A trial looking at treatment for acute myeloid leukaemia and high risk myelodysplastic syndrome - intensive treatment group (AML16)

The researchers have produced results from the parts of the trial that looked at 

• Gemtuzumab ozogamicin (also known as Mylotarg or GO)
• The combination of daunorubicin and cytarabine compared to the combination of daunorubicin and clofarabine
• Adding a 3rd cycle of chemotherapy

GO is a monoclonal antibody that is attached to a chemotherapy drug called calicheamicin (pronounced cal-ick-ee-my-sin).The trial team found that adding GO to induction chemotherapy reduced the risk of leukaemia coming back.

The people taking part in the trial were put into treatment groups at random. Neither the person taking part nor their doctor could decide which group they were in. This is called randomisation. Between 2006 and 2010, the trial recruited 1,115 people into 4 treatment groups. They had 1 of the following drug combinations

• Daunorubicin and cytarabine
• Daunorubcin, cytarabine and a single dose of GO
• Daunorubicin and clofarabine
• Daunorubcin, clofarabine and a single dose of GO

The people taking part had not had any other treatment for AML or MDS and their average age was 67. Everybody had 2 cycles of chemotherapy. If their AML or MDS had completely disappeared after the 1st or 2nd cycle (they were in remission ), they could be randomised again to have either another cycle of chemotherapy or to stop at 2 cycles.

After the last cycle of chemotherapy, some people were able to have a stem cell transplant. The people who weren’t able to have a transplant could be randomised once more to have maintenance treatment with the drug azacitidine or to have no further treatment.

In 2012, the trial team published results showing the effect of having gemtuzumab ozogamicin (GO).

Of the people who went into remission, AML or MDS came back in fewer people who had GO with chemotherapy than people who had chemotherapy alone.

The researchers followed the progress of the people taking part and found that after 2 years

• 35% of people who had GO with chemotherapy were still alive
• 29% of people who had chemotherapy alone were still alive

Adding GO to chemotherapy did not really cause any more side effects, apart from slightly more severe sickness and sore mouth in the 1st cycle of treatment.

The trial team concluded that people who had GO with chemotherapy had a lower risk of leukaemia or MDS coming back and lived longer than people who had chemotherapy alone.

The researchers have also published results form the comparison of different chemotherapy drugs and number of treatment cycles. When they compared the combination of daunorubicin and cytarabine with the combination of daunorubicin and clofarabine, they found there wasn't any difference in the response rate or in the average length of time people lived for.

They also found that there was no significant benefit to people having a 3rd cycle of chemotherapy overall, but further work is needed to find out if some subgroups of patients might benefit.

The researchers need to follow up the patients for longer before analysing the results from other drugs looked at in the trial.

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 ) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.