What is myelofibrosis?

Learn about myelofibrosis and some of its symptoms.
Not actual patient.

Myelofibrosis is a rare blood cancer that affects the blood and bone marrow

 

Myelofibrosis (my-ah-lo-fye-BRO-sis; MF) is one part of a bigger group of blood cancers called myeloproliferative neoplasms, or MPNs. In people with myelofibrosis, the spongy tissues inside the bones (the bone marrow) develop inflammation and scarring. This is called bone marrow fibrosis, which interferes with the production of healthy blood cells.

About 25,000 people in the United States are living with myelofibrosis. Each person experiences myelofibrosis in their own way. For instance, some people may develop anemia.

It was a couple of years after my diagnosis that my spleen started to swell. I found an oncologist that has been wonderful, calm, and reassuring. They keep me in the loop so I can be an active participant in my care.

Real patient, compensated by GSK.

Anemia in myelofibrosis

About 60% of people are anemic within 1 year of their myelofibrosis diagnosis

About 60% of people are anemic within 1 year of their myelofibrosis diagnosis

46% of patients need blood transfusions within 1 year of their myelofibrosis diagnosis

and 46% need blood transfusions

Anemia means you have a low red blood cell count. Your healthcare provider may call this low hemoglobin. When you have anemia, you may feel tired, weak, or short of breath.

 

There are other symptoms of myelofibrosis that you may also experience:

Enlarged spleen

The spleen works like a filter for your blood. Having myelofibrosis can cause your spleen to get too big. This is called splenomegaly, and it may make you feel full too quickly or have pain under your left rib.

Low platelet count

Platelets are a type of blood cell that help your blood clot. When your body doesn’t make enough platelets, it’s called thrombocytopenia. This can cause problems like bleeding or bruising easily. 

Other myelofibrosis symptoms

Myelofibrosis can cause other symptoms throughout the body. Other symptoms of myelofibrosis may include night sweats, pain under the left rib, weight loss, fatigue, tiredness, abdominal pain, itching, or bone pain.

Get news, resources, and updates about OJJAARA

Sign up today

You'll receive access to information and resources about OJJAARA that may support you on your journey.

Caring for a loved one who has myelofibrosis with anemia?

Find resources for caregivers and their loved ones.

How OJJAARA works

Learn how OJJAARA works to treat myelofibrosis with anemia.

APPROVED USE & SAFETY INFO

APPROVED USE

IMPORTANT SAFETY INFORMATION

APPROVED USE

OJJAARA is a prescription medicine used to treat adults with certain types of myelofibrosis (MF) who have anemia. It is not known if OJJAARA is safe and effective in children.

IMPORTANT SAFETY INFORMATION

OJJAARA may cause serious side effects, including:

  • Risk of Infections. People who take OJJAARA may develop serious infections that can lead to death, such as bacterial and viral infections, including COVID-19. If you have an active infection, your healthcare provider should not start treatment with OJJAARA until your infection is gone. If you have had hepatitis B for a long time (chronic), OJJAARA may cause your hepatitis B to become active again, and your healthcare provider will check your blood for active hepatitis B before starting treatment. Your healthcare provider will monitor you and treat you for any infections that you get during treatment with OJJAARA. Tell your healthcare provider right away if you develop any of the following symptoms of infection:
    • fever
    • chills
    • cough
    • breathing problems
    • diarrhea
    • vomiting
    • pain or burning feeling when passing urine

  • Low platelet and white blood cell counts. OJJAARA may cause new or worsening low platelet and white blood cell counts. Low platelet counts may increase your risk for bleeding and low white blood cell counts may increase your risk for infection. Your healthcare provider will do blood tests to check your blood counts before you start taking OJJAARA and during treatment. Tell your healthcare provider right away if you have any signs of bleeding during treatment with OJJAARA, including:
    • unusual bleeding
    • black or tarry stools
    • bruising

