythemia vera (PV). Evidence suggests that proteins known as Janus kinases, or JAKs, are involved. JAK proteins send signals that affect the production of blood cells in the bone marrow. When JAKs send too many signals, they cause the bone marrow to make too many blood cells. This is called overactive signaling. Overactive JAK signaling is a key contributor to the development of PV.

Scientists think that overactive JAK signaling may be related to changes in the genes that make JAK proteins. These changes are called mutations. Almost everyone with PV has a mutation of the Janus kinase 2 (JAK2) gene. Even if you don’t have the JAK2 mutation, you still can have PV.

In addition to making too many blood cells, overactive JAK signaling may result in the overproduction of certain proteins called cytokines (SIGH-toe-kines) in people with PV. Cytokines can cause inflammation. When your body has too many of these proteins, you may experience various symptoms related to PV.

Your Healthcare Professional may do a blood test to see if you have a mutation, or change, in a gene that may cause PV.

What happens in the body as a result of polycythemia vera?

Polycythemia vera (PV) affects each person differently. Some patients with PV have an enlarged spleen. Your spleen helps your body fight infection and filter unwanted material, such as old or damaged blood cells. The increased number of blood cells caused by PV makes your spleen work harder than normal. This may cause the spleen to get bigger.

Some people with PV have no symptoms. In others, PV symptoms can be more severe. It is important to tell your Healthcare Professional about any symptoms you have, even if you are not sure they are related to your PV. Talking to your Healthcare Professional about your symptoms helps you both:

  • Understand how PV is affecting you
  • Follow how your PV is changing over time

Keeping your blood counts under control is important

Hematocrit is a measure of how much space red blood cells take up in your blood. Keeping hematocrit at the right levels—regularly below 45%—is an important goal in managing your PV. Your Healthcare Professional may have a different hematocrit target for you based on your individual case.

What are some treatments for polycythemia vera?

  • Low-dose aspirin and phlebotomy

Low-dose aspirin therapy is often the first treatment for patients with PV. It may be combined with phlebotomy. Phlebotomy is a procedure in which your blood cell counts are lowered by removing blood from your body.

  • Hydroxyurea, or HU, a chemotherapy drug

Patients with PV who have difficulty with phlebotomy, who have an enlarged spleen, or who have elevated blood counts may be prescribed HU. HU is a chemotherapy drug that reduces the number of blood cells, including red blood cells (RBCs), white blood cells (WBCs), and platelets.

1in4

PV may be considered uncontrolled in some patients who have already taken hydroxyurea. In one clinical study, it was shown that approximately 1 in 4 patients with PV do not benefit from HU treatment.

When HU is not working to control PV or is not being tolerated, patients may experience any of the following:

  • The need for phlebotomy in addition to HU to keep hematocrit levels below 45%
  • Other blood cell counts (WBCs and platelets) that are higher than they should be
  • Increasing disease-related signs or symptoms (eg, enlarged spleen)
  • Unacceptable side effects from HU
  • Jakafi® (ruxolitinib)

Another option to treat PV is a medicine called Jakafi. It is the first and only FDA-approved treatment for people with PV who have already taken a medicine called hydroxyurea and it did not work well enough or they could not tolerate it.

At your next appointment, ask about your current hematocrit level and whether your PV is under control. If your Healthcare Professional is having trouble keeping your hematocrit in your target range using HU, it may be a sign of resistance to HU.

If you have PV and did not benefit from or cannot tolerate HU, talk with your Healthcare Professional about whether or not Jakafi might be right for you. To learn how Jakafi works, click here.



Share this page:

Expand +

Indications and Usage

Jakafi is a prescription medicine used to treat people with polycythemia vera who have already taken a medicine called hydroxyurea and it did not work well enough or they could not tolerate it.

Jakafi is also used to treat certain types of myelofibrosis.

Important Safety Information

Jakafi can cause serious side effects, including:

Low blood counts: Jakafi® (ruxolitinib) may cause your platelet, red blood cell, or white blood cell counts to be lowered. If you develop bleeding, stop taking Jakafi and call your healthcare provider. Your healthcare provider will perform blood tests to check your blood counts before you start Jakafi and regularly during your treatment. Your healthcare provider may change your dose of Jakafi or stop your treatment based on the results of your blood tests. Tell your healthcare provider right away if you develop or have worsening symptoms such as unusual bleeding, bruising, tiredness, shortness of breath, or a fever.

Infection: You may be at risk for developing a serious infection during treatment with Jakafi. Tell your healthcare provider if you develop any of the following symptoms of infection: chills, nausea, vomiting, aches, weakness, fever, painful skin rash or blisters.

Skin cancers: Some people who take Jakafi have developed certain types of non-melanoma skin cancers. Tell your healthcare provider if you develop any new or changing skin lesions.

Increases in cholesterol: You may have changes in your blood cholesterol levels. Your healthcare provider will do blood tests to check your cholesterol levels during your treatment with Jakafi.

The most common side effects of Jakafi include: low platelet count, low red blood cell counts, bruising, dizziness, headache.

These are not all the possible side effects of Jakafi. Ask your pharmacist or healthcare provider for more information. Tell your healthcare provider about any side effect that bothers you or that does not go away.

Before taking Jakafi, tell your healthcare provider about: all the medications, vitamins, and herbal supplements you are taking and all your medical conditions, including if you have an infection, have or had tuberculosis (TB) or have been in close contact with someone who has TB, have or had hepatitis B, have or had liver or kidney problems, are on dialysis, had skin cancer, or have any other medical condition. Take Jakafi exactly as your healthcare provider tells you. Do not change your dose or stop taking Jakafi without first talking to your healthcare provider. Do not drink grapefruit juice while on Jakafi.

