A study of ruxolitinib for early myelofibrosis

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Blood cancers




Phase 3

This study is looking at a drug called ruxolitinib for myelofibrosis. It is for people who have certain high risk gene changes (mutations).

More about this trial

Myelofibrosis is a rare blood disorder. It is a condition that causes scarring of the bone marrow. You don’t usually have treatment for early myelofibrosis that isn’t causing symptoms. Instead you have regular check ups to see how you are getting on. 
Some myelofibrosis cells have faulty (mutated Open a glossary item) genes. Research suggests there are 5 genes possibly linked to developing more severe myelofibrosis. These are called these high risk mutations. 

Researchers are looking at ways of delaying or lowering the chances of early myelofibrosis becoming more severe in people at high risk. In this study, they are looking at ruxolitinib.

Ruxolitinib is type of biological therapy Open a glossary item called a cancer growth blocker. It stops signals that cancer cells use to divide and grow. 

It is already used to treat more severe myelofibrosis. Doctors aren’t sure how well it will work for early myelofibrosis but they want to find out more. 

Some people will have ruxolitinib and some won’t and have check ups as usual. 

The aims of the study are to:

  • find out if ruxolitinib is a useful treatment for high risk early myelofibrosis
  • find out if treatment affects quality of life
  • learn more about side effects

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study team if you are unsure about any of these. They will be able to advise you. 

You might be able to join this study if all of the following apply. 

  • You have myelofibrosis with mild (grade 1) scarring of the bone marrow
  • You have at least 1 gene change (mutation) in 1 of the 5 high risk gene changes
  • If your spleen Open a glossary item is enlarged it is less than 5cm from the bottom of the ribcage
  • Your myelofibrosis isn’t causing too many symptoms – symptoms might include tiredness, tummy (abdominal) pain and night sweats
  • Your recent blood test results show:
    • a platelet count of > 75000
    • a low number of immature blood cells (blasts)
    • your haemoglobin is more than 10
    • your white blood cell count is 15 or less
    • a type of white blood cell (a neutrophil Open a glossary item) is more than 1000
  • You have other satisfactory blood test results
  • You are well enough to be up and about for at least half the day (performance status 0,1 or 2)
  • You are willing to use reliable contraception during the study and for 1 month afterwards
  • You are at least 18 years old 

You cannot join this study if any of the following apply.

Cancer related

  • You have already had treatment with ruxolitinib or another type of drug that targets and stops the action of the JAK2 gene 
  • You have been deemed as suitable to have a stem cell transplant Open a glossary item

Medical conditions 

  • You have had any other cancer in the past 3 years apart from non melanoma skin cancer Open a glossary item that was successfully treated
  • You have had a rare viral disease of the brain called progressive multifocal leuko-encephalopathy (PML)
  • Your liver and kidneys aren’t working properly
  • You have problems with your heart, such as a heart attack in the last 6 months, high blood pressure that is not well controlled, angina that is not well controlled or an abnormal rhythm of your heart 
  • You have an infection that needs treatment 
  • You have a problem with your digestive system Open a glossary item that could affect how you absorb tablets
  • You have HIV
  • You have an active hepatitis A, hepatitis B or hepatitis C infection that needs treatment


  • You are sensitive to ruxolitinib or anything it contains
  • You take medication that affects body substances called CYP3A4 enzymes
  • You have had treatment with experimental drugs in the last 30 days
  • You have any other serious medical condition or mental health problem that the trial team think could affect you taking part
  • You are pregnant or breastfeeding

Trial design

This is a phase 3 study. The researchers need 320 people to take part worldwide including 15 from the UK.

It is a randomised study. You are put into 1 of 2 groups. 

  • One group have ruxolitinib
  • The other group have a dummy drug (placebo Open a glossary item)

Neither you nor your doctor will be able to decide which group you are in. And neither of you will know which group you are in either. This is called a double blind study.

study diagram

Ruxolitinib and the dummy drug are tablets. You have ruxolitinib or dummy tablets twice every day. You have treatment for as long as it is helping and the side effects aren’t too bad. 

If your spleen enlarges or you develop symptoms you might continue to have treatment. But you will probably have a different dose. The study team can tell you more if this applies. 

Research samples
You have extra blood tests as part of this study. Where possible you have these at the same time as your routine blood tests. The researchers want to find out what happens to ruxolitinib in the body (pharmacokinetics Open a glossary item) and to look for substances called biomarkers Open a glossary item to find out why treatment might work for some people and not for others.

Quality of life
The study team will ask you to fill out a questionnaire before you start treatment and at set times during treatment. The questionnaire asks about side effects and how you’ve been feeling. This is called a quality of life study.

Hospital visits

You see a doctor and have some tests before you can take part. These include:

You see the study team for a check up once a month. You have an MRI scan or CT scan every 3 months. 

Side effects

As ruxolitinib is a new treatment for early myelofibrosis, there might be some side effects we don’t know about yet. 

The most common side effects of ruxolitinib are:

  • a drop in blood cells causing an increased risk of infection, bleeding problems, tiredness and breathlessness
  • kidney or bladder infections
  • high levels of cholesterol in the blood
  • dizziness
  • headache
  • weight gain
  • high levels of liver enzymes

The study doctors will explain all the possible side effects before you join the study.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Tim Sommervaille

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Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Wendy took part in a new trial studying the possible side effect of hearing loss

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