Research and coping with essential thrombocythaemia (ET)

Essential thrombocythaemia (ET) is a rare blood cancer. It causes a high number of blood cells called platelets to form. These cells are involved in blood clotting. 

Research into essential thrombocythaemia

Researchers around the world are looking at better ways to treat essential thrombocythaemia and manage treatment side effects. Go to Cancer Research UK’s clinical trials database if you are looking for a trial for ET in the UK. Click on the ‘recruiting’, ‘closed’ and ‘results’ tabs to make sure you see all the trials.

As this is rare cancer there may not be an open trial. Do talk to your doctor or specialist nurse, they may know of trials available in the UK.

Some of the trials may have stopped recruiting people. It takes time before the results are available. This is because the trial team follow the patients for a period of time and collect and analyse the results. We include this ongoing research to give examples of the type of research being carried out.

Research and clinical trials

All cancer treatments must be fully researched before they can be used for everyone. This is so we can be sure that:

  • they work
  • they work better than the treatments already available
  • they are safe

Myeloproliferative neoplasms (MPN)

Essential thrombocythaemia is one of a group of conditions called myeloproliferative neoplasms (MPNs). They also include:

  • myelofibrosis

  • polycythaemia vera

Research into improving diagnosis

Gene changes

We already know from research that changes in the CALR, MPL and JAK2 gene changes are important in ET. Scientists continue to look at the changes inside ET cells and are learning more about other gene mutations Open a glossary item.

Researchers want to understand more about these genetic changes and why they might happen.

JAK2 gene

Researchers are looking at ways to improve the diagnosis and treatment of all MPNs. Some of this research is suggesting that it may be better to group these cancers depending on whether they are:

  • JAK2 positive or
  • JAK2 negative

The JAK2 gene makes a protein that controls how many blood cells the stem cells make. A fault with your JAK2 gene means the stem cells can start producing platelets when they're not meant to. Scientists hope that improving the diagnosis this way might help doctors choose targeted treatments in the future.

How do myeloproliferative neoplasms develop?

Doctors are looking to try to explain how MPNs develop. And to use this information to develop new treatments in the future. Scientists think that MPNs might happen because proteins called tyrosine kinases act as growth factors Open a glossary item and tell cells to keep on dividing. Researchers are looking at white blood cells in samples from people taking part in a study. They are looking for tyrosine kinases and for any features or damage which may make them keep on dividing.

Research into treatment

Researchers are looking into new types of treatment to stop the JAK2 gene signalling to stem cells to make more blood cells. These are called JAK2 inhibitors. Ruxolitinib is a JAK2 inhibitor. It works by slowing or stopping the growth of cancer cells. Researchers are looking at the results of a trial using ruxolitinib and a chemotherapy drug called azacitidine for people with ET.

Other drugs

Other drugs that are being looked at internationally include:

  • tamoxifen
  • pacritinib - a type of targeted cancer drug Open a glossary item called a cancer growth blocker Open a glossary item
  • INCB057643 - a  type of targeted drug

Other research

UK trial teams are also looking more closely at the relationship between ET and blood clots.

Cancer Research UK Clinical Trials Database

You can find a clinical trial looking at essential thrombocythaemia on our clinical trials database. 


Generally speaking, the outlook is good, if the condition is carefully monitored and treated as needed.

Some people with ET go on to develop a more aggressive disease. This might include progressing to myelofibrosis, where the bone marrow becomes scarred and less able to produce cells. Fewer than 6 in 100 people (fewer than 6%) go on to develop acute myeloid leukaemia (AML). 

Everyone is different, and your specialist will be able to give you a clearer idea of how things look in your situation.


Coping with a rare condition can be difficult both practically and emotionally. Being well informed about your condition and possible treatments can make it easier to make decisions and cope with what happens.

It can also help to talk to people with the same thing. But it can be hard to find someone with a rare condition. You can look at Cancer Research UK’s discussion forum - Cancer Chat. It is a place to share experiences, stories and information with other people who know what you are going through.

Cancer Research UK nurses

For support and information, you can call the Cancer Research UK information nurses. They can give advice about who can help you and what kind of support is available. Freephone: 0808 800 4040 - Monday to Friday, 9am to 5pm.


MPN Voice

MPN Voice provides information, community and advocacy for people with myeloproliferative neoplasms and their families or carers. They also have information for healthcare professionals.


Telephone: 07934 689 354 (Monday to Friday between 8am and 5pm)

Leukaemia Care

Leukaemia Care is a national blood cancer support charity, committed to ensuring that anyone affected by blood cancer receives the right information, advice and support. 

It provides a range of support services to patients and their carers, including information, support groups, patient and carer conferences, and nurse education days.

Freephone helpline: 08088 010 444 

Chat via WhatsApp on 07500068065

Blood Cancer UK

Blood Cancer UK funds research into leukaemia, lymphoma and myeloma. It also provides patient information booklets and leaflets that you can download or order from their website. 

Support line: 0808 2080 888 

Email address:

  • Cancer Research UK Clinical Trials Database

    Accessed November 2023 

  • website

    Accessed November 2023 

  • JAK2 inhibitors for myeloproliferative neoplasms: what is next?

    P Bose P and S Verstovsek

    Blood, 2017. Volume 130, Issue 2

  • Myeloproliferative Neoplasms

    National Comprehensive Cancer Network, 2020

  • Essential thrombocytosis

    BMJ Best Practice

    Accessed November 2023

Last reviewed: 
21 Nov 2023
Next review due: 
21 Nov 2026

Related links