A trial comparing standard chemotherapy with a less intensive approach for acute promyelocytic leukaemia, with or without gemtuzumab ozogamicin (AML15)

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Cancer type:

Acute leukaemia
Acute myeloid leukaemia (AML)
Blood cancers




Phase 3

This trial was to see if longer but less intensive chemotherapy worked as well as standard Open a glossary item chemotherapy for acute promyelocytic leukaemia (APML). And to see if adding a drug called gemtuzumab ozogamicin (also known as Mylotarg) improved either treatment plan.

More about this trial

APML is a type of acute myeloid leukaemia. Since the discovery of a drug called tretinoin (ATRA), the cure rates for APML had improved a lot. Research in Spain and Italy had then suggested that less intensive chemotherapy, also with tretinoin, may produce results that were just as good, if not better. This type of treatment has fewer side effects than the intensive combinations of drugs usually used in the UK. Patients may spend less time in hospital and have fewer days at risk of infections, but the treatment does go on for longer.

This trial was comparing the intensive chemotherapy usually used here with the less intensive Spanish approach to see which was better at curing APML with the fewest side effects. Everyone in this trial had tretinoin.

The trial also looked at a monoclonal antibody called gemtuzumab ozogamicin to see if adding it to the standard UK or Spanish approaches improved the cure rate for APML.

We also have information on the database about another part of the AML 15 trial for people with other types of acute myeloid leukaemia.

Summary of results

The trial team found that both treatment plans achieved similar results, but people having the less intensive treatment spent less time in hospital. They also found that adding gemtuzumab ozogamicin didn’t improve either treatment.

The trial recruited 285 people with acute promyelocytic leukaemia. Their average age was 42.They were put into 1 of 4 groups at random.

Group 1 had the usual UK chemotherapy including the drugs daunorubicin, cytarabine, etoposide, amsacrine and mitoxantrone, as well as having tretinoin.

Group 2 had the same, but with gemtuzumab ozogamicin added to the 3rd cycle of treatment.

Group 3 had the less intensive Spanish chemotherapy which included the drugs idarubicin and mitoxantrone as well as having tretinoin. They then had low doses of chemotherapy (maintenance chemotherapy) for 2 years. In this time they had the drugs mercaptopurine, methotrexate and tretinoin.

Group 4 had the same as group 3 but with gemtuzumab ozogamicin added to the 3rd cycle of treatment.

The trial team found that the leukaemia completely disappeared (a complete response) in more than 9 out of 10 people (93%) whichever type of chemotherapy they had. And the number of people alive 5 years later was also about the same – 83% of the people who had standard chemotherapy and 84% of the people who had less intensive chemotherapy.

They looked at how long people spent in hospital and the side effects they had. They found that the average number of days people spent in hospital was

  • 82 for people having standard chemotherapy
  • 63 for people having less intensive chemotherapy

People having standard chemotherapy had more hair loss and worse diarrhoea. Overall, the way people rated their quality of life was no worse with the less intensive chemotherapy, and during treatment, quality of life was better for people having less intensive treatment.

The trial team found that adding gemtuzumab ozogamicin didn’t make any difference to the outcome of treatment.

They concluded that the more intensive chemotherapy is not necessary for people with acute promyelocytic leukaemia.

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 A.K. Burnett

Supported by

Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer

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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.

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

Last reviewed:

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