A telomerase inhibitor for anaemia in lower-risk myelodysplastic syndromes
Imetelstat
A specialist medicine used to treat transfusion-dependent anaemia in certain adults with lower-risk myelodysplastic syndromes.
What is Imetelstat?
Imetelstat is a specialist medicine used to treat anaemia (a low level of healthy red blood cells) in certain adults with lower-risk myelodysplastic syndromes who need regular blood transfusions. Myelodysplastic syndromes are bone-marrow disorders in which blood cells are not made properly. Imetelstat works by blocking an enzyme called telomerase that the abnormal cells rely on, which can help the bone marrow make better red blood cells and reduce the need for transfusions. It is given by a hospital team. The main risks are severe drops in platelets and white cells, which can cause bleeding or infection, and infusion reactions, so it is closely monitored.
Education and reference only. This is a plain-language guide to Imetelstat — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Imetelstat is a specialist medicine used to treat the anaemia that occurs in lower-risk myelodysplastic syndromes, a group of bone-marrow disorders in which the marrow does not make enough healthy blood cells. It is used in certain adults whose anaemia is severe enough that they depend on regular blood transfusions and where other treatments have not worked or are not suitable. It is given as an infusion into a vein by a specialist haematology team. By targeting the abnormal cells in the marrow, it aims to improve red-blood-cell production so that fewer transfusions are needed.
How it works
In myelodysplastic syndromes, abnormal cells in the bone marrow crowd out and disrupt the normal production of healthy blood cells, leading to anaemia. Many of these abnormal cells rely on an enzyme called telomerase, which helps cells keep dividing. Imetelstat blocks telomerase, which can reduce the abnormal cells and allow the marrow to recover some of its ability to make healthy red blood cells. This can lessen or remove the need for blood transfusions in people who respond. Because it also affects the marrow more broadly, it can lower other blood cells too, which is why blood counts are watched closely.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist medicine used in the UK to treat anaemia in certain adults with lower-risk myelodysplastic syndromes who depend on blood transfusions.
Practical use
How to take Imetelstat
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by a hospital haematology team, as an infusion into a vein, on a schedule they arrange.
- Attend all your appointments and blood tests, as your blood counts guide whether and when the next dose is given.
- Report any unusual bruising, bleeding, fever, sore throat or other signs of infection to your team straight away.
- Tell the team if you feel unwell during or shortly after the infusion, as reactions can occur.
- Tell your team about all your medicines, as your overall treatment and transfusion plan are managed together.
Weighing it up
Advantages & disadvantages of Imetelstat
Advantages
- Can reduce or remove the need for blood transfusions in people who respond.
- Offers a treatment option for transfusion-dependent anaemia in lower-risk myelodysplastic syndromes when other options have not worked.
- Targets the abnormal cells in the bone marrow to help restore red-blood-cell production.
Disadvantages
- Can cause severe drops in platelets and white cells, raising the risk of bleeding and infection.
- Can cause reactions during or shortly after the infusion.
- A specialist hospital treatment that needs frequent blood tests and close monitoring.
Practical use
Good to know
The most important thing to understand is that imetelstat can cause severe drops in two key blood cells: platelets, which help blood to clot, and neutrophils, a type of white cell that fights infection. Low platelets can lead to easy bruising or bleeding, and low neutrophils raise the risk of infection, so blood counts are checked regularly and any unusual bruising, bleeding, fever or signs of infection should be reported promptly. Reactions during or shortly after the infusion can also happen, which is why it is given by a hospital team who watch you. It is a specialist haematology treatment for a specific situation, transfusion-dependent anaemia in lower-risk myelodysplastic syndromes, and the team carefully balances its benefits in reducing transfusions against these risks, adjusting treatment based on your blood counts.
Who should not take it / use with caution
- People who have had a serious allergic reaction to imetelstat should not receive it.
- It is used with particular care, or delayed, in people whose blood counts are already very low.
- It should only be used under specialist haematology supervision, with regular blood-count monitoring.
Monitoring
- Regular blood-count checks, particularly platelets and neutrophils, to guide treatment.
- Watching for signs of bleeding or infection between doses.
- Checking liver blood tests and how well the anaemia and transfusion need are responding.
Side effects
- Severe drops in platelets, causing easy bruising or bleeding.
- Severe drops in neutrophils (a type of white cell), raising the risk of infection.
- Tiredness, headache or reactions during or shortly after the infusion; less commonly, changes in liver blood tests.
Key interactions
- Other medicines that lower blood cells or increase bleeding risk are used with care alongside it, so tell your team about them.
- Your overall treatment, including any blood-thinning medicines, is reviewed because of the risk of low platelets.
- Tell your team about all your medicines, as treatment is balanced against your blood counts.
Available as: A solution given as an infusion into a vein by a specialist team.
Answers
Imetelstat: frequently asked questions
What is imetelstat used for?
It is used to treat anaemia in certain adults with lower-risk myelodysplastic syndromes who depend on regular blood transfusions, aiming to improve red-blood-cell production and reduce the need for transfusions.
Why are my blood counts checked so often?
Imetelstat can cause severe drops in platelets and white cells, which raise the risk of bleeding and infection, so blood counts are checked regularly to guide treatment safely.
What should I report between doses?
Report any unusual bruising or bleeding, or any fever, sore throat or other signs of infection, to your team straight away, as these can reflect low blood cells.
How is it given?
It is given by a hospital haematology team as an infusion into a vein, on a schedule guided by your blood counts.
Can it stop my transfusions?
In people who respond, it can reduce or remove the need for blood transfusions, but this varies between individuals and is reviewed by your team.
Authoritative sources
- BNF
- NICE CKS
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