A trial looking at chemotherapy for children and young people with acute lymphoblastic leukaemia (UKALL 2003)

Cancer type:

Acute leukaemia
Acute lymphoblastic leukaemia (ALL)
Children's cancers




Phase 3

This was a trial to find out whether children could have less intensive treatment for acute lymphoblastic leukaemia (ALL) if their leukaemia was considered to be at low risk of coming back. The trial was for children and young people up to the age of 25.

Children with ALL usually have treatment with a number of different chemotherapy drugs. The first stage of treatment for ALL is called induction treatment. It aims to get rid of the cancer, but you then go on to have other stages of treatment called consolidation, interim maintenance and intensification.

Doctors look at a number of factors when making decisions about the exact treatment you have at each stage, including how well the treatment has worked so far.

Bone marrow tests can show the number of leukaemia cells in the bone marrow Open a glossary item. But in this trial, doctors were using a test that can show if small numbers of leukaemia cells had been left behind. This is called minimal residual disease (MRD). Doctors thought that MRD may be better at showing how well leukaemia had responded to treatment and how likely it was to come back.

If doctors knew whose leukaemia was less likely to come back, those people could have less treatment. The treatment used for leukaemia causes some serious side effects, so it is important that people don’t have treatment they don’t need.

The aim of this trial was to see if children and young people with ALL who had a low risk of their leukaemia coming back based on an MRD reading could safely have less intensive treatment.

Summary of results

The researchers found that children and young people who had no residual disease left after induction chemotherapy can safely have less treatment.

The children and young people in this trial had an MRD test at the end of their induction treatment. If this showed there were no leukaemia cells left behind, they were considered to have a low risk of their leukaemia coming back.

Everybody went on to have the next 2 stages of treatment (consolidation and interim maintenance). But after that, the children and young people considered to be at low risk were put into 1 of 2 treatment groups. Half had 1 course of treatment called delayed intensification. The other half had 2 courses of this treatment.

The researchers looked at the number of children whose leukaemia had come back. After an average of nearly 5 years of follow up, they found there was very little difference between the 2 groups.

They concluded that is possible to reduce the amount of treatment children and young people have based on an MRD test at the end of induction treatment.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

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 Ajay Vora

Supported by

Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
National Institute for Health Research Cancer Research Network (NCRN)
University of Sheffield

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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.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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