A trial looking at a treatment to improve immunity after a stem cell transplant for blood cancers (ICAT)

Cancer type:

Acute leukaemia
Acute lymphoblastic leukaemia (ALL)
Acute myeloid leukaemia (AML)
Blood cancers
Chronic leukaemia
Chronic lymphocytic leukaemia (CLL)
Chronic myeloid leukaemia (CML)
Hodgkin lymphoma
Myelodysplastic syndrome (MDS)
Non-Hodgkin lymphoma




Phase 2

This trial looked at a treatment to help the immune system Open a glossary item to start working again after having a stem cell transplant from an unrelated donor. This is an allogeneic stem cell transplant.

It was for people with one of the following cancers:

This trial was open for people to join between 2014 and 2019. The team published the results in 2022.

More about this trial

Doctors can treat these cancers with chemotherapy followed by a stem cell transplant using cells from a donor . After a stem cell transplant your immune system won’t work properly for several months.

Before having your transplant the immune cells called T cells Open a glossary item are removed from the donor’s cells. This helps to stop their T cells attacking your body tissues. But sometimes it doesn’t work and it causes the condition graft versus host disease (GvHD). GvHD can affect the skin, digestive system Open a glossary item and other body organs. 

Removing most of the immune cells from the donor’s cells reduces the risk of GvHD. But it also affects other immune cells that help you fight infection.

The researchers looked at giving T cells from the donor to help fight infection. This was after they removed the cells that cause GvHD. These are allodepleted donor T cells (ADTs). 

Doctors use a similar method to treat children having an allogenic stem cell transplant.

Researchers wanted to see if it helped adults having a transplant using cells from an unrelated donor.

The aim of the trial was to see if having allodepleted T cells helps the immune system to recover more quickly without increasing the risk of GvHD.

Summary of results

The team found that ADTs are safe for people having an unrelated donor transplant. They found that their use in helping fight infection was limited. 

Trial design
This was a phase 2 trial Open a glossary item. 37 people took part in the trial.

It was a randomised trial Open a glossary item. Neither the person nor their doctor chose which group they went into. The 2 groups were:

  • 27 people had ADTs to improve their immunity Open a glossary item after their transplant
  • 10 people had the standard treatment Open a glossary item to prevent GvHD after their transplant

Of the 37 people, 16 people did not continue in the trial. This was due to a number of reasons including:

  • some donors refused to take part in the trial
  • people developed moderate to severe GvHD very soon after their transplant. This is acute GvHD
  • one person not wanting to continue in the trial (withdrawing consent)

Of the 21 people left:

  • 13 had ADTs
  • 8 had the standard treatment

4 months after the transplant the team took blood samples. They looked at how many T cells were in these samples. They found that there were more T cells in the blood of the people in the ADTs group than in the standard treatment. And that for 3 people who had ADTs their T cells were at the normal level. 

GvHD can be acute or chronic. Acute GvHD develops within 100 days of having the transplant. Chronic GvHD develops after 100 days of having the transplant. 

The team looked at the number of people in each group who developed moderate to severe acute GvHD. They found that the number of people who developed acute GvHD was:

  • 7 people in the ADTs group 
  • 4 people in the standard treatment group 

They also looked at the number of people in each group that developed chronic GvHD. They found that:

  • 3 people in the ADTs group developed it. Of these one had mild GvHD, one moderate and one was severe.
  • 3 people in the standard treatment group developed chronic GvHD. They were all mild.  

The team concluded that there might be several reasons as to why ADTs didn’t help.

They thought one reason could be the medication people have as part of their treatment. Researchers need to do further studies to find this out. 

But this trial helped them learn more about recovery of the immune system and GvHD. 

More detailed information
There is more information about this research in the reference below. 

Please note, this article is not in plain English. It has been written for health care professionals and researchers.

Journal articles
Immunotherapy with CD25/CD71-allodepleted T cells to Improve T-cells reconstitution after matched unrelated donor hemopoietic stem cell transplant: a randomized trial 

Karl S. Peggs, Sarah J. Albon and others. 

Cytotherapy 2022 pages 1-12.

Where this information comes from    
We have based this summary on the information in the article/s above. This has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.

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

Professor Persis Amrolia

Supported by

Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer
University College London (UCL)

If you have questions about the trial please contact our cancer information nurses

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.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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