Women should not take Jakafi while pregnant or planning to become pregnant, or if breast-feeding.

Please see the Full Prescribing Information, which includes a more complete discussion of the risks associated with Jakafi.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

You may also report side effects to Incyte Medical Information at 1-855-463-3463.
 
IMPORTANT SAFETY INFORMATION
 
INDICATIONS AND USAGE

Jakafi is a prescription medicine used to treat people with polycythemia vera who have already taken a medicine called hydroxyurea and it did not work well enough or they could not tolerate it.

Jakafi is also used to treat certain types of myelofibrosis.

IMPORTANT SAFETY INFORMATION

Jakafi can cause serious side effects, including:

Low blood counts: Jakafi® (ruxolitinib) may cause your platelet, red blood cell, or white blood cell counts to be lowered. If you develop bleeding, stop taking Jakafi and call your healthcare provider. Your healthcare provider will perform blood tests to check your blood counts before you start Jakafi and regularly during your treatment. Your healthcare provider may change your dose of Jakafi or stop your treatment based on the results of your blood tests. Tell your healthcare provider right away if you develop or have worsening symptoms such as unusual bleeding, bruising, tiredness, shortness of breath, or a fever.

Infection: You may be at risk for developing a serious infection during treatment with Jakafi. Tell your healthcare provider if you develop any of the following symptoms of infection: chills, nausea, vomiting, aches, weakness, fever, painful skin rash or blisters.

Skin cancers: Some people who take Jakafi have developed certain types of non-melanoma skin cancers. Tell your healthcare provider if you develop any new or changing skin lesions.

Increases in cholesterol: You may have changes in your blood cholesterol levels. Your healthcare provider will do blood tests to check your cholesterol levels during your treatment with Jakafi.

The most common side effects of Jakafi include: low platelet count, low red blood cell counts, bruising, dizziness, headache.

These are not all the possible side effects of Jakafi. Ask your pharmacist or healthcare provider for more information. Tell your healthcare provider about any side effect that bothers you or that does not go away.

Before taking Jakafi, tell your healthcare provider about: all the medications, vitamins, and herbal supplements you are taking and all your medical conditions, including if you have an infection, have or had tuberculosis (TB) or have been in close contact with someone who has TB, have or had hepatitis B, have or had liver or kidney problems, are on dialysis, had skin cancer, or have any other medical condition. Take Jakafi exactly as your healthcare provider tells you. Do not change your dose or stop taking Jakafi without first talking to your healthcare provider. Do not drink grapefruit juice while on Jakafi.

Women should not take Jakafi while pregnant or planning to become pregnant, or if breast-feeding.

Please see the Full Prescribing Information, which includes a more complete discussion of the risks associated with Jakafi.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

You may also report side effects to Incyte Medical Information at 1-855-463-3463.

INDICATIONS AND USAGE

Jakafi is a prescription medicine used to treat people with polycythemia vera who have already taken a medicine called hydroxyurea and it did not work well enough or they could not tolerate it.

Jakafi is also used to treat certain types of myelofibrosis.

IMPORTANT SAFETY INFORMATION

Jakafi can cause serious side effects, including:

Low blood counts: Jakafi® (ruxolitinib) may cause your platelet, red blood cell, or white blood cell counts to be lowered. If you develop bleeding, stop taking Jakafi and call your healthcare provider. Your healthcare provider will perform blood tests to check your blood counts before you start Jakafi and regularly during your treatment. Your healthcare provider may change your dose of Jakafi or stop your treatment based on the results of your blood tests. Tell your healthcare provider right away if you develop or have worsening symptoms such as unusual bleeding, bruising, tiredness, shortness of breath, or a fever.

Infection: You may be at risk for developing a serious infection during treatment with Jakafi. Tell your healthcare provider if you develop any of the following symptoms of infection: chills, nausea, vomiting, aches, weakness, fever, painful skin rash or blisters.

Skin cancers: Some people who take Jakafi have developed certain types of non-melanoma skin cancers. Tell your healthcare provider if you develop any new or changing skin lesions.

Increases in cholesterol: You may have changes in your blood cholesterol levels. Your healthcare provider will do blood tests to check your cholesterol levels during your treatment with Jakafi.

The most common side effects of Jakafi include: low platelet count, low red blood cell counts, bruising, dizziness, headache.

These are not all the possible side effects of Jakafi. Ask your pharmacist or healthcare provider for more information. Tell your healthcare provider about any side effect that bothers you or that does not go away.

Before taking Jakafi, tell your healthcare provider about: all the medications, vitamins, and herbal supplements you are taking and all your medical conditions, including if you have an infection, have or had tuberculosis (TB) or have been in close contact with someone who has TB, have or had hepatitis B, have or had liver or kidney problems, are on dialysis, had skin cancer, or have any other medical condition. Take Jakafi exactly as your healthcare provider tells you. Do not change your dose or stop taking Jakafi without first talking to your healthcare provider. Do not drink grapefruit juice while on Jakafi.

Women should not take Jakafi while pregnant or planning to become pregnant, or if breast-feeding.

Please see the Full Prescribing Information, which includes a more complete discussion of the risks associated with Jakafi.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

You may also report side effects to Incyte Medical Information at 1-855-463-3463.