  • Liver problems. OJJAARA may cause new or worsening increased liver enzymes and bilirubin in your blood. Your healthcare provider will check your liver enzymes before starting treatment, every month for the first 6 months of treatment, and then as needed during treatment with OJJAARA. Your healthcare provider may stop treatment with OJJAARA if your liver enzymes increase. Tell your healthcare provider if you develop any of the following signs or symptoms of liver problems:
    • tiredness
    • loss of appetite
    • pain in your right upper stomach area (abdomen)
    • dark urine
    • yellowing of your skin or the white part of your eyes

  • Major cardiovascular events such as heart attack, stroke, and death. Major cardiac events have happened, especially in people with cardiac risk factors and who are current or past smokers, taking another Janus kinase (JAK) inhibitor to treat rheumatoid arthritis. OJJAARA is in the JAK family of medicines. Get emergency help right away if you have any symptoms of a heart attack or stroke while taking OJJAARA, including:
    • discomfort in your chest that lasts for more than a few minutes, or that goes away and comes back
    • severe tightness, pain, pressure, or heaviness in your chest, throat, neck, or jaw
    • pain or discomfort in your arms, back, neck, jaw, or stomach
    • shortness of breath with or without chest discomfort
    • breaking out in a cold sweat
    • nausea or vomiting
    • feeling lightheaded
    • weakness in one part or on one side of your body
    • slurred speech

  • Blood clots. Blood clots in the veins of the legs (deep vein thrombosis, DVT) or lungs (pulmonary embolism, PE) have happened in some people taking another JAK inhibitor to treat rheumatoid arthritis, and may be life-threatening. Tell your healthcare provider if you have had blood clots in the veins of your legs or lungs in the past. Tell your healthcare provider right away if you have any signs and symptoms of blood clots during treatment with OJJAARA, including:
    • swelling, pain, or tenderness in one or both legs
    • sudden, unexplained chest pain
    • shortness of breath or difficulty breathing

  • New cancers. New cancers, including lymphoma and other cancers, except non-melanoma skin cancer, have happened in some people taking another JAK inhibitor to treat rheumatoid arthritis. The risk of new cancers is further increased in people who smoke or who smoked in the past.

 

The most common side effects of OJJAARA include:

  • low platelet count
  • bleeding
  • bacterial infection
  • tiredness
  • dizziness
  • diarrhea
  • nausea

 

These are not all the possible side effects of OJJAARA. Call your doctor for medical advice about side effects.

 

Before taking OJJAARA, tell your healthcare provider about all your medical conditions, including if you:

  • have an infection
  • have or have had hepatitis B
  • have or have had liver problems
  • have had a heart attack, or have or have had other heart problems, or stroke
  • have or have had a blood clot
  • smoke or were a smoker in the past
  • have or have had any other cancers
  • are pregnant or plan to become pregnant. OJJAARA may harm your unborn baby.
    Females who are able to become pregnant:
    • You should use effective birth control (contraception) during treatment and for 1 week after the last dose of OJJAARA.
    • Tell your healthcare provider right away if you think you are pregnant or become pregnant during treatment with OJJAARA.
  • are breastfeeding or plan to breastfeed. It is not known if OJJAARA passes into your breast milk. You should not breastfeed during treatment and for 1 week after the last dose of OJJAARA. Talk to your healthcare provider about the best way to feed your baby during this time.

 

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking OJJAARA with certain other medicines may affect the amount of OJJAARA or the other medicines in your blood and may increase your risk of side effects.

 

Please see full Prescribing Information, including Patient Information for patients.

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 negative side effects to GSK at gsk.public.reportum.com or 1-888-825-5249.
GSK Help Center logo

Explore the GSK Help Center website to find customer service support and contact information.

Together with GSK Oncology logo

If you don’t have prescription coverage or need help paying for your medicines, call us at 1-844-4GSK-ONC (1-844-447-5662).