About Myelofibrosis (MF)

What is myelofibrosis?

Myelofibrosis, or MF, is a rare disease of the bone marrow. The bone marrow is the material inside the bone where blood cells are made. People with MF typically have:

  • Scarring in the bone marrow called fibrosis  (fye-BRO-sis)
  • Too few or too many cells that make blood
  • Symptoms such as itching, night sweats, bone and muscle pain, abdominal discomfort, early feeling of fullness, and pain under the left ribs

Bone marrow is where blood cells are made. As scar tissue builds up, the bone marrow can’t make enough blood cells. The spleen, which is an organ near the stomach under the left ribs, partially takes over making blood cells. This may make the spleen get bigger, a condition called splenomegaly (splee-nuh-MEG-uh-lee).

Breaking down

Myelofibrosis

myelo  means "bone marrow"

fibrosis  means "scarring"

Who gets myelofibrosis?

  • About 16,000 to 18,500 people in the United States have myelofibrosis (MF)
  • People are usually around 65 years old when they learn they have MF

What are the stages of myelofibrosis?

It's important to understand how myelofibrosis (MF) can affect your body over time. In its very early stages, the disease may be silent. You might not experience symptoms even though the disease may be progressing. As the disease gets worse, its signs and symptoms start to increase.

There are many things that can affect the course—or progression—of your MF. Researchers evaluate patients based upon these risk factors. It is estimated that 80% of people diagnosed with MF have intermediate or high-risk MF.

What causes myelofibrosis?

No one knows for sure what causes myelofibrosis (MF). We do know that certain proteins called Janus-associated kinases, or JAKs, are important. JAKs tell blood cells in the bone marrow to divide and grow.

When JAKs are working normally, they help the body make the right number of blood cells. But when JAKs aren’t working normally, they cause the body to make the wrong number of blood cells. They can also cause bone marrow scarring, an enlarged spleen, and symptoms.

Mutations, or changes, in genes are thought to be ultimately responsible for MF. The mutations may be in the genes that make JAKs, or the mutations may be in genes that affect how JAKs function. In either case, the mutations cause what is known as overactive JAK signaling.

MF can develop from other myeloproliferative neoplasms

MF is a chronic bone marrow condition that is part of a group of diseases called myeloproliferative neoplasms (MY-ah-lo-pro-LIF-er-uh-tiv NEE-o-plaz-uhms), or MPNs. If MF is a person’s first MPN, then it is called “primary myelofibrosis.”

In other cases, another MPN, like polycythemia vera (PV) or essential thrombocythemia (ET), can turn into MF. These conditions are called post–PV MF and post–ET MF. About 20% of MF patients have these conditions.

What are the symptoms of myelofibrosis?

Symptoms of myelofibrosis (MF) can range from mild to severe. They may be caused by an enlarged spleen or by production of too many cytokines, proteins that cause inflammation.

Spleen-Related Symptoms

As we discussed previously, if your bone marrow is not making enough blood cells (or making them too quickly so that they don’t have time to fully form), your spleen can take over and begin to make blood cells. This may make your spleen get bigger.

Symptoms of an enlarged spleen include:

  • Abdominal discomfort
  • Pain under the left ribs
  • Early feeling of fullness

Breaking down

Splenomegaly

spleno  means "of the spleen"

megaly  means "bigger than normal"

Approximately 85% or more of people with MF have an enlarged spleen at diagnosis.

Symptoms Not Related to the Spleen

Symptoms caused by overproduction of cytokines in the body include:

  • Itching
  • Night sweats
  • Bone and muscle pain

Approximately 50% to 60% of people with MF report having these types of non-spleen symptoms.

How are myelofibrosis symptoms tracked?

The symptoms that one person has with myelofibrosis (MF)—and how severe those symptoms are—may be different from your own. Keep track of those symptoms that affect you day to day. One way to keep careful track of the symptoms over time is to use a symptom diary. At each visit, report any new symptoms to your Healthcare Professional as well as any current symptoms that are getting worse.

An important goal of MF treatment is to reduce your symptoms. People living with MF may get used to their symptoms, and Healthcare Professionals may not realize how symptoms affect their patients. Talking with your Healthcare Professional about your symptoms is important. Your Healthcare Professional needs to know how you feel so that he or she can properly treat your condition.

How is myelofibrosis treated?

Myelofibrosis (MF) is a life-changing disease. Stay strong and keep a positive attitude. It’s important to learn all you can about MF and treatment options.

Your Healthcare Professional will work with you to make a plan that is right for you. One option is a medicine called Jakafi® (ruxolitinib). It is the only medicine approved by the Food and Drug Administration (FDA) to treat intermediate or high-risk MF. To learn more about how Jakafi works, click here.

To view stories from patients like you who have taken Jakafi, click here.



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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.