In the Netherlands, about 25 children are diagnosed with AML each year. In these children there is an uninhibited division and growth of a certain type of blood cells. Usually these are white blood cells, sometimes red blood cells or platelets. This leaves no room for the production of healthy blood cells.
Cure rate doubled since 1990s
New research shows that the five-year survival rate for children with AML has increased to 80%, where it was 70% about 10 years ago and 40 in the 1990s. In addition, the chance of the disease recurring fell by 15% from 40% to 25%. Data from 287 children were used for the study. The study was led by the University of Gothenburg and was published today in the journal Journal of Clinical Oncology.
Prof. dr. Gertjan Kaspers, pediatric oncologist and AML specialist, participated in the study on behalf of the Netherlands and is international principal investigator of the CHIP-AML22 study. He says, 'It's great that the chance of survival has increased and the chance of the disease returning has decreased. With the new CHIP-AML study, we want to increase the odds even further. To this end, we are investigating whether we can improve the treatment of children by tailoring it to their risk profile. We are also studying the effectiveness of two new targeted drugs. Both may become standard part of the treatment of AML after the study.'
Risk groups
Changes in the DNA of tumor cells and the effect of initial treatment give strong indications of how the disease will progress in this person. This forms the basis of so-called risk profiling. In the new study, we investigate whether low- and standard-risk children can receive four instead of five courses of chemotherapy. Dr. Bianca Goemans, pediatric oncologist specialized in AML and principal investigator of the CHIP-AML22 study at the Máxima Center: 'We have strong indications that four chemotherapy treatments could be sufficient for these children. Giving one less treatment shortens the duration of treatment and reduces side effects. We now want to demonstrate this through a so-called randomized study, in which 600 children and young adults will be given four or five chemotherapy treatments by drawing lots.'
The researchers will also look at whether, for certain children at higher risk of disease recurrence, it would be better to receive a stem cell transplant as part of the initial treatment.
Effect of targeted drugs
In the CHIP-AML22 study, the researchers are also looking at the effect of a new drug for children with a high-risk form of AML. Kaspers: 'In these children, the leukemia cells have an abnormality in the FLT3 gene. That seems to be an ideal target for quizartinib. By adding it to regular chemotherapy, we hope that the chances of the treatment failing or the leukemia returning will be much lower. In previous studies in adults and a small group of children, this drug that specifically "attacks" the abnormal FLT3 protein was found to have a positive effect when combined with chemotherapy. We are now going to further investigate the amount of drug to be given and the effect.' By collecting sufficient research data, approval for future use in children with AML can then be sought from authorities FDA and EMA.
Also, in a group of children in a phase 3 study, the addition of another targeted drug, Mylotarg, to initial chemotherapy treatment is being investigated. By linking this substance to an antibody, this drug binds directly to the cancer cell. It is more selective than other commonly used types of chemotherapy and therefore has fewer side effects. Mylotarg has been administered for some time and is effective in a proportion of children with AML. The drug has already been approved in the Netherlands as the first treatment for children with AML aged 15 years and older. In the United States, it is approved for all children and adolescents with AML.
By drawing lots, some of the children in the CHIP-AML22 study will receive Mylotarg during their first treatment with chemotherapy. In this way, we will study whether the addition improves the chances of cure. In total, more than 900 children will participate in the CHIP-AML22 study, including about 100 from the Princess Máxima Center.